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Page 1: Vibration Monitoring, Testing, and Instrumentationpreview.kingborn.net › 646000 › d1a74678d91943e5ba1d5e... · The MEMS Handbook, Second Edition MEMS: Introduction and Fundamentals

53191mdash1432007mdash1849mdashVELUmdash246493mdash CRC ndash pp 1ndash15

copy 2007 by Taylor amp Francis Group LLC

Vibration MonitoringTesting and

Instrumentation

copy 2007 by Taylor amp Francis Group LLC

Mechanical Engineering SeriesFrank Kreith and Roop Mahajan - Series Editors

Published Titles

Computer Techniques in VibrationClarence W de SilvaDistributed Generation The Power Paradigm forthe New MillenniumAnne-Marie Borbely ampJan F KreiderElastoplasticity TheoryVlado A LubardaEnergy Audit of Building SystemsAn Engineering ApproachMoncefKrartiEngineering ExperimentationEuan SomerscalesEntropy Generation MinimizationAdrian BejanFinite Element Method Using MATLABreg2 n d EditionYoung W Kwon amp Hyochoong BangFluid Power Circuits and Controls Fundamentalsand ApplicationsJohn S CundiffFundamentals of Environmental DischargeModelingLorin R DavisHeat Transfer in Single and Multiphase SystemsGregF NatererIntroductory Finite Element MethodChandrakant S Desai amp Tribikram KunduIntelligent Transportation Systems New Principlesand ArchitecturesSumit Ghosh amp Tony LeeMathematical amp Physical Modeling of MaterialsProcessing OperationsOlusegun Johnson Ilegbusi Manabu Iguchi ampWalter E WahnsiedlerMechanics of Composite MaterialsAutarK Kaw

Mechanics of FatigueVladimir V BolotinMechanics of Solids and Shells Theories andApproximationsGerald Wempner amp Demosthenes TalaslidisMechanism Design Enumeration of KinematicStructures According to FunctionLung-Wen Tsai

The MEMS Handbook Second EditionMEMS Introduction and FundamentalsMEMS Design and FabricationMEMS Applications

Mohamed Gad-el-HakNanotechnology Understanding Small SystemsBen Rogers Jesse Adams amp Sumita PennathurNonlinear Analysis of StructuresM SathyamoorthyPractical Inverse Analysis in EngineeringDavid M Trujillo amp Henry R BusbyPressure Vessels Design and PracticeSomnath ChattopadhyayPrinciples of Solid MechanicsRowland Richards JrThermodynamics for EngineersKau-Fui WongVibration Damping Control and DesignClarence W de SilvaVibration Monitoring Testing and InstrumentationClarence W de SilvaVibration and Shock HandbookClarence W de SilvaViscoelastic SolidsRoderic S Lakes

copy 2007 by Taylor amp Francis Group LLC

Vibration MonitoringTesting and

Instrumentation

Edited by

Clarence W de SilvaThe University of British Columbia

Vancouver Canada

Ltfi) CRC PressVV^ J Taylor amp Francis Group

Boca Raton London New York

CRC Press is an imprint of theTaylor amp Francis Croup an informa business

copy 2007 by Taylor amp Francis Group LLC

This material was previously published in Vibration and Shock Handbook copy 2005 by CRC Press LLC

CRC PressTaylor amp Francis Group6000 Broken Sound Parkway NW Suite 300Boca Raton FL 33487-2742

copy 2007 by Taylor amp Francis Group LLCCRC Press is an imprint of Taylor amp Francis Group an Informa business

No claim to original US Government worksPrinted in the United States of America on acid-free paper10987654321

International Standard Book Number-101-4200-5319-1 (Hardcover)International Standard Book Number-13978-1-4200-5319-7 (Hardcover)

This book contains information obtained from authentic and highly regarded sources Reprinted material is quotedwith permission and sources are indicated A wide variety of references are listed Reasonable efforts have been made topublish reliable data and information but the author and the publisher cannot assume responsibility for the validity ofall materials or for the consequences of their use

No part of this book may be reprinted reproduced transmitted or utilized in any form by any electronic mechanical orother means now known or hereafter invented including photocopying microfilming and recording or in any informa-tion storage or retrieval system without written permission from the publishers

For permission to photocopy or use material electronically from this work please access wwwcopyrightcom (httpwwwcopyrightcom) or contact the Copyright Clearance Center Inc (CCC) 222 Rosewood Drive Danvers MA 01923978-750-8400 CCC is a not-for-profit organization that provides licenses and registration for a variety of users For orga-nizations that have been granted a photocopy license by the CCC a separate system of payment has been arranged

Trademark Notice Product or corporate names may be trademarks or registered trademarks and are used only foridentification and explanation without intent to infringe

Library of Congress Cataloging-in-Publication Data

Vibration monitoring testing and instrumentation editor Clarence W de Silvap cm mdash (Mechanical engineering series)

Includes bibliographical references and indexISBN-13 978-1-4200-5319-7 (alk paper)ISBN-101-4200-5319-1 (alk paper)1 Vibration 2 Shock (Mechanics) I De Silva Clarence W II Title III Series

TA355V5228 200762030287-dc22 2006100139

Visit the Taylor amp Francis Web site athttpwwwtaylorandfranciscom

and the CRC Press Web site athttpwwwcrcpresscom

copy 2007 by Taylor amp Francis Group LLC

Preface

Individual chapters authored by distinguished leaders and experienced professionals in their

respective topics this book provides for engineers technicians designers researchers educators and

students a convenient thorough up-to-date and authoritative reference source on techniques tools

and data for monitoring testing and instrumentation of mechanical vibration and shock Included

are shock and vibration methodologies particularly for civil and mechanical engineering systems

instrumentation and testing methods including sensors exciters signal acquisition conditioning

and recording and LabVIEWw tools for virtual instrumentation testing and design for seismic

vibration and related regulatory issues and human response to vibration Important information

and results are summarized as windows tables graphs and lists throughout the chapters for easy

reference and information tracking References are given at the end of each chapter for further

information and study Cross-referencing is used throughout to indicate other places in the book

where further information on a particular topic is provided

In the book equal emphasis is given to theory and practical application Analytical

formulations design approaches monitoring and testing techniques and commercial software

tools are presented and illustrated Commercial equipment computer hardware and instrumenta-

tion are described analyzed and demonstrated for field application practical implementation and

experimentation Examples and case studies are given throughout the book to illustrate the use

and application of the included information The material is presented in a format that is

convenient for easy reference and recollection

Mechanical vibration is a manifestation of the oscillatory behavior in mechanical systems as a

result of either the repetitive interchange of kinetic and potential energies among components in

the system or a forcing excitation that is oscillatory Such oscillatory responses are not limited to

purely mechanical systems and are found in electrical and fluid systems as well In purely thermal

systems however free natural oscillations are not possible and an oscillatory excitation is needed

to obtain an oscillatory response Sock is vibration caused by brief abrupt and typically high-

intensity excitations Low levels of vibration mean reduced noise and improved work environment

Consequently a considerable effort is devoted today to monitoring studying and modifying the

vibration and shock generated by machinery components machine tools transit vehicles impact

processes civil engineering structures fluid flow systems and aircraft Before designing a system

for good vibratory or shock performance it is important to understand analyze and represent the

dynamic characteristics of the system This may be accomplished through monitoring testing and

analysis of test data which is the emphasis of this book

In recent years educators researchers and practitioners have devoted considerable effort towards

studying monitoring and testing vibration and shock in a range of applications in various branches

of engineering particularly civil mechanical aeronautical and aerospace and production and

v

53191mdash1432007mdash1850mdashVELUmdash246493mdash CRC ndash pp 1ndash15

copy 2007 by Taylor amp Francis Group LLC

manufacturing Specific applications are found in machine tools transit vehicles impact processes

civil engineering structures construction machinery industrial processes product qualification and

quality control fluid flow systems ships and aircraft This book is a contribution towards these

efforts

Clarence W de SilvaEditor-in-Chief

Vancouver Canada

Prefacevi

53191mdash1432007mdash1850mdashVELUmdash246493mdash CRC ndash pp 1ndash15

copy 2007 by Taylor amp Francis Group LLC

Acknowledgments

I wish to express my gratitude to the authors of the chapters for their valuable and highly professional

contributions I am very grateful to Michael Slaughter Acquisitions Editor-Engineering CRC Press for

his enthusiasm and support throughout the project Editorial and production staff at CRC Press have

done an excellent job in getting this volume out in print Finally I wish to lovingly acknowledge the

patience and understanding of my family

vii

53191mdash1432007mdash1850mdashVELUmdash246493mdash CRC ndash pp 1ndash15

copy 2007 by Taylor amp Francis Group LLC

Editor-in-Chief

Dr Clarence W de Silva PEng Fellow ASME Fellow IEEE Fellow Canadian Academy of

Engineering is Professor of Mechanical Engineering at the University of British Columbia Vancouver

Canada and has occupied the NSERC-BC Packers Research Chair in Industrial Automation since 1988

He has earned PhD degrees from the Massachusetts Institute of Technology and the University of

Cambridge England De Silva has also occupied the Mobil Endowed Chair Professorship in the

Department of Electrical and Computer Engineering at the National University of Singapore He has

served as a consultant to several companies including IBM and Westinghouse in US and has led the

development of eight industrial machines and devices He is recipient of the Henry M Paynter

Outstanding Investigator Award from the Dynamic Systems and Control Division of the American

Society of Mechanical Engineers (ASME) Killam Research Prize Lifetime Achievement Award from the

World Automation Congress Outstanding Engineering Educator Award of IEEE Canada Yasundo

Takahashi Education Award of the Dynamic Systems and Control Division of ASME IEEE Third

Millennium Medal Meritorious Achievement Award of the Association of Professional Engineers of BC

and the Outstanding Contribution Award of the Systems Man and Cybernetics Society of the Institute

of Electrical and Electronics Engineers (IEEE)

He has authored 16 technical books including Sensors and Actuators Control System Instrumentation

(Taylor amp Francis CRC Press 2007) MechatronicsmdashAn Integrated Approach (Taylor amp Francis CRC

Press Boca Raton FL 2005) Soft Computing and Intelligent Systems DesignmdashTheory Tools and

Applications (with F Karry Addison Wesley New York NY 2004) VIBRATION Fundamentals and

Practice (Taylor amp Francis CRC Press 2nd edition 2006) INTELLIGENT CONTROL Fuzzy Logic

Applications (Taylor amp Francis CRC Press 1995) Control Sensors and Actuators (Prentice Hall 1989) 14

edited volumes over 170 journal papers 200 conference papers and 12 book chapters He has served on

the editorial boards of 14 international journals in particular as the Editor-in-Chief of the International

Journal of Control and Intelligent Systems Editor-in-Chief of the International Journal of Knowledge-Based

Intelligent Engineering Systems Senior Technical Editor of Measurements and Control and Regional

Editor North America of Engineering Applications of Artificial Intelligence ndash the International Journal of

Intelligent Real-Time Automation He is a Lilly Fellow at Carnegie Mellon University NASA-ASEE Fellow

Senior Fulbright Fellow at Cambridge University ASI Fellow and a Killam Fellow Research and

development activities of Professor de Silva are primarily centered in the areas of process automation

robotics mechatronics intelligent control and sensors and actuators with cash funding of about $6

million as principal investigator

ix

53191mdash1432007mdash1850mdashVELUmdash246493mdash CRC ndash pp 1ndash15

copy 2007 by Taylor amp Francis Group LLC

Contributors

xi

Kourosh DanaiUniversity of Massachusetts

Amherst Massachusetts

Clarence W de SilvaThe University of British Columbia

Vancouver British Columbia Canada

P S HeynsUniversity of Pretoria

Pretoria South Africa

S HuangNational University of Singapore

Singapore

Hirokazu IemuraKyoto University

Kyoto Japan

Sarvesh Kumar JainMadhav Institute of Technology and

Science

Madhya Pradesh India

Christian LalanneEngineering Consultant

Jalles France

TH LeeNational University of Singapore

Singapore

YP LeowSingapore Institute of Manufacturing

Technology

Singapore

SY LimSingapore Institute of Manufacturing

Technology

Singapore

Jiaohao LinDalian University of Technology

Liaoning Peoplersquos Republic of China

W LinSingapore Institute of Manufacturing

Technology

Singapore

Chris K MechefskeQueenrsquos University

Kingston Ontario Canada

Priyan MendisUniversity of Melbourne

Melbourne Victoria Australia

Tuan NgoUniversity of Melbourne

Melbourne Victoria Australia

Mulyo Harris PradonoKyoto University

Kyoto Japan

C SchefferUniversity of Stellenbosch

Pretoria South Africa

KK TanNational University of Singapore

Singapore

KZ TangNational University of Singapore

Singapore

Yahui ZhangDalian University of Technology

Liaoning Peoplersquos Republic of China

53191mdash1432007mdash1850mdashVELUmdash246493mdash CRC ndash pp 1ndash15

copy 2007 by Taylor amp Francis Group LLC

Contents

1 Vibration Instrumentation Clarence W de Silva 1-1

11 Introduction 1-1

12 Vibration Exciters 1-3

13 Control System 1-15

14 Performance Specification 1-21

15 Motion Sensors and Transducers 1-27

16 Torque Force and Other Sensors 1-50

Appendix 1A Virtual Instrumentation for Data Acquisition Analysis

and Presentation 1-73

2 Signal Conditioning and Modification Clarence W de Silva 2-1

21 Introduction 2-2

22 Amplifiers 2-2

23 Analog Filters 2-15

24 Modulators and Demodulators 2-29

25 AnalogndashDigital Conversion 2-37

26 Bridge Circuits 2-43

27 Linearizing Devices 2-49

28 Miscellaneous Signal Modification Circuitry 2-56

29 Signal Analyzers and Display Devices 2-62

3 Vibration Testing Clarence W de Silva 3-1

31 Introduction 3-1

32 Representation of a Vibration Environment 3-3

33 Pretest Procedures 3-24

34 Testing Procedures 3-37

35 Some Practical Information 3-52

4 Experimental Modal Analysis Clarence W de Silva 4-1

41 Introduction 4-1

42 Frequency-Domain Formulation 4-2

43 Experimental Model Development 4-8

44 Curve Fitting of Transfer Functions 4-10

45 Laboratory Experiments 4-18

46 Commercial EMA Systems 4-24

xiii

53191mdash1432007mdash1850mdashVELUmdash246493mdash CRC ndash pp 1ndash15

copy 2007 by Taylor amp Francis Group LLC

5 Mechanical Shock Christian Lalanne 5-1

51 Definitions 5-2

52 Description in the Time Domain 5-3

53 Shock Response Spectrum 5-4

54 Pyroshocks 5-17

55 Use of Shock Response Spectra 5-18

56 Standards 5-24

57 Damage Boundary Curve 5-26

58 Shock Machines 5-28

59 Generation of Shock Using Shakers 5-44

510 Control by a Shock Response Spectrum 5-52

511 Pyrotechnic Shock Simulation 5-58

6 Machine Condition Monitoring and Fault Diagnostics Chris K Mechefske 6-1

61 Introduction 6-2

62 Machinery Failure 6-2

63 Basic Maintenance Strategies 6-4

64 Factors Which Influence Maintenance Strategy 6-7

65 Machine Condition Monitoring 6-8

66 Transducer Selection 6-10

67 Transducer Location 6-14

68 Recording and Analysis Instrumentation 6-14

69 Display Formats and Analysis Tools 6-16

610 Fault Detection 6-21

611 Fault Diagnostics 6-25

7 Vibration-Based Tool Condition Monitoring Systems C Scheffer and PS Heyns 7-1

71 Introduction 7-1

72 Mechanics of Turning 7-2

73 Vibration Signal Recording 7-7

74 Signal Processing for Sensor-Based Tool Condition Monitoring 7-11

75 Wear ModelDecision-Making for Sensor-Based Tool Condition Monitoring 7-15

76 Conclusion 7-20

8 Fault Diagnosis of Helicopter Gearboxes Kourosh Danai 8-1

81 Introduction 8-1

82 Abnormality Scaling 8-5

83 The Structure-Based Connectionist Network 8-8

84 Sensor Location Selection 8-11

85 A Case Study 8-14

86 Conclusion 8-23

9 Vibration Suppression and Monitoring in Precision Motion Systems KK Tan

TH Lee KZ Tang S Huang SY Lim W Lin and YP Leow 9-1

91 Introduction 9-1

92 Mechanical Design to Minimize Vibration 9-2

93 Adaptive Notch Filter 9-10

94 Real-Time Vibration Analyzer 9-17

Contentsxiv

53191mdash1432007mdash1850mdashVELUmdash246493mdash CRC ndash pp 1ndash15

copy 2007 by Taylor amp Francis Group LLC

95 Practical Insights and Case Study 9-29

96 Conclusions 9-35

10 Vibration and Shock Problems of Civil Engineering Structures Priyan Mendis

and Tuan Ngo 10-1

101 Introduction 10-2

102 Earthquake-Induced Vibration of Structures 10-3

103 Dynamic Effects of Wind Loading on Structures 10-22

104 Vibrations Due to FluidndashStructure Interaction 10-33

105 Blast Loading and Blast Effects on Structures 10-34

106 Impact Loading 10-47

107 Floor Vibration 10-51

11 Seismic Base Isolation and Vibration Control Hirokazu Iemura Sarvesh Kumar Jain

and Mulyo Harris Pradono 11-1

111 Introduction 11-1

112 Seismic Base Isolation 11-4

113 Seismic Vibration Control 11-33

12 Seismic Random Vibration of Long-Span Structures Jiahao Lin and Yahui Zhang 12-1

121 Introduction 12-2

122 Seismic Random-Excitation Fields 12-11

123 Pseudoexcitation Method for Structural Random Vibration Analysis 12-16

124 Long-Span Structures Subjected to Stationary Random Ground Excitations 12-27

125 Long-Span Structures Subjected to Nonstationary Random Ground Excitations 12-34

126 Conclusions 12-39

13 Seismic Qualification of Equipment Clarence W de Silva 13-1

131 Introduction 13-1

132 Distribution Qualification 13-1

133 Seismic Qualification 13-6

14 Human Response to Vibration Clarence W de Silva 14-1

141 Introduction 14-1

142 Vibration Excitations on Humans 14-2

143 Human Response to Vibration 14-3

144 Regulation of Human Vibration 14-6

Contents xv

53191mdash1432007mdash1850mdashVELUmdash246493mdash CRC ndash pp 1ndash15

copy 2007 by Taylor amp Francis Group LLC

1Vibration

Instrumentation

Clarence W de SilvaThe University of British Columbia

11 Introduction 1-1

12 Vibration Exciters 1-3Shaker Selection dagger Dynamics of Electromagnetic Shakers

13 Control System 1-15Components of a Shaker Controller dagger Signal-Generating

Equipment

14 Performance Specification 1-21Parameters for Performance Specification dagger Linearity dagger

Instrument Ratings dagger Accuracy and Precision

15 Motion Sensors and Transducers 1-27Potentiometer dagger Variable-Inductance Transducers dagger

Mutual-Induction Proximity Sensor dagger Selfinduction

Transducers dagger Permanent-Magnet Transducers dagger

Alternating Current Permanent-Magnet Tachometer dagger

Alternating Current Induction Tachometer dagger Eddy Current

Transducers dagger Variable-Capacitance Transducers dagger

Piezoelectric Transducers

16 Torque Force and Other Sensors 1-50Strain Gage Sensors dagger Miscellaneous Sensors

Appendix 1A Virtual Instrumentation for DataAcquisition Analysis and Presentation 1-73

Summary

Devices useful in instrumenting a mechanical vibrating system are presented in this chapter Shakers whichgenerate vibration excitations are discussed and compared A variety of sensors including motion sensorsproximity sensors forcetorque sensors and other miscellaneous sensors are considered Performance specificationin the time domain and the frequency domain is addressed Rating parameters of instruments are given

11 Introduction

Measurement and associated experimental techniques play a significant role in the practice of vibration

Academic exposure to vibration instrumentation usually arises in laboratories in the context of learning

training and research In vibration practice perhaps the most important task of instrumentation is the

measurement or sensing of vibration Vibration sensing is useful in the following applications

1 Design and development of a product

2 Testing (screening) of a finished product for quality assurance

3 Qualification of a good-quality product to determine its suitability for a specific application

1-1

53191mdash522007mdash1201mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

4 Mechanical aging of a product prior to carrying out a test program

5 Exploratory testing of a product to determine its dynamic characteristics such as resonances

mode shapes and even a complete dynamic model

6 Vibration monitoring for performance evaluation

7 Control and suppression of vibration

Figure 11 indicates a procedure typical of experimental vibration highlighting the essential

instrumentation Vibrations are generated in a device the test object in response to some excitation In

some experimental procedures primarily in vibration testing (see Figure 11) the excitation signal has

to be generated in a signal generator in accordance with some requirement (specification) and applied to

the object through an exciter after amplification and conditioning In some other situations primarily in

performance monitoring and vibration control the excitations are generated as an integral part of the

operating environment of the vibrating object and may originate either within the object (eg engine

excitations in an automobile) or in the environment with which the object interacts during operation

(eg road disturbances on an automobile) Sensors are needed to measure vibrations in the test object In

particular a control sensor is used to check whether the specified excitation is applied to the object

and one or more response sensors may be used to measure the resulting vibrations at key locations of

the object

The sensor signals have to be properly conditioned for example by filtering and amplification and

modified for example through modulation demodulation and analog-to-digital conversion prior to

recording analyzing and display The purpose of the controller is to guarantee that the excitation is

correctly applied to the test object If the signal from the control sensor deviates from the required

excitation the controller modifies the signal to the exciter so as to reduce this deviation Furthermore the

controller will stabilize or limit (compress) the vibrations in the object It follows that instruments in

experimental vibration may be generally classified into the following categories

1 Signal-generating devices

2 Vibration exciters

3 Sensors and transducers

4 Signal conditioningmodifying devices

5 Signal analysis devices

6 Control devices

7 Vibration recording and display devices

AnalogDigital

Interface

DigitalSignal

RecorderAnalyzerDisplay

FilterAmplifier

FilterAmplifier

SignalGenerator

and ExciterController

Reference (Required)Signal (Specification)

PowerAmplifier

MountingFixtures

TestObject

ResponseSensor

ControlSensor

Exciter

SwivelBase

FIGURE 11 Typical instrumentation in experimental vibration

Vibration Monitoring Testing and Instrumentation1-2

53191mdash522007mdash1201mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

Note that one instrument may perform the tasks

of more than one category listed here Also more

than one instrument may be needed to carry out

tasks in a single category In the following sections

we will provide some examples of the types of

vibration instrumentation giving characteristics

operating principles and important practical

considerations Also we will describe several

experiments which can be found in a typical

vibration laboratory

An experimental vibration system generally

consists of four main subsystems

1 Test object

2 Excitation system

3 Control system

4 Signal acquisition and modification system

These are schematically shown in Figure 12 Note that various components shown in Figure 11 may

be incorporated into one of these subsystems In particular component matching hardware and object

mounting fixtures may be considered interfacing devices that are introduced through the interaction

between the main subsystems as shown in Figure 12 Some important issues of vibration testing and

instrumentation are summarized in Box 11

12 Vibration Exciters

Vibration experimentation may require an external exciter to generate the necessary vibration This is the

case in controlled experiments such as product testing where a specified level of vibration is applied to the

test object and the resulting response is monitored A variety of vibration exciters are available with

different capabilities and principles of operation

Three basic types of vibration exciters (shakers) are widely used hydraulic shakers inertial shakers

and electromagnetic shakers The operation-capability ranges of typical exciters in these three categories

are summarized in Table 11 Stroke or maximum displacement is the largest displacement the exciter

is capable of imparting onto a test object whose weight is assumed to be within its design load limit

Maximum velocity and acceleration are similarly defined Maximum force is the largest force that could

be applied by the shaker to a test object of acceptable weight (one within the design load) The values

given in Table 11 should be interpreted with caution Maximum displacement is achieved only at very

low frequencies The achievement of maximum velocity corresponds to intermediate frequencies in the

operating frequency range of the shaker Maximum acceleration and force ratings are usually achieved at

high frequencies It is not feasible for example to operate a vibration exciter at its maximum

displacement and its maximum acceleration simultaneously

Consider a loaded exciter that is executing harmonic motion Its displacement is given by

x frac14 s sin vt eth11THORN

in which s is the displacement amplitude (or stroke) Corresponding velocity and acceleration are

_x frac14 sv cos vt eth12THORN

eurox frac14 2sv2sin vt eth13THORN

SignalModification

System

TestObject

ControlSystem

VibrationExciter (Shaker)

System

FIGURE 12 Interactions between major subsystems of

an experimental vibration system

Vibration Instrumentation 1-3

53191mdash522007mdash1201mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

If the velocity amplitude is denoted by v and the acceleration amplitude by a it follows from Equation

12 and Equation 13 thatv frac14 vs eth14THORN

and

a frac14 vv eth15THORN

Box 11

VIBRATION INSTRUMENTATION

Vibration Testing Applications for Products

Design and Development Production Screening and Quality Assessment Utilization and Qualification for Special Applications

Testing Instrumentation

Exciter (excites the test object) Controller (controls the exciter for accurate excitation) Sensors and Transducers (measure excitations and responses and provide excitation error

signals to controller) Signal Conditioning (converts signals to appropriate form) Recording and Display (perform processing storage and documentation)

Exciters

Shakers

1 Electrodynamic (high bandwidth moderate power complex and multifrequency

excitations)

2 Hydraulic (moderate to high bandwidth high power complex and multifrequency

excitations)

3 Inertial (low bandwidth low power single-frequency harmonic excitations)

TransientInitial Condition

1 Hammers (impulsive bump tests)

2 Cable Release (step excitations)

3 Drop (impulsive)

Signal Conditioning

Filters Amplifiers Amplifiers ModulatorsDemodulators ADCDAC

Sensors

Motion (displacement velocity acceleration) Force (strain torque)

Vibration Monitoring Testing and Instrumentation1-4

53191mdash522007mdash1201mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

TABLE 11 Typical Operation-Capability Ranges for Various Shaker Types

Shaker Type Typical Operational Capabilities

Frequency Maximum Displacement

(Stroke)

Maximum

Velocity

Maximum

Acceleration

Maximum

Force

Excitation

Waveform

Hydraulic

(electrohydraulic)

Low

(01ndash500 Hz)

High (20 in 50 cm) Intermediate

(50 insec

125 cmsec)

Intermediate

(20 g)

High (100000 lbf

450000 N)

Average flexibility (simple

to complex and random)

Inertial

(counter-rotating mass)

Intermediate

(2ndash50 Hz)

Low (1 in 25 cm) Intermediate

(50 insec

125 cmsec)

Intermediate

(20 g)

Intermediate

(1000 lbf 4500 N)

Sinusoidal only

Electromagnetic

(electrodynamic)

High

(2ndash10000 Hz)

Low (1 in 25 cm) Intermediate

(50 insec

125 cmsec)

High (100 g) Low to intermediate

(450 lbf 2000 N)

High flexibility and accuracy

(simple to complex and

random)

VibrationInstru

mentation

1-5

53191mdash522007mdash

1201mdashSENTHILKUMARmdash246494mdash

CRCndashpp1ndash112

copy 2007 by Taylor amp Francis Group LLC

An idealized performance curve of a shaker

has a constant displacementndashamplitude region a

constant velocityndashamplitude region and a con-

stant accelerationndashamplitude region for low

intermediate and high frequencies respectively

in the operating frequency range Such an ideal

performance curve is shown in Figure 13(a) on a

frequencyndashvelocity plane Logarithmic axes are

used In practice typical shaker performance

curves would be fairly smooth yet nonlinear

curves similar to those shown in Figure 13(b)

As the mass increases the performance curve

compresses Note that the acceleration limit of a

shaker depends on the mass of the test object

(load) Full load corresponds to the heaviest object

that could be tested The ldquono loadrdquo condition

corresponds to a shaker without a test object To

standardize the performance curves they are

usually defined at the rated load of the shaker A

performance curve in the frequencyndashvelocity

plane may be converted to a curve in the

frequencyndashacceleration plane simply by increasing

the slope of the curve by a unit magnitude (ie

20 dbdecade)

Several general observations can be made from

Equation 14 and Equation 15 In the constant-

peak displacement region of the performance

curve the peak velocity increases proportionally

with the excitation frequency and the peak

acceleration increases with the square of the excitation frequency In the constant-peak velocity region

the peak displacement varies inversely with the excitation frequency and the peak acceleration increases

proportionately In the constant-peak acceleration region the peak displacement varies inversely with the

square of the excitation frequency and the peak velocity varies inversely with the excitation frequency

This further explains why rated stroke maximum velocity and maximum acceleration values are not

simultaneously realized

121 Shaker Selection

Vibration testing is accomplished by applying a specified excitation to the test package using a shaker

apparatus and monitoring the response of the test object Test excitation may be represented by its

response spectrum The test requires that the response spectrum of the actual excitation known as the

test response spectrum (TRS) envelops the response spectrum specified for the particular test known as

the required response spectrum (RRS)

A major step in the planning of any vibration testing program is the selection of a proper shaker

(exciter) system for a given test package The three specifications that are of primary importance in

selecting a shaker are the force rating the power rating and the stroke (maximum displacement) rating

Force and power ratings are particularly useful in moderate to high frequency excitations and the stroke

rating is the determining factor for low frequency excitations In this section a procedure is given to

determine conservative estimates for these parameters in a specified test for a given test package

Frequency domain considerations are used here

Stroke

Limit M

ax

Acceleration

MaxVelocity

Peak

Vel

ocity

(cm

s)

01 1 10 100

FullLoad

NoLoad

Frequency (Hz)(a)

Peak

Vel

ocity

(cm

s)

100

10

1

100

10

1

01 1 10 100

FullLoad

NoLoad

Frequency (Hz)(b)

FIGURE 13 Performance curve of a vibration exciter

in the frequencyndashvelocity plane (log) (a) ideal (b)

typical

Vibration Monitoring Testing and Instrumentation1-6

53191mdash522007mdash1201mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

1211 Force Rating

In the frequency domain the (complex) force at the exciter (shaker) head is given by

F frac14 mHethvTHORNasethvTHORN eth16THORNin which v is the excitation frequency variable m is the total mass of the test package including

mounting fixture and attachments asethvTHORN is the Fourier spectrum of the support-location (exciter head)

acceleration and H(v) is frequency response function that takes into account the flexibility and

damping effects (dynamics) of the test package apart from its inertia In the simplified case where the

test package can be represented by a simple oscillator of natural frequency vn and damping ratio by zt

this function becomes

HethvTHORN frac14 1thorn 2jztv=vn=12 ethv=vnTHORN2 thorn 2jztv=vn eth17THORNin which j frac14 ffiffiffiffi

21p

This approximation is adequate for most practical purposes The static weight of the

test object is not included in Equation 16 Most heavy-duty shakers which are typically hydraulic

have static load support systems such as pneumatic cushion arrangements that can exactly balance the

dead load The exciter provides only the dynamic force In cases where shaker directly supports the

gravity load in the vertical test configuration Equation 16 should be modified by adding a term to

represent this weight

A common practice in vibration test applications is to specify the excitation signal by its response

spectrum This is simply the peak response of a simple oscillator expressed as a function of its natural

frequency when its support location is excited by the specified signal Clearly the damping of the simple

oscillator is an added parameter in a response spectrum specification Typical damping ratios ethzrTHORN used inresponse spectra specifications are less than 01 (or 10) It follows that an approximate relationship

between the Fourier spectrum of the support acceleration and its response spectrum is

as frac14 2jzrarethvTHORN eth18THORNThe magnitude larethvTHORNl is the response spectrumEquation 18 substituted into Equation 16 gives

F frac14 mHethvTHORN2jzrarethvTHORN eth19THORNIn view of Equation 17 for test packages having low damping the peak value of H(v) is

approximately 1=eth2jztTHORN this should be used in computing the force rating if the test package has a

resonance within the frequency range of testing On the other hand if the test package is assumed to be

rigid then HethvTHORN oslash 1 A conservative estimate for the force rating is

Fmax frac14 methzr=ztTHORNlarethvTHORNlmax eth110THORNIt should be noted that larethvTHORNlmax is the peak value of the specified (required) response spectrum (RRS)

for acceleration

1212 Power Rating

The exciter head does not develop its maximum force when driven at maximum velocity Output power

is determined by using

p frac14 Refrac12FvsethvTHORN eth111THORNin which vsethvTHORN is the Fourier spectrum of the exciter velocity and Re [ ] denotes the real part of a complex

function Note that as frac14 jvvs Substituting Equation 16 and Equation 18 into Equation 111 gives

p frac14 eth4mz2r =vTHORNRefrac12jHethvTHORNa2r ethvTHORN eth112THORNIt follows that a conservative estimate for the power rating is

pmax frac14 2methz2r =ztTHORNfrac12larethvTHORNl2=v max eth113THORN

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Representative segments of typical acceleration RRS curves have slope n as given by

a frac14 k1vn eth114THORN

It should be clear from Equation 113 that the maximum output power is given by

pmax frac14 k2v2n21 eth115THORN

This is an increasing function for n 1=2 and a decreasing function for n 1=2 It follows that the power

rating corresponds to the highest point of contact between the acceleration RRS curve and a line of slope

equal to 12 A similar relationship may be derived if velocity RRS curves (having slopes n2 1) are used

1213 Stroke Rating

From Equation 18 it should be clear that the Fourier spectrum xs of the exciter displacement time

history can be expressed as

xs frac14 2zrarethvTHORN=jv2 eth116THORNAn estimate for stroke rating is

xmax frac14 2zrfrac12larethvTHORNl=v2 max eth117THORNThis is of the form

xmax frac14 kvn22 eth118THORNIt follows that the stroke rating corresponds to the highest point of contact between the acceleration

RRS curve and a line of slope equal to two

Example 11

A test package of overall mass 100 kg is to be

subjected to dynamic excitation represented by the

acceleration RRS (at 5 damping) as shown in

Figure 14 The estimated damping of the test

package is 7 The test package is known to have a

resonance within the frequency range of the

specified test Determine the exciter specifications

for the test

Solution

From the development presented in the previous

section it is clear that the point F (or P) in

Figure 14 corresponds to the force and output

power ratings and the point S corresponds to

the stroke rating The co-ordinates of these

critical points are F P frac14 eth42 Hz 40 gTHORN and S frac14 eth08 Hz 075 gTHORN Equation 110 gives the force

rating as

Fmax frac14 100 pound eth005=007THORN pound 40 pound 981 N frac14 2803 N

Equation 113 gives the power rating as

pmax frac14 2 pound 100 pound eth0052=007THORN pound frac12eth40 pound 981THORN2=42 pound 2p watts frac14 417 W

Equation 117 gives the stroke rating as

xmax frac14 2 pound 005 pound frac12eth075 pound 98THORN=eth08 pound 2pTHORN2 m frac14 3 cm

Acc

eler

atio

n(g

)

Con

stan

t Dis

plac

emen

t

Constant Velo

city

Frequency (Hz)

S

FP

0101

10 10 100

10

10

FIGURE 14 Test excitation specified by an accelera-

tion RRS (5 damping)

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1214 Hydraulic Shakers

A typical hydraulic shaker consists of a piston-cylinder arrangement (also called a ram) a servo-valve a

fluid pump and a driving electric motor Hydraulic fluid (oil) is pressurized (typical operating pressure

4000 psi) and pumped into the cylinder through a servo-valve by means of a pump that is driven by an

electric motor (typical power 150 hp) The flow (typical rate 100 galmin) that enters the cylinder is

controlled (modulated) by the servo-valve which in effect controls the resulting piston (ram) motion

A typical servo-valve consists of a two-stage spool valve which provides a pressure difference and a

controlled (modulated) flow to the piston which sets it in motion

The servo-valve itself is moved by means of a linear torque motor which is driven by the excitation-

input signal (electrical) A primary function of the servo-valve is to provide a stabilizing feedback to the

ram In this respect the servo-valve complements the main control system of the test setup The ram is

coupled to the shaker table by means of a link with some flexibility The cylinder frame is mounted on the

support foundation with swivel joints This allows for some angular and lateral misalignment which

might be caused primarily by test-object dynamics as the table moves

Two-degree-of-freedom (Two-DoF) testing requires two independent sets of actuators and three-DoF

testing requires three independent actuator sets Each independent actuator set can consist of several

actuators operated in parallel using the same pump and the same excitation-input signal to the torque

motors

If the test table is directly supported on the vertical actuators they must withstand the total dead

weight (ie the weight of the test table the test object the mounting fixtures and the instrumentation)

This is requirement is usually prevented by providing a pressurized air cushion in the gap between the

test table and the foundation walls Air should be pressurized so as to balance the total dead weight

exactly (typical required gage pressure 3 psi)

Figure 15(a) shows the basic components of a typical hydraulic shaker The corresponding

operational block diagram is shown in Figure 15(b) It is desirable to locate the actuators in a pit in the

test laboratory so that the test tabletop is flushed with the test laboratory floor under no-load conditions

This minimizes the effort required to place the test object on the test table Otherwise the test object has

to be lifted onto the test table with a forklift Also installation of an aircushion to support the system

dead weight is difficult under these circumstances of elevated mounting

Hydraulic actuators are most suitable for heavy load testing and are widely used in industrial and civil

engineering applications They canbeoperated at very low frequencies (almost direct current [DC]) aswell

as at intermediate frequencies (see Table 11) Large displacements (stroke) are possible at low frequencies

Hydraulic shakers have the advantage of providing high flexibility of operation during the test their

capabilities include variable-force and constant-force testing and wide-band random-input testing The

velocity and acceleration capabilities of hydraulic shakers are moderate Although any general excitation-

input motion (for example sine wave sine beat wide-band random) can be used in hydraulic shakers

faithful reproduction of these signals is virtually impossible at high frequencies because of distortion and

higher-order harmonics introduced by the high noise levels that are common in hydraulic systems This

is only a minor drawback in heavy-duty intermediate-frequency applications Dynamic interactions are

reduced through feedback control

1215 Inertial Shakers

In inertial shakers or ldquomechanical excitersrdquo the force that causes the shaker-table motion is generated by

inertia forces (accelerating masses) Counter-rotating-mass inertial shakers are typical in this category

To understand their principle of operation consider two equal masses rotating in opposite directions at

the same angular speed v and in the same circle of radius r (see Figure 16) This produces a resultant

force equal to 2mv2r cos vt in a fixed direction (the direction of symmetry of the two rotating arms)

Consequently a sinusoidal force with a frequency of v and an amplitude proportional to v2 is generated

This reaction force is applied to the shaker table

Figure 17 shows a sketch of a typical counter-rotating-mass inertial shaker It consists of two identical

rods rotating at the same speed in opposite directions Each rod has a series of slots in which to

Vibration Instrumentation 1-9

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copy 2007 by Taylor amp Francis Group LLC

place weights In this manner the magnitude of

the eccentric mass can be varied to achieve various

force capabilities The rods are driven by a

variable-speed electric motor through a gear

mechanism that usually provides several speed

ratios A speed ratio is selected depending on the

required test-frequency range The whole system is

symmetrically supported on a carriage that is

directly connected to the test table The test object

is mounted on the test table The preferred

mounting configuration is horizontal so that the

excitation force is applied to the test object in a

horizontal direction In this configuration there

are no variable gravity moments (weight pounddistance to center of gravity) acting on the drive

mechanism Figure 17 shows the vertical con-

figuration In dynamic testing of large structures

the carriage can be mounted directly on the

structure at a location where the excitation force

should be applied By incorporating two pairs of

counter-rotating masses it is possible to generate

test moments as well as test forces

FIGURE 15 A typical hydraulic shaker arrangement (a) schematic diagram (b) operational block diagram

m m

2mw2r cos wt

wtw w

wt

FIGURE 16 Principle of operation of a counter-

rotating-mass inertial shaker

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Reaction-type shakers driven by inertia are widely used for the prototype testing of civil engineering

structures Their first application dates back to 1935 Inertial shakers are capable of producing

intermediate excitation forces The force generated is limited by the strength of the carriage frame The

frequency range of operation and the maximum velocity and acceleration capabilities are also

intermediate for inertial shakers whereas the maximum displacement capability is typically low A major

limitation of inertial shakers is that their excitation force is exclusively sinusoidal and that the force

amplitude is directly proportional to the square of the excitation frequency As a result complex and

random excitation testing constant-force testing (for example transmissibility tests and constant-force

sine-sweep tests) and flexibility to vary the force amplitude or the displacement amplitude during a test

are not generally feasible with this type of shakers Excitation frequency and amplitude can be varied

during testing however by incorporating a variable-speed drive for the motor The sinusoidal excitation

generated by inertial shakers is virtually undistorted which gives them an advantage over the other types

of shakers when used in sine-dwell and sine-sweep tests Small portable shakers with low-force capability

are available for use in on-site testing

1216 Electromagnetic Shakers

In electromagnetic shakers or ldquoelectrodynamic excitersrdquo the motion is generated using the principle of

operation of an electric motor Specifically the excitation force is produced when a variable excitation

signal (electrical) is passed through a moving coil placed in a magnetic field

The components of a commercial electromagnetic shaker are shown in Figure 18 A steady magnetic

field is generated by a stationary electromagnet that consists of field coils wound on a ferromagnetic base

that is rigidly attached to a protective shell structure The shaker head has a coil wound around it When

the excitation electrical signal is passed through this drive coil the shaker head which is supported on

flexure mounts will be set in motion The shaker head consists of the test table on which the test object

is mounted Shakers with interchangeable heads are available The choice of appropriate shaker head is

based on the geometry and mounting features of the test object The shaker head can be turned to

different angles by means of a swivel joint In this manner different directions of excitation (in biaxial

and triaxial testing) can be obtained

FIGURE 17 Sketch of a counter-rotating-mass inertial shaker

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122 Dynamics of Electromagnetic Shakers

Consider a single axis electromagnetic shaker (Figure 18) with a test object having a single natural

frequency of importance within the test frequency range The dynamic interactions between the shaker

and the test object give rise to two significant natural frequencies (and correspondingly two significant

resonances) These appear as peaks in the frequency response curve of the test setup Furthermore the

natural frequency (resonance) of the test package alone causes a ldquotroughrdquo or depression (antiresonance)

in the frequency response curve of the overall test setup To explain this characteristic consider the

dynamic model shown in Figure 19 The following mechanical parameters are defined for

Figure 19(a) m k and b are the mass stiffness and equivalent viscous damping constant respectively

of the test package and me ke and be are the corresponding parameters of the exciter (shaker) Also in

the equivalent electrical circuit of the shaker head as shown in Figure 19(b) the following electrical

parameters are defined Re and Le are the resistance and (leakage) inductance and kb is the back

electromotive force (back emf) of the linear motor Assuming that the gravitational forces are supported

FIGURE 18 Schematic sectional view of a typical electromagnetic shaker manufactured by Bruel and Kjaer

Denmark

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by the static deflections of the flexible elements and that the displacements are measured from the static

equilibrium position we have the following system equations

Test object meuroy frac14 2kethy2 yeTHORN2 beth_y2 _yeTHORN eth119THORNShaker head me euroye frac14 fe thorn kethy2 yeTHORN thorn beth_y2 _yeTHORN2 key 2 be _ye eth120THORN

Electrical Lediedt

thorn Reie thorn kb _ye frac14 vethtTHORN eth121THORN

The electromagnetic force fe generated in the shaker head is a result of the interaction of the magnetic

field generated by the current ie with coil of the moving shaker head and the constant magnetic field

(stator) in which the head coil is located Here we have

fe frac14 kbie eth122THORNNote that v(t) is the voltage signal that is applied by the amplifier to the shaker coil ye is the displacement

of the shaker head and y is the displacement response of the test package

It is assumed that kb has consistent electrical and mechanical units (Vmsec and NA) Usually

the electrical time constant of the shaker is quite small compared with the primarily mechanical

time constants of the shaker and the test package In such cases the Ledie=dt term in Equation 121 may

be neglected Consequently the equations from Equation 119 through Equation 122 may be

expressed in the Laplace (frequency) domain with the Laplace variable s taking the place of the derivative

d=dt as

ethms2 thorn bsthorn kTHORNy frac14 ethbsthorn kTHORNye eth123THORN

FIGURE 19 Dynamic models of an electromagnetic shaker and a flexible test package (a) mechanical model

(b) electrical model

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copy 2007 by Taylor amp Francis Group LLC

frac12mes2 thorn ethbthorn beTHORNsthorn ethkthorn keTHORN ye frac14 ethbsthorn kTHORNy thorn kb

Rev2

k2bs

Reye eth124THORN

It follows that the transfer function of the shaker head motion with respect to the excitation voltage is

given by

yevfrac14 kb

Re

DethsTHORNDdethsTHORN eth125THORN

where DethsTHORN is the characteristic function of the primary dynamics of the test object

DethsTHORN frac14 ms2 thorn bsthorn k eth126THORN

and DdethsTHORN is the characteristic function of the primary dynamic interactions between the shaker and thetest object

DcethsTHORN frac14 mmes4 thorn frac12methbe thorn bthorn boTHORN thornmeb s

3 thorn frac12methke thorn kTHORN thornmekthorn bethbe thorn boTHORN s2thorn frac12bke thorn ethbe thorn boTHORNk sthorn kke

eth127THORN

where

bo frac14 k2bRe

eth128THORN

It is clear that under low damping conditions DdethsTHORN will produce two resonances as it is fourth order in sand similarly DethsTHORN will produce one antiresonance (trough) corresponding to the resonance of the testobject Note that in the frequency domain s frac14 jv and hence the frequency response function given by

Equation 125 is in fact

yevfrac14 kb

Rb

DethjvTHORNDdethjvTHORN eth129THORN

The magnitude of this frequency response function for a typical test system is sketched in Figure 110

Note that this curve is for the ldquoopen-looprdquo case where there is no feedback from the shaker controller

In practice the shaker controller will be able

to compensate for the resonances and anti-

resonances to some degree depending on its

effectiveness

The main advantages of electromagnetic

shakers are their high frequency range of

operation their high degree of operating flexi-

bility and the high level of accuracy of the

generated shaker motion Faithful reproduction

of complex excitations is possible because of the

advanced electronics and control systems used in

this type of shakers Electromagnetic shakers are

not suitable for heavy-duty applications (large test

objects) however High test-input accelerations

are possible at high frequencies when electromag-

netic shakers are used but their displacement and

velocity capabilities are limited to low or

intermediate values (see Table 11)

100

10

1 10 100Excitation Frequency (Hz)

Antiresonance

Resonance

Shak

erD

ispl

acem

entM

agni

tude

Resonance

1000

FIGURE 110 Frequency response curve of a typical

electromagnetic shaker with a test object

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1221 Transient Exciters

Other varieties of exciters are commonly used in

transient-type vibration testing In these tests

either an impulsive force or an initial excitation is

applied to the test object and the resulting

response is monitored The excitations and the

responses are ldquotransientrdquo in this case Hammer

test drop tests and pluck tests fall into this

category For example a hammer test may be

conducted by hitting the object with an instru-

mented hammer and then measuring the response

of the object The hammer has a force sensor at its

tip as sketched in Figure 111 A piezoelectric or

strain-gage type force sensor may be used More

sophisticated hammers have impedance heads in

place of force sensors An impedance head

measures force and acceleration simultaneously

The results of a hammer test will depend on many

factors for example the dynamics of the hammer

body how firmly the hammer is held during the

impact how quickly the impact is applied and

whether there are multiple impacts

13 Control System

The two primary functions of the shaker control system in vibration testing are (1) to guarantee that the

specified excitation is applied to the test object and (2) to ensure that the dynamic stability (motion

constraints) of the test setup is preserved An operational block diagram illustrating these control

functions is given in Figure 112 The reference input to the control system represents the desired

excitation force that should be applied to the test object In the absence of any control however the force

reaching the test object will be distorted primarily because of (1) dynamic interactions and

nonlinearities of the shaker the test table the mounting fixtures the auxiliary instruments and the test

object itself (2) noise and errors in the signal generator amplifiers filters and other equipment and (3)

external loads and disturbances acting on the test object and other components (for example external

restraints aerodynamic forces friction) To compensate for these distorting factors response

measurements (displacements velocities acceleration and so on) are made at various locations in the

test setup and are used to control the system dynamics In particular the responses of the shaker the test

table and the test object are measured These responses are used to compare the actual excitation felt by

FIGURE 111 An instrumented hammer used in bump

tests or hammer tests

ExcitationInput

(Reference)

Feedback Paths

DriveSignal

ShakerResponse

TestTable

TestObject

Test ObjectResponse

Test TableResponseExciter

(Shaker)(Ram)

Controllerand

Amplifier

FIGURE 112 Operational block diagram illustrating a general shaker control system

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the test object at the shaker interface with the desired (specified) input The drive signal to the shaker is

modified depending on the error that is present

Two types of control are commonly employed in shaker apparatus simple manual control and

complex automatic control Manual control normally consists of simple open-loop trial-and-error

methods of manual adjustments (or calibration) of the control equipment to obtain a desired dynamic

response The actual response is usually monitored (on an oscilloscope or frequency analyzer screen for

example) during manual-control operations The pretest adjustments in manual control can be very

time-consuming as a result the test object might be subjected to overtesting which could produce

cumulative damage is undesirable and could defeat the test purpose Furthermore the calibration

procedure for the experimental setup must be repeated for each new test object

The disadvantages ofmanual control suggest that automatic control is desirable in complex test schemes

in which high accuracy of testing is desired The first step of automatic control involves automatic

measurement of the system response using control sensors and transducers The measurement is then fed

back into the control system which instantaneously determines the best drive signal to actuate the shaker

in order to get the desired excitation This may be done by either analog or digital methods

Primitive control systems require an accurate mathematical description of the test object This

dependency of the control system on the knowledge of test-object dynamics is clearly undesirable

Performance of a good control system should not be considerably affected by the dynamic interactions

and nonlinearities of the test object or by the nature of the excitation Proper selection of feedback signals

and control-system components can reduce such effects and will make the system robust

In the response-spectrum method of vibration testing it is customary to use displacement control at

low frequencies velocity control at intermediate frequency and acceleration control at high frequencies

This necessitates feedback of displacement velocity and acceleration responses Generally however the

most important feedback is the velocity feedback In sine-sweep tests the shaker velocity must change

steadily over the frequency band of interest In particular the velocity control must be precise near the

resonances of the test object Velocity (speed) feedback has a stabilizing effect on the dynamics which is

desirable This effect is particularly useful in ensuring stability in motion when testing is done near

resonances of lightly damped test objects On the contrary displacement (position) feedback can have a

destabilizing effect on some systems particularly when high feedback gains are used

The controller usually consists of various instruments equipment and computation hardware and

software Often the functions of the data-acquisition and processing system overlap with those of the

controller to some extent As an example consider the digital-controller of vibration testing apparatus

First the responses are measured through sensors (and transducers) filtered and amplified

(conditioned) These data channels may be passed through a multiplexer whose purpose is to select

one data channel at a time for processing Most modern data acquisition hardware does not need a

separate multiplexer to handle multiple signals The analog data are converted into digital data using

analog-to-digital converters (ADCs) The resulting sampled data are stored on a disk or as a block data in

the computer memory The reference input signal (typically a signal recorded on an FM tape) is also

sampled (if it is not already in the digital form) using an ADC and fed into the computer Digital

processing is done on the reference signal and the response data with the objective of computing the

command signal to drive the shaker The digital command signal is converted into an analog signal using

a digital-to-analog converter (DAC) and amplified (conditioned) before it is used to drive the exciter

The nature of the control components depends to a large extent on the nature and objectives of the

particular test to be conducted Some of the basic components in a shaker controller are described in

the following subsections

131 Components of a Shaker Controller

1311 Compressor

A compressor circuit is incorporated in automatic excitation control devices to control the excitation-

input level automatically The level of control depends on the feedback signal from a control sensor and

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the specified (reference) excitation signal Usually the compressor circuit is included in the excitation-

signal generator (for example in a sine generator) The control by this means may be done on the basis of

a single-frequency component (eg the fundamental frequency)

1312 Equalizer (Spectrum Shaper)

Random-signal equalizers are used to shape the spectrum of a random signal in a desired manner In

essence and equalizer consists of a bank of narrow-band filters (for example 80 filters) in parallel over

the operating frequency range By passing the signal through each filter the spectral density (or the mean

square value) of the signal in that narrow frequency band (for example each one-third-octave band) is

determined This is compared with the desired spectral level and automatic adjustment is made in that

filter in case there is an error In some systems response-spectrum analysis is made in place of power

spectral density analysis In that case the equalizer consists of a bank of simple oscillators whose

resonant frequencies are distributed over the operating frequency range of the equalizer The feedback

signal is passed through each oscillator and the peak value of its output is determined This value is

compared with the desired response spectrum value at that frequency If there is an error automatic gain

adjustment is made in the appropriate excitation signal components

Random-noise equalizers are used in conjunction with random signal generators They receive

feedback signals from the control sensors In some digital control systems there are algorithms (software)

that are used to iteratively converge the spectrum of the excitation signal felt by the test object into the

desired spectrum

1313 Tracking Filter

Many vibration tests are based on single-frequency excitations In such cases the control functions

should be performed on the basis of the amplitudes of the fundamental-frequency component of the

signal A tracking filter is simply a frequency-tuned band-pass filter It automatically tunes the center

frequency of its very narrow-band-pass filter to the frequency of a carrier signal Then when a noisy

signal is passed through the tuned filter the output of the filter will be the required fundamental

frequency component in the signal Tracking filters also are useful in obtaining amplitudendashfrequency

plots using an XndashY plotter In such cases the frequency value comes from the signal generator (sweep

oscillator) which produces the carrier signal to the tracking filter The tracking filter then determines the

corresponding amplitude of a signal that is fed into it Most tracking filters have dual channels so that two

signals can be handled (tracked) simultaneously

1314 Excitation Controller (Amplitude Servo-Monitor)

An excitation controller is typically an integral part of the signal generator It can be set so that automatic

sweep between two frequency limits can be performed at a selected sweep rate (linear or logarithmic)

More advanced excitation controllers have the capability of an automatic switch-over between constant-

displacement constant-velocity and constant-acceleration excitation-input control at specified

frequencies over the sweep frequency interval Consequently integrator circuits should be present

within the excitation controller unit to determine velocities and displacements from acceleration signals

Sometimes integration is performed by a separate unit called a vibration meter This unit also offers

the operator the capability of selecting the desired level of each signal (acceleration velocity or

displacement) There is an automatic cut-off level for large displacement values that could result from

noise in acceleration signals A compressor is also a subcomponent of the excitation controller The

complete unit is sometimes known as an amplitude servo-monitor

132 Signal-Generating Equipment

Shakers are force-generating devices that are operated using drive (excitation) signals generated from a

source The excitation-signal source is known as the signal generator Three major types of signal

generators are used in vibration testing applications (1) oscillators (2) random-signal generators and

(3) storage devices In some units oscillators and random-signal generators are combined We shall

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copy 2007 by Taylor amp Francis Group LLC

discuss these two generators separately however because of their difference in function It also should be

noted that almost any digital signal (deterministic or random) can be generated by a digital computer

using a suitable computer program the signal eventually can be passed through a DAC to obtain

the corresponding analog signal These lsquodigitalrsquo signal generators along with analog sources such as

magnetic tape players (FM) are classified into the category of storage devices

The dynamic range of equipment is the ratio of the maximum and minimum output levels (expressed

in decibels) at which it is capable of operating without significant error This is an important specification

for many types of equipment particularly for signal-generating devices The output level of the signal

generator should be set to a value within its dynamic range

1321 Oscillators

Oscillators are essentially single-frequency generators Typically sine signals are generated but other

waveforms (such as rectangular and triangular pulses) are also available in most oscillators Normally

an oscillator has two modes of operation (1) sweeping up and down between two frequency limits and

(2) dwelling at a specified frequency In the sweep operation the sweep rate should be specified This can

be done either on a linear scale (Hzmin) or on a logarithmic scale (octavesmin) In the dwell operation

the frequency points (or intervals) should be specified In either case a desired signal level can be chosen

using the gain-control knob An oscillator that is operated exclusively in the sweep mode is called a sweep

oscillator

The early generation of oscillators employed variable inductor-capacitor types of electronic circuits to

generate signals oscillating at a desired frequency The oscillator is tuned to the required frequency by

varying the capacitance or inductance parameters A DC voltage is applied to energize the capacitor

and to obtain the desired oscillating voltage signal which subsequently is amplified and conditioned

Modern oscillators use operational amplifier circuits along with resistor capacitor and semiconductor

(SC) elements Also common are crystal (quartz) parallel-resonance oscillators used to generate voltage

signals accurately at a fixed frequency The circuit is activated using a DC-voltage source Other

frequencies of interest are obtained by passing this high-frequency signal through a frequency converter

The signal is then conditioned (amplified and filtered) Required shaping (for example rectangular

pulse) is obtained using a shape circuit Finally the required signal level is obtained by passing the

resulting signal through a variable-gain amplifier A block diagram of an oscillator illustrating various

stages in the generation of a periodic signal is given in Figure 113

A typical oscillator offers a choice of several (typically six) linear and logarithmic frequency ranges and

a sizable level of control capability (for example 80 dB) Upper and lower frequency limits in a sweep can

be preset on the front panel to any of the available frequency ranges Sweep-rate settings are continuously

DC Voltage

Oscillator

FrequencySpecification

FrequencyConverter

FilterAmplifier

ShaperPeriodicSignal

FrequencyCounter

Fixed-FrequencySignal

Variable-GainOutput

Amplifier

SignalSpecification

LevelSpecification

FIGURE 113 Block diagram of an oscillator-type signal generator

Vibration Monitoring Testing and Instrumentation1-18

53191mdash522007mdash1202mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

  • 53191fm
    • Vibration Monitoring Testing and Instrumentation
      • Preface
      • Acknowledgments
      • Editor-in-Chief
      • Contributors
      • Contents
      • Related Titles
          • 53191ch1
            • Table of Contents
            • Chapter 1 Vibration Instrumentation
              • Summary
              • 11 Introduction
              • 12 Vibration Exciters
                • 121 Shaker Selection
                  • 1211 Force Rating
                  • 1212 Power Rating
                  • 1213 Stroke Rating
                  • 1214 Hydraulic Shakers
                  • 1215 Inertial Shakers
                  • 1216 Electromagnetic Shakers
                    • 122 Dynamics of Electromagnetic Shakers
                      • 1221 Transient Exciters
                          • 13 Control System
                            • 131 Components of a Shaker Controller
                              • 1311 Compressor
                              • 1312 Equalizer (Spectrum Shaper)
                              • 1313 Tracking Filter
                              • 1314 Excitation Controller (Amplitude Servo-Monitor)
                                • 132 Signal-Generating Equipment
                                  • 1321 Oscillators
                                  • 1322 Random Signal Generators
                                  • 1323 Tape Players
                                  • 1324 Data Processing
                                      • 14 Performance Specification
                                        • 141 Parameters for Performance Specification
                                          • 1411 Time-Domain Specifications
                                          • 1412 Frequency-Domain Specifications
                                            • 142 Linearity
                                            • 143 Instrument Ratings
                                              • 1431 Rating Parameters
                                                • 144 Accuracy and Precision
                                                  • 15 Motion Sensors and Transducers
                                                    • 151 Potentiometer
                                                      • 1511 Potentiometer Resolution
                                                      • 1512 Optical Potentiometer
                                                        • 152 Variable-Inductance Transducers
                                                          • 1521 Mutual-Induction Transducers
                                                          • 1522 Linear-Variable Differential Transformer
                                                          • 1523 Signal Conditioning
                                                            • 153 Mutual-Induction Proximity Sensor
                                                            • 154 Selfinduction Transducers
                                                            • 155 Permanent-Magnet Transducers
                                                            • 156 Alternating Current Permanent-Magnet Tachometer
                                                            • 157 Alternating Current Induction Tachometer
                                                            • 158 Eddy Current Transducers
                                                            • 159 Variable-Capacitance Transducers
                                                              • 1591 Capacitive Displacement Sensors
                                                              • 1592 Capacitive Angular Velocity Sensor
                                                              • 1593 Capacitance Bridge Circuit
                                                                • 1510 Piezoelectric Transducers
                                                                  • 15101 Sensitivity
                                                                  • 15102 Piezoelectric Accelerometer
                                                                  • 15103 Charge Amplifier
                                                                      • 16 Torque Force and Other Sensors
                                                                        • 161 Strain Gage Sensors
                                                                          • 1611 Equations for Strain Gage Measurements
                                                                          • 1612 Bridge Sensitivity
                                                                          • 1613 The Bridge Constant
                                                                          • 1614 The Calibration Constant
                                                                          • 1615 Data Acquisition
                                                                          • 1616 Accuracy Considerations
                                                                          • 1617 Semiconductor Strain Gages
                                                                          • 1618 Force and Torque Sensors
                                                                          • 1619 Strain Gage Torque Sensors
                                                                          • 16110 Deflection Torque Sensors
                                                                          • 16111 Variable-Reluctance Torque Sensor
                                                                          • 16112 Reaction Torque Sensors
                                                                            • 162 Miscellaneous Sensors
                                                                              • 1621 Stroboscope
                                                                              • 1622 Fiber Optic Sensors and Lasers
                                                                              • 1623 Fiber-Optic Gyroscope
                                                                              • 1624 Laser Doppler Interferometer
                                                                              • 1625 Ultrasonic Sensors
                                                                              • 1626 Gyroscopic Sensors
                                                                                  • References
                                                                                  • Appendix 1A Virtual Instrumentation for Data Acquisition Analysis and Presentation
                                                                                    • Summary
                                                                                    • List of Abbreviations
                                                                                    • 1A1 Dynamic Signals
                                                                                      • 1A11 Acquiring and Simulating Dynamic Signals
                                                                                        • 1A111 Aliasing
                                                                                        • 1A112 Time Continuity
                                                                                            • 1A2 Measurement Configuration Considerations
                                                                                              • 1A21 Input Signal Considerations
                                                                                                • 1A211 Input Pseudodifferential and Differential Configuration
                                                                                                • 1A212 Gain
                                                                                                • 1A213 Input Coupling
                                                                                                • 1A214 Integrated Electronic Piezoelectric Excitation
                                                                                                • 1A215 Nyquist Frequency and Bandwidth
                                                                                                • 1A216 Analog-to-Digital Conversion
                                                                                                • 1A217 Antialias Filters
                                                                                                • 1A218 Input Filter Delay
                                                                                                • 1A219 Overload Detection
                                                                                                  • 1A22 Output Signal Considerations
                                                                                                    • 1A221 Output Pseudodifferential and Differential Configuration
                                                                                                    • 1A222 Attenuation
                                                                                                    • 1A223 Digital-to-Analog Conversion
                                                                                                    • 1A224 Anti-imaging and Interpolation Filters
                                                                                                    • 1A225 Output Filter Delay
                                                                                                        • 1A3 Scaling and Calibration
                                                                                                          • 1A31 Scaling to Engineering Units
                                                                                                          • 1A32 Performing System Calibration
                                                                                                            • 1A321 Propagation Delay Calibration
                                                                                                                • 1A4 Limit Testing Analysis
                                                                                                                  • 1A41 Limit Testing Overview
                                                                                                                  • 1A42 Using the SVT Limit Testing VI
                                                                                                                    • 1A5 Integration
                                                                                                                      • 1A51 Introduction to Integration
                                                                                                                      • 1A52 Implementing Integration
                                                                                                                        • 1A521 Challenges when Integrating Vibration Data
                                                                                                                          • 1A53 Time-Domain Integration
                                                                                                                            • 1A531 Single-Shot Acquisition and Integration
                                                                                                                            • 1A532 Continuous Acquisition and Integration
                                                                                                                              • 1A54 Frequency-Domain Integration
                                                                                                                                • 1A6 Vibration-Level Measurements
                                                                                                                                  • 1A61 Measuring the Root Mean Square Level
                                                                                                                                    • 1A611 Single-Shot Buffered Acquisition
                                                                                                                                    • 1A612 Continuous Signal Acquisition
                                                                                                                                      • 1A62 Performing a Running RMS Level Measurement
                                                                                                                                      • 1A63 Computing the Peak Level
                                                                                                                                      • 1A64 Computing the Crest Factor
                                                                                                                                        • 1A7 Frequency Analysis
                                                                                                                                          • 1A71 FFT Fundamentals
                                                                                                                                            • 1A711 Number of Samples
                                                                                                                                            • 1A712 Frequency Resolution
                                                                                                                                            • 1A713 Maximum Resolvable Frequency
                                                                                                                                            • 1A714 Minimum Resolvable Frequency
                                                                                                                                            • 1A715 Number of Spectral Lines
                                                                                                                                            • 1A716 Relationship between Time-Domain and Frequency-Domain Specifications and Parameters
                                                                                                                                              • 1A72 Increasing Frequency Resolution
                                                                                                                                                • 1A721 Zoom FFT Analysis
                                                                                                                                                • 1A722 Frequency Resolution of the Zoom FFT VIs
                                                                                                                                                • 1A723 Zoom Measurement
                                                                                                                                                • 1A724 Zoom Settings
                                                                                                                                                • 1A725 Subset Analysis
                                                                                                                                                    • 1A8 Transient Analysis
                                                                                                                                                      • 1A81 Transient Analysis with the Sound and Vibration Toolkit
                                                                                                                                                      • 1A82 Performing an STFT vs Time
                                                                                                                                                        • 1A821 Selecting the FFT Block Size
                                                                                                                                                        • 1A822 Overlapping
                                                                                                                                                        • 1A823 Using the SVT STFT vs Time VI
                                                                                                                                                          • 1A83 Performing an STFT vs Rotational Speed
                                                                                                                                                            • 1A831 Converting the Pulse Train to Rotational Speed
                                                                                                                                                            • 1A832 STFT vs RPM
                                                                                                                                                              • 1A84 Measuring a Shock Response Spectrum
                                                                                                                                                                • 1A9 Waterfall Display
                                                                                                                                                                  • 1A91 Using the Display VIs
                                                                                                                                                                    • 1A911 Initializing the Display
                                                                                                                                                                    • 1A912 Sending Data to the Display
                                                                                                                                                                    • 1A913 Waterfall Display for Frequency Analysis
                                                                                                                                                                    • 1A914 Waterfall Display for Transient Analysis
                                                                                                                                                                    • 1A915 Waterfall Display for Octave Spectra
                                                                                                                                                                        • 1A10 Swept-Sine Measurements
                                                                                                                                                                          • 1A101 Swept-Sine Overview
                                                                                                                                                                          • 1A102 Choosing Swept-Sine vs FFT Measurements
                                                                                                                                                                          • 1A103 Taking a Swept-Sine Measurement
                                                                                                                                                                          • 1A104 Swept-Sine Measurement Example
                                                                                                                                                                              • Bibliography
                                                                                                                                                                              • Related Titles
                                                                                                                                                                                  • 53191ch2
                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                    • Chapter 2 Signal Conditioning and Modification
                                                                                                                                                                                      • Summary
                                                                                                                                                                                      • 21 Introduction
                                                                                                                                                                                      • 22 Amplifiers
                                                                                                                                                                                        • 221 Operational Amplifier
                                                                                                                                                                                        • 222 Use of Feedback in Opamp
                                                                                                                                                                                        • 223 Voltage Current and Power Amplifiers
                                                                                                                                                                                          • 2231 Charge Amplifiers
                                                                                                                                                                                            • 224 Instrumentation Amplifiers
                                                                                                                                                                                              • 2241 Differential Amplifier
                                                                                                                                                                                              • 2242 Common Mode
                                                                                                                                                                                                • 225 Amplifier Performance Ratings
                                                                                                                                                                                                  • 2251 Common-Mode Rejection Ratio
                                                                                                                                                                                                    • 226 Component Interconnection
                                                                                                                                                                                                      • 2261 Impedance Characteristics
                                                                                                                                                                                                      • 2262 Cascade Connection of Devices
                                                                                                                                                                                                      • 2263 AC-Coupled Ampliers
                                                                                                                                                                                                          • 23 Analog Filters
                                                                                                                                                                                                            • 231 Passive Filters and Active Filters
                                                                                                                                                                                                              • 2311 Number of Poles
                                                                                                                                                                                                                • 232 Low-Pass Filters
                                                                                                                                                                                                                  • 2321 Low-Pass Butterworth Filter
                                                                                                                                                                                                                    • 233 High-Pass Filters
                                                                                                                                                                                                                    • 234 Band-Pass Filters
                                                                                                                                                                                                                      • 2341 Resonance-Type Band-Pass Filters
                                                                                                                                                                                                                        • 235 Band-Reject Filters
                                                                                                                                                                                                                          • 24 Modulators and Demodulators
                                                                                                                                                                                                                            • 241 Amplitude Modulation
                                                                                                                                                                                                                              • 2411 Modulation Theorem
                                                                                                                                                                                                                              • 2412 Side Frequencies and Side Bands
                                                                                                                                                                                                                                • 242 Application of Amplitude Modulation
                                                                                                                                                                                                                                  • 2421 Fault Detection and Diagnosis
                                                                                                                                                                                                                                    • 243 Demodulation
                                                                                                                                                                                                                                      • 25 Analog ndashDigital Conversion
                                                                                                                                                                                                                                        • 251 Digital-to-Analog Conversion
                                                                                                                                                                                                                                          • 2511 DAC Error Sources
                                                                                                                                                                                                                                            • 252 Analog-to-Digital Conversion
                                                                                                                                                                                                                                            • 253 Analog-to-Digital Converter Performance Characteristics
                                                                                                                                                                                                                                              • 2531 Resolution and Quantization Error
                                                                                                                                                                                                                                              • 2532 Monotonicity Nonlinearity and Offset Error
                                                                                                                                                                                                                                              • 2533 Analog-to-Digital Converter Conversion Rate
                                                                                                                                                                                                                                                • 254 Sample-and-Hold Circuitry
                                                                                                                                                                                                                                                • 255 Digital Filters
                                                                                                                                                                                                                                                  • 2551 Software Implementation and Hardware Implementation
                                                                                                                                                                                                                                                      • 26 Bridge Circuits
                                                                                                                                                                                                                                                        • 261 Wheatstone Bridge
                                                                                                                                                                                                                                                        • 262 Constant-Current Bridge
                                                                                                                                                                                                                                                        • 263 Bridge Amplifiers
                                                                                                                                                                                                                                                          • 2631 Half-Bridge Circuits
                                                                                                                                                                                                                                                            • 264 Impedance Bridges
                                                                                                                                                                                                                                                              • 2641 Owen Bridge
                                                                                                                                                                                                                                                              • 2642 Wien-Bridge Oscillator
                                                                                                                                                                                                                                                                  • 27 Linearizing Devices
                                                                                                                                                                                                                                                                    • 271 Linearization by Software
                                                                                                                                                                                                                                                                    • 272 Linearization by Hardware Logic
                                                                                                                                                                                                                                                                    • 273 Analog Linearizing Circuitry
                                                                                                                                                                                                                                                                    • 274 Offsetting Circuitry
                                                                                                                                                                                                                                                                    • 275 Proportional-Output Circuitry
                                                                                                                                                                                                                                                                      • 2751 Curve-Shaping Circuitry
                                                                                                                                                                                                                                                                          • 28 Miscellaneous Signal Modification Circuitry
                                                                                                                                                                                                                                                                            • 281 Phase Shifters
                                                                                                                                                                                                                                                                            • 282 Voltage-to-Frequency Converter
                                                                                                                                                                                                                                                                            • 283 Frequency-to-Voltage Converter
                                                                                                                                                                                                                                                                            • 284 Voltage-to-Current Converters
                                                                                                                                                                                                                                                                            • 285 Peak-Hold Circuits
                                                                                                                                                                                                                                                                              • 29 Signal Analyzers and Display Devices
                                                                                                                                                                                                                                                                                • 291 Signal Analyzers
                                                                                                                                                                                                                                                                                • 292 Oscilloscopes
                                                                                                                                                                                                                                                                                  • 2921 Triggering
                                                                                                                                                                                                                                                                                  • 2922 Lissajous Patterns
                                                                                                                                                                                                                                                                                  • 2923 Digital Oscilloscopes
                                                                                                                                                                                                                                                                                      • Bibliography
                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                          • 53191ch3
                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                            • Chapter 3 Vibration Testing
                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                              • 31 Introduction
                                                                                                                                                                                                                                                                                              • 32 Representation of a Vibration Environment
                                                                                                                                                                                                                                                                                                • 321 Test Signals
                                                                                                                                                                                                                                                                                                  • 3211 Stochastic vs Deterministic Signals
                                                                                                                                                                                                                                                                                                    • 322 Deterministic Signal Representation
                                                                                                                                                                                                                                                                                                      • 3221 Single-Frequency Signals
                                                                                                                                                                                                                                                                                                      • 3222 Sine Sweep
                                                                                                                                                                                                                                                                                                      • 3223 Sine Dwell
                                                                                                                                                                                                                                                                                                      • 3224 Decaying Sine
                                                                                                                                                                                                                                                                                                      • 3225 Sine Beat
                                                                                                                                                                                                                                                                                                      • 3226 Sine Beat with Pauses
                                                                                                                                                                                                                                                                                                      • 3227 Multifrequency Signals
                                                                                                                                                                                                                                                                                                      • 3228 Actual Excitation Records
                                                                                                                                                                                                                                                                                                      • 3229 Simulated Excitation Signals
                                                                                                                                                                                                                                                                                                        • 323 Stochastic Signal Representation
                                                                                                                                                                                                                                                                                                          • 3231 Ergodic Random Signals
                                                                                                                                                                                                                                                                                                          • 3232 Stationary Random Signals
                                                                                                                                                                                                                                                                                                          • 3233 Independent and Uncorrelated Signals
                                                                                                                                                                                                                                                                                                          • 3234 Transmission of Random Excitations
                                                                                                                                                                                                                                                                                                            • 324 Frequency-Domain Representations
                                                                                                                                                                                                                                                                                                              • 3241 Fourier Spectrum Method
                                                                                                                                                                                                                                                                                                              • 3242 Power Spectral Density Method
                                                                                                                                                                                                                                                                                                                • 325 Response Spectrum
                                                                                                                                                                                                                                                                                                                  • 3251 Displacement Velocity and Acceleration Spectra
                                                                                                                                                                                                                                                                                                                  • 3252 Response-Spectra Plotting Paper
                                                                                                                                                                                                                                                                                                                  • 3253 Zero-Period Acceleration
                                                                                                                                                                                                                                                                                                                  • 3254 Uses of Response Spectra
                                                                                                                                                                                                                                                                                                                    • 326 Comparison of Various Representations
                                                                                                                                                                                                                                                                                                                      • 33 Pretest Procedures
                                                                                                                                                                                                                                                                                                                        • 331 Purpose of Testing
                                                                                                                                                                                                                                                                                                                        • 332 Service Functions
                                                                                                                                                                                                                                                                                                                          • 3321 Active Equipment
                                                                                                                                                                                                                                                                                                                          • 3322 Passive Equipment
                                                                                                                                                                                                                                                                                                                          • 3323 Functional Testing
                                                                                                                                                                                                                                                                                                                            • 333 Information Acquisition
                                                                                                                                                                                                                                                                                                                              • 3331 Interface Details
                                                                                                                                                                                                                                                                                                                              • 3332 Effect of Neglecting Interface Dynamics
                                                                                                                                                                                                                                                                                                                              • 3333 Effects of Damping
                                                                                                                                                                                                                                                                                                                              • 3334 Effects of Inertia
                                                                                                                                                                                                                                                                                                                              • 3335 Effect of Natural Frequency
                                                                                                                                                                                                                                                                                                                              • 3336 Effect of Excitation Frequency
                                                                                                                                                                                                                                                                                                                              • 3337 Other Effects of Interface
                                                                                                                                                                                                                                                                                                                                • 334 Test-Program Planning
                                                                                                                                                                                                                                                                                                                                  • 3341 Testing of Cabinet-Mounted Equipment
                                                                                                                                                                                                                                                                                                                                    • 335 Pretest Inspection
                                                                                                                                                                                                                                                                                                                                      • 34 Testing Procedures
                                                                                                                                                                                                                                                                                                                                        • 341 Resonance Search
                                                                                                                                                                                                                                                                                                                                        • 342 Methods of Determining Frequency-Response Functions
                                                                                                                                                                                                                                                                                                                                          • 3421 Fourier Transform Method
                                                                                                                                                                                                                                                                                                                                          • 3422 Spectral Density Method
                                                                                                                                                                                                                                                                                                                                          • 3423 Harmonic Excitation Method
                                                                                                                                                                                                                                                                                                                                            • 343 Resonance-Search Test Methods
                                                                                                                                                                                                                                                                                                                                              • 3431 Hammer (Bump) Test and Drop Test
                                                                                                                                                                                                                                                                                                                                              • 3432 Pluck Test
                                                                                                                                                                                                                                                                                                                                              • 3433 Shaker Tests
                                                                                                                                                                                                                                                                                                                                                • 344 Mechanical Aging
                                                                                                                                                                                                                                                                                                                                                  • 3441 Equivalence for Mechanical Aging
                                                                                                                                                                                                                                                                                                                                                  • 3442 Excitation-Intensity Equivalence
                                                                                                                                                                                                                                                                                                                                                  • 3443 Dynamic-Excitation Equivalence
                                                                                                                                                                                                                                                                                                                                                  • 3444 Cumulative Damage Theory
                                                                                                                                                                                                                                                                                                                                                    • 345 Test-Response Spectrum Generation
                                                                                                                                                                                                                                                                                                                                                    • 346 Instrument Calibration
                                                                                                                                                                                                                                                                                                                                                    • 347 Test-Object Mounting
                                                                                                                                                                                                                                                                                                                                                    • 348 Test-Input Considerations
                                                                                                                                                                                                                                                                                                                                                      • 3481 Test Nomenclature
                                                                                                                                                                                                                                                                                                                                                      • 3482 Testing with Uncorrelated Excitations
                                                                                                                                                                                                                                                                                                                                                      • 3483 Symmetrical Rectilinear Testing
                                                                                                                                                                                                                                                                                                                                                      • 3484 Geometry vs Dynamics
                                                                                                                                                                                                                                                                                                                                                      • 3485 Some Limitations
                                                                                                                                                                                                                                                                                                                                                      • 3486 Testing Black Boxes
                                                                                                                                                                                                                                                                                                                                                      • 3487 Phasing of Excitations
                                                                                                                                                                                                                                                                                                                                                      • 3488 Testing a Gray or White Box
                                                                                                                                                                                                                                                                                                                                                      • 3489 Overtesting in Multitest Sequences
                                                                                                                                                                                                                                                                                                                                                          • 35 Some Practical Information
                                                                                                                                                                                                                                                                                                                                                            • 351 Random Vibration Test Example
                                                                                                                                                                                                                                                                                                                                                            • 352 Vibration Shakers and Control Systems
                                                                                                                                                                                                                                                                                                                                                              • Bibliography
                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                  • 53191ch4
                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                    • Chapter 4 Experimental Modal Analysis
                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                      • 41 Introduction
                                                                                                                                                                                                                                                                                                                                                                      • 42 Frequency-Domain Formulation
                                                                                                                                                                                                                                                                                                                                                                        • 421 Transfer-Function Matrix
                                                                                                                                                                                                                                                                                                                                                                        • 422 Principle of Reciprocity
                                                                                                                                                                                                                                                                                                                                                                          • 43 Experimental Model Development
                                                                                                                                                                                                                                                                                                                                                                            • 431 Extraction of the Time-Domain Model
                                                                                                                                                                                                                                                                                                                                                                              • 44 Curve Fitting of Transfer Functions
                                                                                                                                                                                                                                                                                                                                                                                • 441 Problem Identification
                                                                                                                                                                                                                                                                                                                                                                                • 442 Single- and Multi-Degree-of-Freedom Techniques
                                                                                                                                                                                                                                                                                                                                                                                • 443 Single-Degree-of-Freedom Parameter Extraction in the Frequency Domain
                                                                                                                                                                                                                                                                                                                                                                                  • 4431 Circle-Fit Method
                                                                                                                                                                                                                                                                                                                                                                                    • Case of Viscous Damping
                                                                                                                                                                                                                                                                                                                                                                                    • Case of Hysteretic Damping
                                                                                                                                                                                                                                                                                                                                                                                      • 4432 Peak-Picking Method
                                                                                                                                                                                                                                                                                                                                                                                        • 444 Multi-Degree of Freedom Curve Fitting
                                                                                                                                                                                                                                                                                                                                                                                          • 4441 Formulation of the Method
                                                                                                                                                                                                                                                                                                                                                                                            • 445 A Comment on Static Modes and Rigid-Body Modes
                                                                                                                                                                                                                                                                                                                                                                                            • 446 Residue Extraction
                                                                                                                                                                                                                                                                                                                                                                                              • 45 Laboratory Experiments
                                                                                                                                                                                                                                                                                                                                                                                                • 451 Lumped-Parameter System
                                                                                                                                                                                                                                                                                                                                                                                                  • 4511 Frequency-Domain Test
                                                                                                                                                                                                                                                                                                                                                                                                  • 4512 Time-Domain Tests
                                                                                                                                                                                                                                                                                                                                                                                                    • 452 Distributed-Parameter System
                                                                                                                                                                                                                                                                                                                                                                                                      • 46 Commercial EMA Systems
                                                                                                                                                                                                                                                                                                                                                                                                        • 461 System Configuration
                                                                                                                                                                                                                                                                                                                                                                                                          • 4611 FFT Analysis Options
                                                                                                                                                                                                                                                                                                                                                                                                          • 4612 Modal Analysis Components
                                                                                                                                                                                                                                                                                                                                                                                                              • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                  • 53191ch5
                                                                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                    • Chapter 5 Mechanical Shock
                                                                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                      • 51 Definitions
                                                                                                                                                                                                                                                                                                                                                                                                                        • 511 Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 512 Simple (or Perfect) Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 513 Half-Sine Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 514 Versed-Sine (or Haversine) Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 515 Terminal Peak Sawtooth Shock or Final Peak Sawtooth Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 516 Rectangular Shock
                                                                                                                                                                                                                                                                                                                                                                                                                          • 5161 Trapezoidal Shock
                                                                                                                                                                                                                                                                                                                                                                                                                              • 52 Description in the Time Domain
                                                                                                                                                                                                                                                                                                                                                                                                                              • 53 Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                • 531 Need
                                                                                                                                                                                                                                                                                                                                                                                                                                • 532 Shock Response Spectrum Definition
                                                                                                                                                                                                                                                                                                                                                                                                                                • 533 Response of a Linear One-Degree-of-Freedom System
                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5331 Shock Defined by a Force
                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5332 Shock Defined by an Acceleration
                                                                                                                                                                                                                                                                                                                                                                                                                                    • 534 Definitions
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5341 Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5342 Absolute Acceleration Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5343 Relative Displacement Shock Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5344 Primary Positive Shock Response Spectrum or Initial Positive Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5345 Primary (or Initial) Negative Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5346 Secondary (or Residual) Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5347 Positive (or Maximum Positive) Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5348 Negative (or Maximum Negative) Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5349 Maximax Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53410 Choice of Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                        • 535 Standardized Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5351 Definition
                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5352 Standardized Shock Response Spectra of Simple Shocks
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53521 Half-Sine Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53522 Versed Sine Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53523 Terminal Peak Sawtooth Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53524 Rectangular Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53525 Trapezoidal Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 536 Choice of Damping
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 537 Shock Response Spectra Domains
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 538 Algorithms for Calculation of the Shock Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 539 Choice of the Digitization Frequency of the Signal
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5310 Use of Shock Response Spectra for the Study of Systems with Several Degrees of Freedom
                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 54 Pyroshocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 55 Use of Shock Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 551 Severity Comparison of Several Shocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 552 Test Specification Development from Real Environment Data
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5521 Synthesis of Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5522 Nature of the Specification
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5523 Choice of Shape
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5524 Amplitude
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5525 Duration
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5526 Difficulties
                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 56 Standards
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 561 Types of Standards
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 562 Installation Conditions of Test Item
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 563 Uncertainty Factor
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 564 Bump Test
                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 57 Damage Boundary Curve
                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 571 Definition
                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 572 Analysis of Test Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 58 Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 581 Main Types
                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 582 Impact Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5821 Universal Shock-Test Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 58211 Impact Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 58212 Impulse Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 583 Shock Simulators (Programmers)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5831 Half-Sine Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58311 Shock Duration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58312 Impact Velocity
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58313 Maximum Deformation of the Shock Simulator (Programmer)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58314 Shock Amplitude
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58315 Characteristics of the Target
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5832 Terminal Peak Sawtooth Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5833 Rectangular Pulse ndash Trapezoidal Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5834 Universal Shock Simulator (Programmer)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 58341 Generating a Half-Sine Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 58342 Generating a Terminal Peak Sawtooth Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 58343 Trapezoidal Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 584 Limitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5841 Limitations of the Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5842 Limitations of Shock Simulators
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 585 Pneumatic Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 586 High Impact Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5861 Lightweight High Impact Shock Machine
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5862 Medium Weight High Impact Shock Machine
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 587 Specific Test Facilities
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 59 Generation of Shock Using Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 591 Principle Behind the Generation of a Simple Shape Signal versus Time
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 592 Main Advantages
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 593 Pre- and Postshocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5931 Requirements
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5932 Solutions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 59321 Optimized Pre- and Postpulses
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5933 Incidence on the Shock Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 594 Limitations of Electrodynamic Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5941 Mechanical Limitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 59411 Abacuses
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5942 Electronic Limitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 595 The Use of Electrohydraulic Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 510 Control by a Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 5101 Principle
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 5102 Principal Shapes of Elementary Signals
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 51021 Decaying Sinusoid
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 51022 ZERD Function
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 51023 WAVSIN Waveform
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 5103 Comparison of WAVSIN SHOC Waveforms and Decaying Sinusoid
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 5104 Criticism of Control by a Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 511 Pyrotechnic Shock Simulation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5111 Simulation Using Pyrotechnic Facilities
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5112 Simulation Using Metal-to-Metal Impact
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5113 Simulation Using Electrodynamic Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5114 Simulation Using Conventional Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53191ch6
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Chapter 6 Machine Condition Monitoring and Fault Diagnostics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 61 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 62 Machinery Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 621 Causes of Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 622 Types of Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 623 Frequency of Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 63 Basic Maintenance Strategies
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 631 Run-to-Failure (Breakdown) Maintenance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 632 Scheduled (Preventative) Maintenance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 633 Condition-Based (Predictive Proactive Reliability Centered On-Condition) Maintenance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 64 Factors Which Influence Maintenance Strategy
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 65 Machine Condition Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 651 Periodic Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 652 Continuous Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 66 Transducer Selection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 661 Noncontact Displacement Transducers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 662 Velocity Transducers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 663 Acceleration Transducers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 67 Transducer Location
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 68 Recording and Analysis Instrumentation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 681 Vibration Meters
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 682 Data Collectors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 683 Frequency-Domain Analyzers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 684 Time-Domain Instruments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 685 Tracking Analyzers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 69 Display Formats and Analysis Tools
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 691 Time Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6911 Time-Waveform Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6912 Time-Waveform Indices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6913 Time-Synchronous Averaging
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6914 Negative Averaging
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6915 Orbits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6916 Probability Density Functions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6917 Probability Density Moments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 692 Frequency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6921 Band-Pass Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6922 Shock Pulse (Spike Energy)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6923 Enveloped Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6924 Signature Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6925 Cascades (Waterfall Plots)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6926 Masks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6927 Frequency-Domain Indices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 693 Modal Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 694 Quefrency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 610 Fault Detection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 6101 Standards
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61011 Standards Based on Machinery Type
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61012 Standards Based on Vibration Severity
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 6102 Acceptance Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 61021 Statistical Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 6103 Frequency-Domain Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61031 Limited Band Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61032 Constant Bandwidth Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61033 Constant Percentage Bandwidth Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 611 Fault Diagnostics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 6111 Forcing Functions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61111 Unbalance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61112 Misalignment
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61113 Mechanical Looseness
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61114 Soft Foot
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61115 Rubs
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61116 Resonances
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61117 Oil Whirl
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61118 Oil Whip
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61119 Structural Vibrations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 611110 Foundation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 6112 Specific Machine Components
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 61121 Damaged or Worn Rolling-Element Bearings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 61122 Damaged or Worn Gears
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 6113 Specific Machine Types
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61131 Pumps
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61132 Fans
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61133 Electric Motors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61134 Steam and Gas Turbines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61135 Compressors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61136 Reciprocating Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 6114 Advanced Fault Diagnostic Techniques
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 53191ch7
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • Chapter 7 Vibration-Based Tool Condition Monitoring Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 71 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 72 Mechanics of Turning
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 721 General Terms
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 722 Chatter Vibrations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 723 Tool Wear
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7231 Tool Failure Mechanisms
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7232 Tool Failure Modes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7233 Tool Wear Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7234 Tool Wear Stages
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 73 Vibration Signal Recording
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 731 Direct and Indirect Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 732 Sensor Requirements for Tool Wear Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 733 Force Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7331 Direct Measurement Dynamometers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7332 Indirect Force Sensors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7333 Piezoelectric Strain Sensors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7334 Resistance Strain Gauges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7335 Customized Force Sensors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 734 Acceleration Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 735 Acoustic Emission Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 736 Sensor Comparisons
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 74 Signal Processing for Sensor-Based Tool Condition Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 741 Feature Extraction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7411 Time Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7412 Frequency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7413 Statistical Processing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7414 TimendashFrequency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 742 Feature Selection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 75 Wear ModelDecision-Making for Sensor-Based Tool Condition Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 751 Trending Threshold
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 752 Neural Networks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7521 Unsupervised Networks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7522 Supervised Networks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 753 Fuzzy Logic
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 754 Other Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 76 Conclusion
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53191ch8
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Chapter 8 Fault Diagnosis of Helicopter Gearboxes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 81 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 82 Abnormality Scaling
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 83 The Structure-Based Connectionist Network
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 84 Sensor Location Selection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 841 Coverage Index
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 842 Overlap Index
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 843 Monitoring Effectiveness
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 85 A Case Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 851 Structural and Featural Influences
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 852 Evaluation of Influences
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 853 Fault Detection Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 854 Fault Diagnostic Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 8541 Faulty Subsystem Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 8542 Faulty Component Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 855 Sensor Location Evaluation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 856 Sensor Location Validation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 86 Conclusion
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 53191ch9
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Chapter 9 Vibration Suppression and Monitoring in Precision Motion Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 91 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 92 Mechanical Design to Minimize Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 921 Stability and Static Determinacy of Machine Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 922 Two-Dimensional Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 923 Three-Dimensional Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 93 Adaptive Notch Filter
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 931 Fast Fourier Transform
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 932 Simulation and Experiments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 94 Real-Time Vibration Analyzer
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 941 Learning Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 942 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 943 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 944 Experiments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 9441 Input Variables mdash the Evaluation Criteria
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 94411 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 94412 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 9442 Evaluation Rules
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 94421 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 94422 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 9443 Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 94431 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 94432 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 95 Practical Insights and Case Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 96 Conclusions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 53191ch10
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Chapter 10 Vibration and Shock Problems of Civil Engineering Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 101 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 102 Earthquake-Induced Vibration of Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1021 Seismicity and Ground Motions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1022 Influence of Local Site Conditions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1023 Response of Structures to Ground Motions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1024 Dynamic Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10241 Equations of Motion for Linear Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10242 Equations of Motion for Linear Multiple-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1025 Earthquake Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10251 Elastic Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10252 Smoothed Design Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10253 Ductility-Modified Response Spectrum Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1026 Design Philosophy and the Code Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10261 Performance-Based Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1027 Analysis Options for Earthquake Effects
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10271 Dynamic Time History Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10272 Response Spectrum Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 102721 Response Spectrum Analysis of Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 102722 Response Spectrum Analysis of Multi-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10273 Equivalent Static Analysis (Force-Based Approach)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10274 Displacement-Based Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1028 SoilndashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1029 Active and Passive Control Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 10210 Worked Examples
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 103 Dynamic Effects of Wind Loading on Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1031 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1032 Wind Speed
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1033 Design Structures for Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10331 Types of Wind Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10332 Design Criteria
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10333 Static Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1034 Along and Across-Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10341 Along-Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10342 Across-Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1035 Wind Tunnel Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1036 Comfort Criteria Human Response to Building Motion
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1037 Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1038 Comparison with Earthquake Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 104 Vibrations Due to Fluid ndashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1041 Added Mass and Inertial Coupling
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1042 Wave-Induced Vibration of Structure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 105 Blast Loading and Blast Effects on Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1051 Explosions and Blast Phenomenon
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1052 Explosive Air-Blast Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10521 Blast Wave Scaling Laws
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10522 Prediction of Blast Pressure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1053 Gas Explosion Loading and Effect of Internal Explosions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1054 Structural Response to Blast Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10541 Elastic Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10542 Elasto-Plastic Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1055 Material Behaviors at High Strain Rate
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10551 Dynamic Properties of Concrete under High Strain Rates
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10552 Dynamic Properties of Reinforcing Steel under High Strain Rates
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1056 Failure Modes of Blast-Loaded Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10561 Global Structural Behavior
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10562 Localized Structural Behavior
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10563 PressurendashImpulse ( PndashI ) Diagrams
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1057 Blast WavendashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1058 Effect of Ground Shocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10581 Loads from Air-Induced Ground Shock
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10582 Loads from Direct Ground Shock
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1059 Technical Design Manuals for Blast-Resistant Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 10510 Computer Programs for Blast and Shock Effects
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 106 Impact Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1061 Structural Impact between Two Bodies mdash Hard Impact and Soft Impact
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1062 Example mdash Aircraft Impact
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 107 Floor Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1071 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1072 Types of Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10721 Walking
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10722 Rhythmic Activities
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10723 Mechanical Equipment
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10724 Analysis Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1073 Natural Frequency of Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10731 Computing the Natural Frequency
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10732 Computing Deflection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10733 Damping
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10734 Resonance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1074 Vibration Caused by Walking
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10741 Minimum Natural Frequency
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1075 Design for Rhythmic Excitation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10751 Harmonics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10752 Minimum Natural Frequency
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1076 Example mdash Vibration Analysis of a Reinforced Concrete Floor
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 53191ch11
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Chapter 11 Seismic Base Isolation and Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 111 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1111 From Ductility Design to Base Isolation and Control Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1112 The Importance of Reducing Seismic Input and Response
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 112 Seismic Base Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1121 Historical Development of Base Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1122 Basic Principle
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1123 Issues in Seismic Base Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11231 Performance Criteria
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11232 Type of Structure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11233 Site Characteristics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11234 Retrofit Issues
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11235 Design of Building Services
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11236 Expected Life of Isolator
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1124 Seismic Isolation Devices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11241 Laminated Rubber Bearings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11242 Lead Rubber Bearing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11243 Friction-Based Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11244 Other Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1125 Design of Isolation Devices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11251 High-Damping Rubber Bearing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112511 Stability against Buckling
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112512 Stability against Roll Out
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11252 Lead Rubber Bearings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112521 Design of Lead Plug
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112522 Design of Laminated Rubber Bearing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11253 Design of Friction Pendulum System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1126 Verification of Properties of Isolation Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11261 Tests for Isolation Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 112611 System Characterization Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 112612 Prototype Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 112613 Quality Control Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11262 Uniform Building Code Recommendations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112621 Units Dependent on Loading Rates
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112622 Units Dependent on Bilateral Load
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112623 System Adequacy
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1127 Analysis of Base-Isolated Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11271 Modeling of a Superstructure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11272 Modeling of Isolation System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11273 Static Analysis Procedure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11274 Dynamic Analysis Procedure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 112741 Response Spectrum Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 112742 Time-History Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11275 Software for Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1128 Experimental Methods for Isolated Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1129 Implementation of Seismic Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11291 New Construction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112911 Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112912 Bridges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11292 Seismic Retrofit
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112921 Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112922 Bridges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11293 Other Implementations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 11210 Performance during Past Earthquakes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 112101 Performance of Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 112102 Performance of Bridges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 113 Seismic Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1131 Historical Development of Seismic Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1132 Basic Principles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11321 Passive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11322 Active Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11323 Semiactive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11324 Hybrid Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11325 Categorization of Basic Principles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1133 Important Issues in Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11331 SoilndashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11332 DevicendashStructure Interaction and Time Delay
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11333 Design Guidelines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1134 Vibration-Control Devices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11341 Passive Control Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113411 Metallic Yielding Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113412 Friction Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113413 Viscoelastic Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113414 Viscous Fluid Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113415 Tuned Mass Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11342 Active Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113421 Electromagnetic Actuator
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113422 Hydraulic Actuators
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11343 Semiactive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113431 Variable-Orifice Hydraulic Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113432 Controllable Fluid Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113433 Controllable Friction Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11344 Hybrid Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1135 Control Algorithm
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11351 Active Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11352 Semiactive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113521 Common Control Schemes for Controllable Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113522 Special Control Schemes for Controllable Damper
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1136 Experimental Performance Verification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11361 Shaking Table Tests of a Flexible Structural Model with TMD AMD and ATMD
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11362 Substructure Hybrid Test
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113621 Hybrid Tests Using Hydraulic Actuator
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113622 Hybrid Tests Using Shaking Table
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113623 Hybrid Tests Using Inertia-Force-Driven Loading System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1137 Implementations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11371 Semiactive Control of Full-Scale Structures Using Variable Joint Damper System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113711 Background of Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113712 Test System Set Up
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113713 Control Algorithm
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113714 Test Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11372 Application of Structural Control Technologies to Seismic Retrofit of a Cable-Stayed Bridge
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113721 Background of Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113722 Basic Concept of Seismic Retrofit
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113723 Modal Shape Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113724 Time-History Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113725 Soil ndash Structure Interaction Effect
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113726 Semiactive Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53191ch12
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Chapter 12 Seismic Random Vibration of Long-Span Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 121 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1211 Basic Concepts of Random Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12111 Stationary Random Process
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12112 Nonstationary Random Process
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1212 Three Methods for Structural Seismic Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12121 Response Spectrum Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12122 Time-History Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12123 Random Vibration Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 121231 Davenport Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 121232 Vanmarcke Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 12124 Comparisons of the Three Seismic-Analysis Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 122 Seismic Random-Excitation Fields
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1221 Power Spectral Density of Spatially Varying Ground Acceleration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1222 Several Coherence Models
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12221 FengndashHu Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12222 Harichandran ndashVanmarcke Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12223 LohndashYeh Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12224 OliveirandashHaondashPenzien Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12225 LucondashWong Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12226 QundashWangndashWang Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1223 Generation of Ground Acceleration Power Spectral Density Curves from Acceleration Response Spectrum Curves
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12231 Kaul Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12232 Iteration Scheme
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1224 Seismic Equations of Motion of Long-Span Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1225 Seismic Waves and Their Geometrical Expressions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 123 Pseudoexcitation Method for Structural Random Vibration Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1231 Structures Subjected to Stationary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12311 Single Stationary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12312 Multiple Stationary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1232 Structures Subjected to Nonstationary Random Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12321 Structures Subjected to Uniformly Modulated Evolutionary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 123211 Single Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 123212 Multiple Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12322 Structures Subjected to Nonuniformly Modulated Evolutionary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 123221 Single Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 123222 Multiple Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1233 Precise Integration Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12331 Precise Integration of Exponential Matrices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12332 Particular Solutions and Precise Integration Formulas for Various Forms of Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 123321 Linear Loading Form (HPD-L Form)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 123322 Sinusoidal Loading Form (HPD-S Form)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 123323 Exponentially Decaying Sinusoidal Loading Form (HPD-E Form)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 124 Long-Span Structures Subjected to Stationary Random Ground Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1241 The Solution of Equations of Motion Using the Pseudoexcitation Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1242 Numerical Comparisons with Other Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12421 Song-Hua-Jiang Suspension Bridge
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 124211 All Supports Move Uniformly
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 124212 Wave Passage Effect Is Taken into Account
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 124213 Wave-Passage Effect and Incoherence Effect Are Jointly Taken into Account
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 12422 San Joaquin Concrete Bridge
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 125 Long-Span Structures Subjected to Nonstationary Random Ground Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1251 Modulation Functions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1252 The Formulas for Nonstationary Multiexcitation Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1253 Expected Extreme Values of Nonstationary Random Processes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1254 Numerical Comparisons with the Corresponding Stationary Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 126 Conclusions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 53191ch13
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Chapter 13 Seismic Qualification of Equipment
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 131 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 132 Distribution Qualification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1321 Drive-Signal Generation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1322 Distribution Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1323 Test Procedures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 133 Seismic Qualification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1331 Stages of Seismic Qualification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1332 Test Preliminaries
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1333 Single-Frequency Testing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1334 Multifrequency Testing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1335 Generation of RRS Specifications
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 53191ch14
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Chapter 14 Human Response to Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 141 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 142 Vibration Excitations on Humans
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1421 Excitation Characteristics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 143 Human Response to Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1431 Vibration Perception
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1432 Frequency Weighting Curve
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1433 Iso-Perception Curves
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1434 Detection Threshold Curve
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 144 Regulation of Human Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1441 Acceptable Vibration Levels in Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1442 Whole-Body Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1443 HandndashArm Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
Page 2: Vibration Monitoring, Testing, and Instrumentationpreview.kingborn.net › 646000 › d1a74678d91943e5ba1d5e... · The MEMS Handbook, Second Edition MEMS: Introduction and Fundamentals

Mechanical Engineering SeriesFrank Kreith and Roop Mahajan - Series Editors

Published Titles

Computer Techniques in VibrationClarence W de SilvaDistributed Generation The Power Paradigm forthe New MillenniumAnne-Marie Borbely ampJan F KreiderElastoplasticity TheoryVlado A LubardaEnergy Audit of Building SystemsAn Engineering ApproachMoncefKrartiEngineering ExperimentationEuan SomerscalesEntropy Generation MinimizationAdrian BejanFinite Element Method Using MATLABreg2 n d EditionYoung W Kwon amp Hyochoong BangFluid Power Circuits and Controls Fundamentalsand ApplicationsJohn S CundiffFundamentals of Environmental DischargeModelingLorin R DavisHeat Transfer in Single and Multiphase SystemsGregF NatererIntroductory Finite Element MethodChandrakant S Desai amp Tribikram KunduIntelligent Transportation Systems New Principlesand ArchitecturesSumit Ghosh amp Tony LeeMathematical amp Physical Modeling of MaterialsProcessing OperationsOlusegun Johnson Ilegbusi Manabu Iguchi ampWalter E WahnsiedlerMechanics of Composite MaterialsAutarK Kaw

Mechanics of FatigueVladimir V BolotinMechanics of Solids and Shells Theories andApproximationsGerald Wempner amp Demosthenes TalaslidisMechanism Design Enumeration of KinematicStructures According to FunctionLung-Wen Tsai

The MEMS Handbook Second EditionMEMS Introduction and FundamentalsMEMS Design and FabricationMEMS Applications

Mohamed Gad-el-HakNanotechnology Understanding Small SystemsBen Rogers Jesse Adams amp Sumita PennathurNonlinear Analysis of StructuresM SathyamoorthyPractical Inverse Analysis in EngineeringDavid M Trujillo amp Henry R BusbyPressure Vessels Design and PracticeSomnath ChattopadhyayPrinciples of Solid MechanicsRowland Richards JrThermodynamics for EngineersKau-Fui WongVibration Damping Control and DesignClarence W de SilvaVibration Monitoring Testing and InstrumentationClarence W de SilvaVibration and Shock HandbookClarence W de SilvaViscoelastic SolidsRoderic S Lakes

copy 2007 by Taylor amp Francis Group LLC

Vibration MonitoringTesting and

Instrumentation

Edited by

Clarence W de SilvaThe University of British Columbia

Vancouver Canada

Ltfi) CRC PressVV^ J Taylor amp Francis Group

Boca Raton London New York

CRC Press is an imprint of theTaylor amp Francis Croup an informa business

copy 2007 by Taylor amp Francis Group LLC

This material was previously published in Vibration and Shock Handbook copy 2005 by CRC Press LLC

CRC PressTaylor amp Francis Group6000 Broken Sound Parkway NW Suite 300Boca Raton FL 33487-2742

copy 2007 by Taylor amp Francis Group LLCCRC Press is an imprint of Taylor amp Francis Group an Informa business

No claim to original US Government worksPrinted in the United States of America on acid-free paper10987654321

International Standard Book Number-101-4200-5319-1 (Hardcover)International Standard Book Number-13978-1-4200-5319-7 (Hardcover)

This book contains information obtained from authentic and highly regarded sources Reprinted material is quotedwith permission and sources are indicated A wide variety of references are listed Reasonable efforts have been made topublish reliable data and information but the author and the publisher cannot assume responsibility for the validity ofall materials or for the consequences of their use

No part of this book may be reprinted reproduced transmitted or utilized in any form by any electronic mechanical orother means now known or hereafter invented including photocopying microfilming and recording or in any informa-tion storage or retrieval system without written permission from the publishers

For permission to photocopy or use material electronically from this work please access wwwcopyrightcom (httpwwwcopyrightcom) or contact the Copyright Clearance Center Inc (CCC) 222 Rosewood Drive Danvers MA 01923978-750-8400 CCC is a not-for-profit organization that provides licenses and registration for a variety of users For orga-nizations that have been granted a photocopy license by the CCC a separate system of payment has been arranged

Trademark Notice Product or corporate names may be trademarks or registered trademarks and are used only foridentification and explanation without intent to infringe

Library of Congress Cataloging-in-Publication Data

Vibration monitoring testing and instrumentation editor Clarence W de Silvap cm mdash (Mechanical engineering series)

Includes bibliographical references and indexISBN-13 978-1-4200-5319-7 (alk paper)ISBN-101-4200-5319-1 (alk paper)1 Vibration 2 Shock (Mechanics) I De Silva Clarence W II Title III Series

TA355V5228 200762030287-dc22 2006100139

Visit the Taylor amp Francis Web site athttpwwwtaylorandfranciscom

and the CRC Press Web site athttpwwwcrcpresscom

copy 2007 by Taylor amp Francis Group LLC

Preface

Individual chapters authored by distinguished leaders and experienced professionals in their

respective topics this book provides for engineers technicians designers researchers educators and

students a convenient thorough up-to-date and authoritative reference source on techniques tools

and data for monitoring testing and instrumentation of mechanical vibration and shock Included

are shock and vibration methodologies particularly for civil and mechanical engineering systems

instrumentation and testing methods including sensors exciters signal acquisition conditioning

and recording and LabVIEWw tools for virtual instrumentation testing and design for seismic

vibration and related regulatory issues and human response to vibration Important information

and results are summarized as windows tables graphs and lists throughout the chapters for easy

reference and information tracking References are given at the end of each chapter for further

information and study Cross-referencing is used throughout to indicate other places in the book

where further information on a particular topic is provided

In the book equal emphasis is given to theory and practical application Analytical

formulations design approaches monitoring and testing techniques and commercial software

tools are presented and illustrated Commercial equipment computer hardware and instrumenta-

tion are described analyzed and demonstrated for field application practical implementation and

experimentation Examples and case studies are given throughout the book to illustrate the use

and application of the included information The material is presented in a format that is

convenient for easy reference and recollection

Mechanical vibration is a manifestation of the oscillatory behavior in mechanical systems as a

result of either the repetitive interchange of kinetic and potential energies among components in

the system or a forcing excitation that is oscillatory Such oscillatory responses are not limited to

purely mechanical systems and are found in electrical and fluid systems as well In purely thermal

systems however free natural oscillations are not possible and an oscillatory excitation is needed

to obtain an oscillatory response Sock is vibration caused by brief abrupt and typically high-

intensity excitations Low levels of vibration mean reduced noise and improved work environment

Consequently a considerable effort is devoted today to monitoring studying and modifying the

vibration and shock generated by machinery components machine tools transit vehicles impact

processes civil engineering structures fluid flow systems and aircraft Before designing a system

for good vibratory or shock performance it is important to understand analyze and represent the

dynamic characteristics of the system This may be accomplished through monitoring testing and

analysis of test data which is the emphasis of this book

In recent years educators researchers and practitioners have devoted considerable effort towards

studying monitoring and testing vibration and shock in a range of applications in various branches

of engineering particularly civil mechanical aeronautical and aerospace and production and

v

53191mdash1432007mdash1850mdashVELUmdash246493mdash CRC ndash pp 1ndash15

copy 2007 by Taylor amp Francis Group LLC

manufacturing Specific applications are found in machine tools transit vehicles impact processes

civil engineering structures construction machinery industrial processes product qualification and

quality control fluid flow systems ships and aircraft This book is a contribution towards these

efforts

Clarence W de SilvaEditor-in-Chief

Vancouver Canada

Prefacevi

53191mdash1432007mdash1850mdashVELUmdash246493mdash CRC ndash pp 1ndash15

copy 2007 by Taylor amp Francis Group LLC

Acknowledgments

I wish to express my gratitude to the authors of the chapters for their valuable and highly professional

contributions I am very grateful to Michael Slaughter Acquisitions Editor-Engineering CRC Press for

his enthusiasm and support throughout the project Editorial and production staff at CRC Press have

done an excellent job in getting this volume out in print Finally I wish to lovingly acknowledge the

patience and understanding of my family

vii

53191mdash1432007mdash1850mdashVELUmdash246493mdash CRC ndash pp 1ndash15

copy 2007 by Taylor amp Francis Group LLC

Editor-in-Chief

Dr Clarence W de Silva PEng Fellow ASME Fellow IEEE Fellow Canadian Academy of

Engineering is Professor of Mechanical Engineering at the University of British Columbia Vancouver

Canada and has occupied the NSERC-BC Packers Research Chair in Industrial Automation since 1988

He has earned PhD degrees from the Massachusetts Institute of Technology and the University of

Cambridge England De Silva has also occupied the Mobil Endowed Chair Professorship in the

Department of Electrical and Computer Engineering at the National University of Singapore He has

served as a consultant to several companies including IBM and Westinghouse in US and has led the

development of eight industrial machines and devices He is recipient of the Henry M Paynter

Outstanding Investigator Award from the Dynamic Systems and Control Division of the American

Society of Mechanical Engineers (ASME) Killam Research Prize Lifetime Achievement Award from the

World Automation Congress Outstanding Engineering Educator Award of IEEE Canada Yasundo

Takahashi Education Award of the Dynamic Systems and Control Division of ASME IEEE Third

Millennium Medal Meritorious Achievement Award of the Association of Professional Engineers of BC

and the Outstanding Contribution Award of the Systems Man and Cybernetics Society of the Institute

of Electrical and Electronics Engineers (IEEE)

He has authored 16 technical books including Sensors and Actuators Control System Instrumentation

(Taylor amp Francis CRC Press 2007) MechatronicsmdashAn Integrated Approach (Taylor amp Francis CRC

Press Boca Raton FL 2005) Soft Computing and Intelligent Systems DesignmdashTheory Tools and

Applications (with F Karry Addison Wesley New York NY 2004) VIBRATION Fundamentals and

Practice (Taylor amp Francis CRC Press 2nd edition 2006) INTELLIGENT CONTROL Fuzzy Logic

Applications (Taylor amp Francis CRC Press 1995) Control Sensors and Actuators (Prentice Hall 1989) 14

edited volumes over 170 journal papers 200 conference papers and 12 book chapters He has served on

the editorial boards of 14 international journals in particular as the Editor-in-Chief of the International

Journal of Control and Intelligent Systems Editor-in-Chief of the International Journal of Knowledge-Based

Intelligent Engineering Systems Senior Technical Editor of Measurements and Control and Regional

Editor North America of Engineering Applications of Artificial Intelligence ndash the International Journal of

Intelligent Real-Time Automation He is a Lilly Fellow at Carnegie Mellon University NASA-ASEE Fellow

Senior Fulbright Fellow at Cambridge University ASI Fellow and a Killam Fellow Research and

development activities of Professor de Silva are primarily centered in the areas of process automation

robotics mechatronics intelligent control and sensors and actuators with cash funding of about $6

million as principal investigator

ix

53191mdash1432007mdash1850mdashVELUmdash246493mdash CRC ndash pp 1ndash15

copy 2007 by Taylor amp Francis Group LLC

Contributors

xi

Kourosh DanaiUniversity of Massachusetts

Amherst Massachusetts

Clarence W de SilvaThe University of British Columbia

Vancouver British Columbia Canada

P S HeynsUniversity of Pretoria

Pretoria South Africa

S HuangNational University of Singapore

Singapore

Hirokazu IemuraKyoto University

Kyoto Japan

Sarvesh Kumar JainMadhav Institute of Technology and

Science

Madhya Pradesh India

Christian LalanneEngineering Consultant

Jalles France

TH LeeNational University of Singapore

Singapore

YP LeowSingapore Institute of Manufacturing

Technology

Singapore

SY LimSingapore Institute of Manufacturing

Technology

Singapore

Jiaohao LinDalian University of Technology

Liaoning Peoplersquos Republic of China

W LinSingapore Institute of Manufacturing

Technology

Singapore

Chris K MechefskeQueenrsquos University

Kingston Ontario Canada

Priyan MendisUniversity of Melbourne

Melbourne Victoria Australia

Tuan NgoUniversity of Melbourne

Melbourne Victoria Australia

Mulyo Harris PradonoKyoto University

Kyoto Japan

C SchefferUniversity of Stellenbosch

Pretoria South Africa

KK TanNational University of Singapore

Singapore

KZ TangNational University of Singapore

Singapore

Yahui ZhangDalian University of Technology

Liaoning Peoplersquos Republic of China

53191mdash1432007mdash1850mdashVELUmdash246493mdash CRC ndash pp 1ndash15

copy 2007 by Taylor amp Francis Group LLC

Contents

1 Vibration Instrumentation Clarence W de Silva 1-1

11 Introduction 1-1

12 Vibration Exciters 1-3

13 Control System 1-15

14 Performance Specification 1-21

15 Motion Sensors and Transducers 1-27

16 Torque Force and Other Sensors 1-50

Appendix 1A Virtual Instrumentation for Data Acquisition Analysis

and Presentation 1-73

2 Signal Conditioning and Modification Clarence W de Silva 2-1

21 Introduction 2-2

22 Amplifiers 2-2

23 Analog Filters 2-15

24 Modulators and Demodulators 2-29

25 AnalogndashDigital Conversion 2-37

26 Bridge Circuits 2-43

27 Linearizing Devices 2-49

28 Miscellaneous Signal Modification Circuitry 2-56

29 Signal Analyzers and Display Devices 2-62

3 Vibration Testing Clarence W de Silva 3-1

31 Introduction 3-1

32 Representation of a Vibration Environment 3-3

33 Pretest Procedures 3-24

34 Testing Procedures 3-37

35 Some Practical Information 3-52

4 Experimental Modal Analysis Clarence W de Silva 4-1

41 Introduction 4-1

42 Frequency-Domain Formulation 4-2

43 Experimental Model Development 4-8

44 Curve Fitting of Transfer Functions 4-10

45 Laboratory Experiments 4-18

46 Commercial EMA Systems 4-24

xiii

53191mdash1432007mdash1850mdashVELUmdash246493mdash CRC ndash pp 1ndash15

copy 2007 by Taylor amp Francis Group LLC

5 Mechanical Shock Christian Lalanne 5-1

51 Definitions 5-2

52 Description in the Time Domain 5-3

53 Shock Response Spectrum 5-4

54 Pyroshocks 5-17

55 Use of Shock Response Spectra 5-18

56 Standards 5-24

57 Damage Boundary Curve 5-26

58 Shock Machines 5-28

59 Generation of Shock Using Shakers 5-44

510 Control by a Shock Response Spectrum 5-52

511 Pyrotechnic Shock Simulation 5-58

6 Machine Condition Monitoring and Fault Diagnostics Chris K Mechefske 6-1

61 Introduction 6-2

62 Machinery Failure 6-2

63 Basic Maintenance Strategies 6-4

64 Factors Which Influence Maintenance Strategy 6-7

65 Machine Condition Monitoring 6-8

66 Transducer Selection 6-10

67 Transducer Location 6-14

68 Recording and Analysis Instrumentation 6-14

69 Display Formats and Analysis Tools 6-16

610 Fault Detection 6-21

611 Fault Diagnostics 6-25

7 Vibration-Based Tool Condition Monitoring Systems C Scheffer and PS Heyns 7-1

71 Introduction 7-1

72 Mechanics of Turning 7-2

73 Vibration Signal Recording 7-7

74 Signal Processing for Sensor-Based Tool Condition Monitoring 7-11

75 Wear ModelDecision-Making for Sensor-Based Tool Condition Monitoring 7-15

76 Conclusion 7-20

8 Fault Diagnosis of Helicopter Gearboxes Kourosh Danai 8-1

81 Introduction 8-1

82 Abnormality Scaling 8-5

83 The Structure-Based Connectionist Network 8-8

84 Sensor Location Selection 8-11

85 A Case Study 8-14

86 Conclusion 8-23

9 Vibration Suppression and Monitoring in Precision Motion Systems KK Tan

TH Lee KZ Tang S Huang SY Lim W Lin and YP Leow 9-1

91 Introduction 9-1

92 Mechanical Design to Minimize Vibration 9-2

93 Adaptive Notch Filter 9-10

94 Real-Time Vibration Analyzer 9-17

Contentsxiv

53191mdash1432007mdash1850mdashVELUmdash246493mdash CRC ndash pp 1ndash15

copy 2007 by Taylor amp Francis Group LLC

95 Practical Insights and Case Study 9-29

96 Conclusions 9-35

10 Vibration and Shock Problems of Civil Engineering Structures Priyan Mendis

and Tuan Ngo 10-1

101 Introduction 10-2

102 Earthquake-Induced Vibration of Structures 10-3

103 Dynamic Effects of Wind Loading on Structures 10-22

104 Vibrations Due to FluidndashStructure Interaction 10-33

105 Blast Loading and Blast Effects on Structures 10-34

106 Impact Loading 10-47

107 Floor Vibration 10-51

11 Seismic Base Isolation and Vibration Control Hirokazu Iemura Sarvesh Kumar Jain

and Mulyo Harris Pradono 11-1

111 Introduction 11-1

112 Seismic Base Isolation 11-4

113 Seismic Vibration Control 11-33

12 Seismic Random Vibration of Long-Span Structures Jiahao Lin and Yahui Zhang 12-1

121 Introduction 12-2

122 Seismic Random-Excitation Fields 12-11

123 Pseudoexcitation Method for Structural Random Vibration Analysis 12-16

124 Long-Span Structures Subjected to Stationary Random Ground Excitations 12-27

125 Long-Span Structures Subjected to Nonstationary Random Ground Excitations 12-34

126 Conclusions 12-39

13 Seismic Qualification of Equipment Clarence W de Silva 13-1

131 Introduction 13-1

132 Distribution Qualification 13-1

133 Seismic Qualification 13-6

14 Human Response to Vibration Clarence W de Silva 14-1

141 Introduction 14-1

142 Vibration Excitations on Humans 14-2

143 Human Response to Vibration 14-3

144 Regulation of Human Vibration 14-6

Contents xv

53191mdash1432007mdash1850mdashVELUmdash246493mdash CRC ndash pp 1ndash15

copy 2007 by Taylor amp Francis Group LLC

1Vibration

Instrumentation

Clarence W de SilvaThe University of British Columbia

11 Introduction 1-1

12 Vibration Exciters 1-3Shaker Selection dagger Dynamics of Electromagnetic Shakers

13 Control System 1-15Components of a Shaker Controller dagger Signal-Generating

Equipment

14 Performance Specification 1-21Parameters for Performance Specification dagger Linearity dagger

Instrument Ratings dagger Accuracy and Precision

15 Motion Sensors and Transducers 1-27Potentiometer dagger Variable-Inductance Transducers dagger

Mutual-Induction Proximity Sensor dagger Selfinduction

Transducers dagger Permanent-Magnet Transducers dagger

Alternating Current Permanent-Magnet Tachometer dagger

Alternating Current Induction Tachometer dagger Eddy Current

Transducers dagger Variable-Capacitance Transducers dagger

Piezoelectric Transducers

16 Torque Force and Other Sensors 1-50Strain Gage Sensors dagger Miscellaneous Sensors

Appendix 1A Virtual Instrumentation for DataAcquisition Analysis and Presentation 1-73

Summary

Devices useful in instrumenting a mechanical vibrating system are presented in this chapter Shakers whichgenerate vibration excitations are discussed and compared A variety of sensors including motion sensorsproximity sensors forcetorque sensors and other miscellaneous sensors are considered Performance specificationin the time domain and the frequency domain is addressed Rating parameters of instruments are given

11 Introduction

Measurement and associated experimental techniques play a significant role in the practice of vibration

Academic exposure to vibration instrumentation usually arises in laboratories in the context of learning

training and research In vibration practice perhaps the most important task of instrumentation is the

measurement or sensing of vibration Vibration sensing is useful in the following applications

1 Design and development of a product

2 Testing (screening) of a finished product for quality assurance

3 Qualification of a good-quality product to determine its suitability for a specific application

1-1

53191mdash522007mdash1201mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

4 Mechanical aging of a product prior to carrying out a test program

5 Exploratory testing of a product to determine its dynamic characteristics such as resonances

mode shapes and even a complete dynamic model

6 Vibration monitoring for performance evaluation

7 Control and suppression of vibration

Figure 11 indicates a procedure typical of experimental vibration highlighting the essential

instrumentation Vibrations are generated in a device the test object in response to some excitation In

some experimental procedures primarily in vibration testing (see Figure 11) the excitation signal has

to be generated in a signal generator in accordance with some requirement (specification) and applied to

the object through an exciter after amplification and conditioning In some other situations primarily in

performance monitoring and vibration control the excitations are generated as an integral part of the

operating environment of the vibrating object and may originate either within the object (eg engine

excitations in an automobile) or in the environment with which the object interacts during operation

(eg road disturbances on an automobile) Sensors are needed to measure vibrations in the test object In

particular a control sensor is used to check whether the specified excitation is applied to the object

and one or more response sensors may be used to measure the resulting vibrations at key locations of

the object

The sensor signals have to be properly conditioned for example by filtering and amplification and

modified for example through modulation demodulation and analog-to-digital conversion prior to

recording analyzing and display The purpose of the controller is to guarantee that the excitation is

correctly applied to the test object If the signal from the control sensor deviates from the required

excitation the controller modifies the signal to the exciter so as to reduce this deviation Furthermore the

controller will stabilize or limit (compress) the vibrations in the object It follows that instruments in

experimental vibration may be generally classified into the following categories

1 Signal-generating devices

2 Vibration exciters

3 Sensors and transducers

4 Signal conditioningmodifying devices

5 Signal analysis devices

6 Control devices

7 Vibration recording and display devices

AnalogDigital

Interface

DigitalSignal

RecorderAnalyzerDisplay

FilterAmplifier

FilterAmplifier

SignalGenerator

and ExciterController

Reference (Required)Signal (Specification)

PowerAmplifier

MountingFixtures

TestObject

ResponseSensor

ControlSensor

Exciter

SwivelBase

FIGURE 11 Typical instrumentation in experimental vibration

Vibration Monitoring Testing and Instrumentation1-2

53191mdash522007mdash1201mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

Note that one instrument may perform the tasks

of more than one category listed here Also more

than one instrument may be needed to carry out

tasks in a single category In the following sections

we will provide some examples of the types of

vibration instrumentation giving characteristics

operating principles and important practical

considerations Also we will describe several

experiments which can be found in a typical

vibration laboratory

An experimental vibration system generally

consists of four main subsystems

1 Test object

2 Excitation system

3 Control system

4 Signal acquisition and modification system

These are schematically shown in Figure 12 Note that various components shown in Figure 11 may

be incorporated into one of these subsystems In particular component matching hardware and object

mounting fixtures may be considered interfacing devices that are introduced through the interaction

between the main subsystems as shown in Figure 12 Some important issues of vibration testing and

instrumentation are summarized in Box 11

12 Vibration Exciters

Vibration experimentation may require an external exciter to generate the necessary vibration This is the

case in controlled experiments such as product testing where a specified level of vibration is applied to the

test object and the resulting response is monitored A variety of vibration exciters are available with

different capabilities and principles of operation

Three basic types of vibration exciters (shakers) are widely used hydraulic shakers inertial shakers

and electromagnetic shakers The operation-capability ranges of typical exciters in these three categories

are summarized in Table 11 Stroke or maximum displacement is the largest displacement the exciter

is capable of imparting onto a test object whose weight is assumed to be within its design load limit

Maximum velocity and acceleration are similarly defined Maximum force is the largest force that could

be applied by the shaker to a test object of acceptable weight (one within the design load) The values

given in Table 11 should be interpreted with caution Maximum displacement is achieved only at very

low frequencies The achievement of maximum velocity corresponds to intermediate frequencies in the

operating frequency range of the shaker Maximum acceleration and force ratings are usually achieved at

high frequencies It is not feasible for example to operate a vibration exciter at its maximum

displacement and its maximum acceleration simultaneously

Consider a loaded exciter that is executing harmonic motion Its displacement is given by

x frac14 s sin vt eth11THORN

in which s is the displacement amplitude (or stroke) Corresponding velocity and acceleration are

_x frac14 sv cos vt eth12THORN

eurox frac14 2sv2sin vt eth13THORN

SignalModification

System

TestObject

ControlSystem

VibrationExciter (Shaker)

System

FIGURE 12 Interactions between major subsystems of

an experimental vibration system

Vibration Instrumentation 1-3

53191mdash522007mdash1201mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

If the velocity amplitude is denoted by v and the acceleration amplitude by a it follows from Equation

12 and Equation 13 thatv frac14 vs eth14THORN

and

a frac14 vv eth15THORN

Box 11

VIBRATION INSTRUMENTATION

Vibration Testing Applications for Products

Design and Development Production Screening and Quality Assessment Utilization and Qualification for Special Applications

Testing Instrumentation

Exciter (excites the test object) Controller (controls the exciter for accurate excitation) Sensors and Transducers (measure excitations and responses and provide excitation error

signals to controller) Signal Conditioning (converts signals to appropriate form) Recording and Display (perform processing storage and documentation)

Exciters

Shakers

1 Electrodynamic (high bandwidth moderate power complex and multifrequency

excitations)

2 Hydraulic (moderate to high bandwidth high power complex and multifrequency

excitations)

3 Inertial (low bandwidth low power single-frequency harmonic excitations)

TransientInitial Condition

1 Hammers (impulsive bump tests)

2 Cable Release (step excitations)

3 Drop (impulsive)

Signal Conditioning

Filters Amplifiers Amplifiers ModulatorsDemodulators ADCDAC

Sensors

Motion (displacement velocity acceleration) Force (strain torque)

Vibration Monitoring Testing and Instrumentation1-4

53191mdash522007mdash1201mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

TABLE 11 Typical Operation-Capability Ranges for Various Shaker Types

Shaker Type Typical Operational Capabilities

Frequency Maximum Displacement

(Stroke)

Maximum

Velocity

Maximum

Acceleration

Maximum

Force

Excitation

Waveform

Hydraulic

(electrohydraulic)

Low

(01ndash500 Hz)

High (20 in 50 cm) Intermediate

(50 insec

125 cmsec)

Intermediate

(20 g)

High (100000 lbf

450000 N)

Average flexibility (simple

to complex and random)

Inertial

(counter-rotating mass)

Intermediate

(2ndash50 Hz)

Low (1 in 25 cm) Intermediate

(50 insec

125 cmsec)

Intermediate

(20 g)

Intermediate

(1000 lbf 4500 N)

Sinusoidal only

Electromagnetic

(electrodynamic)

High

(2ndash10000 Hz)

Low (1 in 25 cm) Intermediate

(50 insec

125 cmsec)

High (100 g) Low to intermediate

(450 lbf 2000 N)

High flexibility and accuracy

(simple to complex and

random)

VibrationInstru

mentation

1-5

53191mdash522007mdash

1201mdashSENTHILKUMARmdash246494mdash

CRCndashpp1ndash112

copy 2007 by Taylor amp Francis Group LLC

An idealized performance curve of a shaker

has a constant displacementndashamplitude region a

constant velocityndashamplitude region and a con-

stant accelerationndashamplitude region for low

intermediate and high frequencies respectively

in the operating frequency range Such an ideal

performance curve is shown in Figure 13(a) on a

frequencyndashvelocity plane Logarithmic axes are

used In practice typical shaker performance

curves would be fairly smooth yet nonlinear

curves similar to those shown in Figure 13(b)

As the mass increases the performance curve

compresses Note that the acceleration limit of a

shaker depends on the mass of the test object

(load) Full load corresponds to the heaviest object

that could be tested The ldquono loadrdquo condition

corresponds to a shaker without a test object To

standardize the performance curves they are

usually defined at the rated load of the shaker A

performance curve in the frequencyndashvelocity

plane may be converted to a curve in the

frequencyndashacceleration plane simply by increasing

the slope of the curve by a unit magnitude (ie

20 dbdecade)

Several general observations can be made from

Equation 14 and Equation 15 In the constant-

peak displacement region of the performance

curve the peak velocity increases proportionally

with the excitation frequency and the peak

acceleration increases with the square of the excitation frequency In the constant-peak velocity region

the peak displacement varies inversely with the excitation frequency and the peak acceleration increases

proportionately In the constant-peak acceleration region the peak displacement varies inversely with the

square of the excitation frequency and the peak velocity varies inversely with the excitation frequency

This further explains why rated stroke maximum velocity and maximum acceleration values are not

simultaneously realized

121 Shaker Selection

Vibration testing is accomplished by applying a specified excitation to the test package using a shaker

apparatus and monitoring the response of the test object Test excitation may be represented by its

response spectrum The test requires that the response spectrum of the actual excitation known as the

test response spectrum (TRS) envelops the response spectrum specified for the particular test known as

the required response spectrum (RRS)

A major step in the planning of any vibration testing program is the selection of a proper shaker

(exciter) system for a given test package The three specifications that are of primary importance in

selecting a shaker are the force rating the power rating and the stroke (maximum displacement) rating

Force and power ratings are particularly useful in moderate to high frequency excitations and the stroke

rating is the determining factor for low frequency excitations In this section a procedure is given to

determine conservative estimates for these parameters in a specified test for a given test package

Frequency domain considerations are used here

Stroke

Limit M

ax

Acceleration

MaxVelocity

Peak

Vel

ocity

(cm

s)

01 1 10 100

FullLoad

NoLoad

Frequency (Hz)(a)

Peak

Vel

ocity

(cm

s)

100

10

1

100

10

1

01 1 10 100

FullLoad

NoLoad

Frequency (Hz)(b)

FIGURE 13 Performance curve of a vibration exciter

in the frequencyndashvelocity plane (log) (a) ideal (b)

typical

Vibration Monitoring Testing and Instrumentation1-6

53191mdash522007mdash1201mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

1211 Force Rating

In the frequency domain the (complex) force at the exciter (shaker) head is given by

F frac14 mHethvTHORNasethvTHORN eth16THORNin which v is the excitation frequency variable m is the total mass of the test package including

mounting fixture and attachments asethvTHORN is the Fourier spectrum of the support-location (exciter head)

acceleration and H(v) is frequency response function that takes into account the flexibility and

damping effects (dynamics) of the test package apart from its inertia In the simplified case where the

test package can be represented by a simple oscillator of natural frequency vn and damping ratio by zt

this function becomes

HethvTHORN frac14 1thorn 2jztv=vn=12 ethv=vnTHORN2 thorn 2jztv=vn eth17THORNin which j frac14 ffiffiffiffi

21p

This approximation is adequate for most practical purposes The static weight of the

test object is not included in Equation 16 Most heavy-duty shakers which are typically hydraulic

have static load support systems such as pneumatic cushion arrangements that can exactly balance the

dead load The exciter provides only the dynamic force In cases where shaker directly supports the

gravity load in the vertical test configuration Equation 16 should be modified by adding a term to

represent this weight

A common practice in vibration test applications is to specify the excitation signal by its response

spectrum This is simply the peak response of a simple oscillator expressed as a function of its natural

frequency when its support location is excited by the specified signal Clearly the damping of the simple

oscillator is an added parameter in a response spectrum specification Typical damping ratios ethzrTHORN used inresponse spectra specifications are less than 01 (or 10) It follows that an approximate relationship

between the Fourier spectrum of the support acceleration and its response spectrum is

as frac14 2jzrarethvTHORN eth18THORNThe magnitude larethvTHORNl is the response spectrumEquation 18 substituted into Equation 16 gives

F frac14 mHethvTHORN2jzrarethvTHORN eth19THORNIn view of Equation 17 for test packages having low damping the peak value of H(v) is

approximately 1=eth2jztTHORN this should be used in computing the force rating if the test package has a

resonance within the frequency range of testing On the other hand if the test package is assumed to be

rigid then HethvTHORN oslash 1 A conservative estimate for the force rating is

Fmax frac14 methzr=ztTHORNlarethvTHORNlmax eth110THORNIt should be noted that larethvTHORNlmax is the peak value of the specified (required) response spectrum (RRS)

for acceleration

1212 Power Rating

The exciter head does not develop its maximum force when driven at maximum velocity Output power

is determined by using

p frac14 Refrac12FvsethvTHORN eth111THORNin which vsethvTHORN is the Fourier spectrum of the exciter velocity and Re [ ] denotes the real part of a complex

function Note that as frac14 jvvs Substituting Equation 16 and Equation 18 into Equation 111 gives

p frac14 eth4mz2r =vTHORNRefrac12jHethvTHORNa2r ethvTHORN eth112THORNIt follows that a conservative estimate for the power rating is

pmax frac14 2methz2r =ztTHORNfrac12larethvTHORNl2=v max eth113THORN

Vibration Instrumentation 1-7

53191mdash522007mdash1201mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

Representative segments of typical acceleration RRS curves have slope n as given by

a frac14 k1vn eth114THORN

It should be clear from Equation 113 that the maximum output power is given by

pmax frac14 k2v2n21 eth115THORN

This is an increasing function for n 1=2 and a decreasing function for n 1=2 It follows that the power

rating corresponds to the highest point of contact between the acceleration RRS curve and a line of slope

equal to 12 A similar relationship may be derived if velocity RRS curves (having slopes n2 1) are used

1213 Stroke Rating

From Equation 18 it should be clear that the Fourier spectrum xs of the exciter displacement time

history can be expressed as

xs frac14 2zrarethvTHORN=jv2 eth116THORNAn estimate for stroke rating is

xmax frac14 2zrfrac12larethvTHORNl=v2 max eth117THORNThis is of the form

xmax frac14 kvn22 eth118THORNIt follows that the stroke rating corresponds to the highest point of contact between the acceleration

RRS curve and a line of slope equal to two

Example 11

A test package of overall mass 100 kg is to be

subjected to dynamic excitation represented by the

acceleration RRS (at 5 damping) as shown in

Figure 14 The estimated damping of the test

package is 7 The test package is known to have a

resonance within the frequency range of the

specified test Determine the exciter specifications

for the test

Solution

From the development presented in the previous

section it is clear that the point F (or P) in

Figure 14 corresponds to the force and output

power ratings and the point S corresponds to

the stroke rating The co-ordinates of these

critical points are F P frac14 eth42 Hz 40 gTHORN and S frac14 eth08 Hz 075 gTHORN Equation 110 gives the force

rating as

Fmax frac14 100 pound eth005=007THORN pound 40 pound 981 N frac14 2803 N

Equation 113 gives the power rating as

pmax frac14 2 pound 100 pound eth0052=007THORN pound frac12eth40 pound 981THORN2=42 pound 2p watts frac14 417 W

Equation 117 gives the stroke rating as

xmax frac14 2 pound 005 pound frac12eth075 pound 98THORN=eth08 pound 2pTHORN2 m frac14 3 cm

Acc

eler

atio

n(g

)

Con

stan

t Dis

plac

emen

t

Constant Velo

city

Frequency (Hz)

S

FP

0101

10 10 100

10

10

FIGURE 14 Test excitation specified by an accelera-

tion RRS (5 damping)

Vibration Monitoring Testing and Instrumentation1-8

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copy 2007 by Taylor amp Francis Group LLC

1214 Hydraulic Shakers

A typical hydraulic shaker consists of a piston-cylinder arrangement (also called a ram) a servo-valve a

fluid pump and a driving electric motor Hydraulic fluid (oil) is pressurized (typical operating pressure

4000 psi) and pumped into the cylinder through a servo-valve by means of a pump that is driven by an

electric motor (typical power 150 hp) The flow (typical rate 100 galmin) that enters the cylinder is

controlled (modulated) by the servo-valve which in effect controls the resulting piston (ram) motion

A typical servo-valve consists of a two-stage spool valve which provides a pressure difference and a

controlled (modulated) flow to the piston which sets it in motion

The servo-valve itself is moved by means of a linear torque motor which is driven by the excitation-

input signal (electrical) A primary function of the servo-valve is to provide a stabilizing feedback to the

ram In this respect the servo-valve complements the main control system of the test setup The ram is

coupled to the shaker table by means of a link with some flexibility The cylinder frame is mounted on the

support foundation with swivel joints This allows for some angular and lateral misalignment which

might be caused primarily by test-object dynamics as the table moves

Two-degree-of-freedom (Two-DoF) testing requires two independent sets of actuators and three-DoF

testing requires three independent actuator sets Each independent actuator set can consist of several

actuators operated in parallel using the same pump and the same excitation-input signal to the torque

motors

If the test table is directly supported on the vertical actuators they must withstand the total dead

weight (ie the weight of the test table the test object the mounting fixtures and the instrumentation)

This is requirement is usually prevented by providing a pressurized air cushion in the gap between the

test table and the foundation walls Air should be pressurized so as to balance the total dead weight

exactly (typical required gage pressure 3 psi)

Figure 15(a) shows the basic components of a typical hydraulic shaker The corresponding

operational block diagram is shown in Figure 15(b) It is desirable to locate the actuators in a pit in the

test laboratory so that the test tabletop is flushed with the test laboratory floor under no-load conditions

This minimizes the effort required to place the test object on the test table Otherwise the test object has

to be lifted onto the test table with a forklift Also installation of an aircushion to support the system

dead weight is difficult under these circumstances of elevated mounting

Hydraulic actuators are most suitable for heavy load testing and are widely used in industrial and civil

engineering applications They canbeoperated at very low frequencies (almost direct current [DC]) aswell

as at intermediate frequencies (see Table 11) Large displacements (stroke) are possible at low frequencies

Hydraulic shakers have the advantage of providing high flexibility of operation during the test their

capabilities include variable-force and constant-force testing and wide-band random-input testing The

velocity and acceleration capabilities of hydraulic shakers are moderate Although any general excitation-

input motion (for example sine wave sine beat wide-band random) can be used in hydraulic shakers

faithful reproduction of these signals is virtually impossible at high frequencies because of distortion and

higher-order harmonics introduced by the high noise levels that are common in hydraulic systems This

is only a minor drawback in heavy-duty intermediate-frequency applications Dynamic interactions are

reduced through feedback control

1215 Inertial Shakers

In inertial shakers or ldquomechanical excitersrdquo the force that causes the shaker-table motion is generated by

inertia forces (accelerating masses) Counter-rotating-mass inertial shakers are typical in this category

To understand their principle of operation consider two equal masses rotating in opposite directions at

the same angular speed v and in the same circle of radius r (see Figure 16) This produces a resultant

force equal to 2mv2r cos vt in a fixed direction (the direction of symmetry of the two rotating arms)

Consequently a sinusoidal force with a frequency of v and an amplitude proportional to v2 is generated

This reaction force is applied to the shaker table

Figure 17 shows a sketch of a typical counter-rotating-mass inertial shaker It consists of two identical

rods rotating at the same speed in opposite directions Each rod has a series of slots in which to

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place weights In this manner the magnitude of

the eccentric mass can be varied to achieve various

force capabilities The rods are driven by a

variable-speed electric motor through a gear

mechanism that usually provides several speed

ratios A speed ratio is selected depending on the

required test-frequency range The whole system is

symmetrically supported on a carriage that is

directly connected to the test table The test object

is mounted on the test table The preferred

mounting configuration is horizontal so that the

excitation force is applied to the test object in a

horizontal direction In this configuration there

are no variable gravity moments (weight pounddistance to center of gravity) acting on the drive

mechanism Figure 17 shows the vertical con-

figuration In dynamic testing of large structures

the carriage can be mounted directly on the

structure at a location where the excitation force

should be applied By incorporating two pairs of

counter-rotating masses it is possible to generate

test moments as well as test forces

FIGURE 15 A typical hydraulic shaker arrangement (a) schematic diagram (b) operational block diagram

m m

2mw2r cos wt

wtw w

wt

FIGURE 16 Principle of operation of a counter-

rotating-mass inertial shaker

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Reaction-type shakers driven by inertia are widely used for the prototype testing of civil engineering

structures Their first application dates back to 1935 Inertial shakers are capable of producing

intermediate excitation forces The force generated is limited by the strength of the carriage frame The

frequency range of operation and the maximum velocity and acceleration capabilities are also

intermediate for inertial shakers whereas the maximum displacement capability is typically low A major

limitation of inertial shakers is that their excitation force is exclusively sinusoidal and that the force

amplitude is directly proportional to the square of the excitation frequency As a result complex and

random excitation testing constant-force testing (for example transmissibility tests and constant-force

sine-sweep tests) and flexibility to vary the force amplitude or the displacement amplitude during a test

are not generally feasible with this type of shakers Excitation frequency and amplitude can be varied

during testing however by incorporating a variable-speed drive for the motor The sinusoidal excitation

generated by inertial shakers is virtually undistorted which gives them an advantage over the other types

of shakers when used in sine-dwell and sine-sweep tests Small portable shakers with low-force capability

are available for use in on-site testing

1216 Electromagnetic Shakers

In electromagnetic shakers or ldquoelectrodynamic excitersrdquo the motion is generated using the principle of

operation of an electric motor Specifically the excitation force is produced when a variable excitation

signal (electrical) is passed through a moving coil placed in a magnetic field

The components of a commercial electromagnetic shaker are shown in Figure 18 A steady magnetic

field is generated by a stationary electromagnet that consists of field coils wound on a ferromagnetic base

that is rigidly attached to a protective shell structure The shaker head has a coil wound around it When

the excitation electrical signal is passed through this drive coil the shaker head which is supported on

flexure mounts will be set in motion The shaker head consists of the test table on which the test object

is mounted Shakers with interchangeable heads are available The choice of appropriate shaker head is

based on the geometry and mounting features of the test object The shaker head can be turned to

different angles by means of a swivel joint In this manner different directions of excitation (in biaxial

and triaxial testing) can be obtained

FIGURE 17 Sketch of a counter-rotating-mass inertial shaker

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122 Dynamics of Electromagnetic Shakers

Consider a single axis electromagnetic shaker (Figure 18) with a test object having a single natural

frequency of importance within the test frequency range The dynamic interactions between the shaker

and the test object give rise to two significant natural frequencies (and correspondingly two significant

resonances) These appear as peaks in the frequency response curve of the test setup Furthermore the

natural frequency (resonance) of the test package alone causes a ldquotroughrdquo or depression (antiresonance)

in the frequency response curve of the overall test setup To explain this characteristic consider the

dynamic model shown in Figure 19 The following mechanical parameters are defined for

Figure 19(a) m k and b are the mass stiffness and equivalent viscous damping constant respectively

of the test package and me ke and be are the corresponding parameters of the exciter (shaker) Also in

the equivalent electrical circuit of the shaker head as shown in Figure 19(b) the following electrical

parameters are defined Re and Le are the resistance and (leakage) inductance and kb is the back

electromotive force (back emf) of the linear motor Assuming that the gravitational forces are supported

FIGURE 18 Schematic sectional view of a typical electromagnetic shaker manufactured by Bruel and Kjaer

Denmark

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by the static deflections of the flexible elements and that the displacements are measured from the static

equilibrium position we have the following system equations

Test object meuroy frac14 2kethy2 yeTHORN2 beth_y2 _yeTHORN eth119THORNShaker head me euroye frac14 fe thorn kethy2 yeTHORN thorn beth_y2 _yeTHORN2 key 2 be _ye eth120THORN

Electrical Lediedt

thorn Reie thorn kb _ye frac14 vethtTHORN eth121THORN

The electromagnetic force fe generated in the shaker head is a result of the interaction of the magnetic

field generated by the current ie with coil of the moving shaker head and the constant magnetic field

(stator) in which the head coil is located Here we have

fe frac14 kbie eth122THORNNote that v(t) is the voltage signal that is applied by the amplifier to the shaker coil ye is the displacement

of the shaker head and y is the displacement response of the test package

It is assumed that kb has consistent electrical and mechanical units (Vmsec and NA) Usually

the electrical time constant of the shaker is quite small compared with the primarily mechanical

time constants of the shaker and the test package In such cases the Ledie=dt term in Equation 121 may

be neglected Consequently the equations from Equation 119 through Equation 122 may be

expressed in the Laplace (frequency) domain with the Laplace variable s taking the place of the derivative

d=dt as

ethms2 thorn bsthorn kTHORNy frac14 ethbsthorn kTHORNye eth123THORN

FIGURE 19 Dynamic models of an electromagnetic shaker and a flexible test package (a) mechanical model

(b) electrical model

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frac12mes2 thorn ethbthorn beTHORNsthorn ethkthorn keTHORN ye frac14 ethbsthorn kTHORNy thorn kb

Rev2

k2bs

Reye eth124THORN

It follows that the transfer function of the shaker head motion with respect to the excitation voltage is

given by

yevfrac14 kb

Re

DethsTHORNDdethsTHORN eth125THORN

where DethsTHORN is the characteristic function of the primary dynamics of the test object

DethsTHORN frac14 ms2 thorn bsthorn k eth126THORN

and DdethsTHORN is the characteristic function of the primary dynamic interactions between the shaker and thetest object

DcethsTHORN frac14 mmes4 thorn frac12methbe thorn bthorn boTHORN thornmeb s

3 thorn frac12methke thorn kTHORN thornmekthorn bethbe thorn boTHORN s2thorn frac12bke thorn ethbe thorn boTHORNk sthorn kke

eth127THORN

where

bo frac14 k2bRe

eth128THORN

It is clear that under low damping conditions DdethsTHORN will produce two resonances as it is fourth order in sand similarly DethsTHORN will produce one antiresonance (trough) corresponding to the resonance of the testobject Note that in the frequency domain s frac14 jv and hence the frequency response function given by

Equation 125 is in fact

yevfrac14 kb

Rb

DethjvTHORNDdethjvTHORN eth129THORN

The magnitude of this frequency response function for a typical test system is sketched in Figure 110

Note that this curve is for the ldquoopen-looprdquo case where there is no feedback from the shaker controller

In practice the shaker controller will be able

to compensate for the resonances and anti-

resonances to some degree depending on its

effectiveness

The main advantages of electromagnetic

shakers are their high frequency range of

operation their high degree of operating flexi-

bility and the high level of accuracy of the

generated shaker motion Faithful reproduction

of complex excitations is possible because of the

advanced electronics and control systems used in

this type of shakers Electromagnetic shakers are

not suitable for heavy-duty applications (large test

objects) however High test-input accelerations

are possible at high frequencies when electromag-

netic shakers are used but their displacement and

velocity capabilities are limited to low or

intermediate values (see Table 11)

100

10

1 10 100Excitation Frequency (Hz)

Antiresonance

Resonance

Shak

erD

ispl

acem

entM

agni

tude

Resonance

1000

FIGURE 110 Frequency response curve of a typical

electromagnetic shaker with a test object

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1221 Transient Exciters

Other varieties of exciters are commonly used in

transient-type vibration testing In these tests

either an impulsive force or an initial excitation is

applied to the test object and the resulting

response is monitored The excitations and the

responses are ldquotransientrdquo in this case Hammer

test drop tests and pluck tests fall into this

category For example a hammer test may be

conducted by hitting the object with an instru-

mented hammer and then measuring the response

of the object The hammer has a force sensor at its

tip as sketched in Figure 111 A piezoelectric or

strain-gage type force sensor may be used More

sophisticated hammers have impedance heads in

place of force sensors An impedance head

measures force and acceleration simultaneously

The results of a hammer test will depend on many

factors for example the dynamics of the hammer

body how firmly the hammer is held during the

impact how quickly the impact is applied and

whether there are multiple impacts

13 Control System

The two primary functions of the shaker control system in vibration testing are (1) to guarantee that the

specified excitation is applied to the test object and (2) to ensure that the dynamic stability (motion

constraints) of the test setup is preserved An operational block diagram illustrating these control

functions is given in Figure 112 The reference input to the control system represents the desired

excitation force that should be applied to the test object In the absence of any control however the force

reaching the test object will be distorted primarily because of (1) dynamic interactions and

nonlinearities of the shaker the test table the mounting fixtures the auxiliary instruments and the test

object itself (2) noise and errors in the signal generator amplifiers filters and other equipment and (3)

external loads and disturbances acting on the test object and other components (for example external

restraints aerodynamic forces friction) To compensate for these distorting factors response

measurements (displacements velocities acceleration and so on) are made at various locations in the

test setup and are used to control the system dynamics In particular the responses of the shaker the test

table and the test object are measured These responses are used to compare the actual excitation felt by

FIGURE 111 An instrumented hammer used in bump

tests or hammer tests

ExcitationInput

(Reference)

Feedback Paths

DriveSignal

ShakerResponse

TestTable

TestObject

Test ObjectResponse

Test TableResponseExciter

(Shaker)(Ram)

Controllerand

Amplifier

FIGURE 112 Operational block diagram illustrating a general shaker control system

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the test object at the shaker interface with the desired (specified) input The drive signal to the shaker is

modified depending on the error that is present

Two types of control are commonly employed in shaker apparatus simple manual control and

complex automatic control Manual control normally consists of simple open-loop trial-and-error

methods of manual adjustments (or calibration) of the control equipment to obtain a desired dynamic

response The actual response is usually monitored (on an oscilloscope or frequency analyzer screen for

example) during manual-control operations The pretest adjustments in manual control can be very

time-consuming as a result the test object might be subjected to overtesting which could produce

cumulative damage is undesirable and could defeat the test purpose Furthermore the calibration

procedure for the experimental setup must be repeated for each new test object

The disadvantages ofmanual control suggest that automatic control is desirable in complex test schemes

in which high accuracy of testing is desired The first step of automatic control involves automatic

measurement of the system response using control sensors and transducers The measurement is then fed

back into the control system which instantaneously determines the best drive signal to actuate the shaker

in order to get the desired excitation This may be done by either analog or digital methods

Primitive control systems require an accurate mathematical description of the test object This

dependency of the control system on the knowledge of test-object dynamics is clearly undesirable

Performance of a good control system should not be considerably affected by the dynamic interactions

and nonlinearities of the test object or by the nature of the excitation Proper selection of feedback signals

and control-system components can reduce such effects and will make the system robust

In the response-spectrum method of vibration testing it is customary to use displacement control at

low frequencies velocity control at intermediate frequency and acceleration control at high frequencies

This necessitates feedback of displacement velocity and acceleration responses Generally however the

most important feedback is the velocity feedback In sine-sweep tests the shaker velocity must change

steadily over the frequency band of interest In particular the velocity control must be precise near the

resonances of the test object Velocity (speed) feedback has a stabilizing effect on the dynamics which is

desirable This effect is particularly useful in ensuring stability in motion when testing is done near

resonances of lightly damped test objects On the contrary displacement (position) feedback can have a

destabilizing effect on some systems particularly when high feedback gains are used

The controller usually consists of various instruments equipment and computation hardware and

software Often the functions of the data-acquisition and processing system overlap with those of the

controller to some extent As an example consider the digital-controller of vibration testing apparatus

First the responses are measured through sensors (and transducers) filtered and amplified

(conditioned) These data channels may be passed through a multiplexer whose purpose is to select

one data channel at a time for processing Most modern data acquisition hardware does not need a

separate multiplexer to handle multiple signals The analog data are converted into digital data using

analog-to-digital converters (ADCs) The resulting sampled data are stored on a disk or as a block data in

the computer memory The reference input signal (typically a signal recorded on an FM tape) is also

sampled (if it is not already in the digital form) using an ADC and fed into the computer Digital

processing is done on the reference signal and the response data with the objective of computing the

command signal to drive the shaker The digital command signal is converted into an analog signal using

a digital-to-analog converter (DAC) and amplified (conditioned) before it is used to drive the exciter

The nature of the control components depends to a large extent on the nature and objectives of the

particular test to be conducted Some of the basic components in a shaker controller are described in

the following subsections

131 Components of a Shaker Controller

1311 Compressor

A compressor circuit is incorporated in automatic excitation control devices to control the excitation-

input level automatically The level of control depends on the feedback signal from a control sensor and

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the specified (reference) excitation signal Usually the compressor circuit is included in the excitation-

signal generator (for example in a sine generator) The control by this means may be done on the basis of

a single-frequency component (eg the fundamental frequency)

1312 Equalizer (Spectrum Shaper)

Random-signal equalizers are used to shape the spectrum of a random signal in a desired manner In

essence and equalizer consists of a bank of narrow-band filters (for example 80 filters) in parallel over

the operating frequency range By passing the signal through each filter the spectral density (or the mean

square value) of the signal in that narrow frequency band (for example each one-third-octave band) is

determined This is compared with the desired spectral level and automatic adjustment is made in that

filter in case there is an error In some systems response-spectrum analysis is made in place of power

spectral density analysis In that case the equalizer consists of a bank of simple oscillators whose

resonant frequencies are distributed over the operating frequency range of the equalizer The feedback

signal is passed through each oscillator and the peak value of its output is determined This value is

compared with the desired response spectrum value at that frequency If there is an error automatic gain

adjustment is made in the appropriate excitation signal components

Random-noise equalizers are used in conjunction with random signal generators They receive

feedback signals from the control sensors In some digital control systems there are algorithms (software)

that are used to iteratively converge the spectrum of the excitation signal felt by the test object into the

desired spectrum

1313 Tracking Filter

Many vibration tests are based on single-frequency excitations In such cases the control functions

should be performed on the basis of the amplitudes of the fundamental-frequency component of the

signal A tracking filter is simply a frequency-tuned band-pass filter It automatically tunes the center

frequency of its very narrow-band-pass filter to the frequency of a carrier signal Then when a noisy

signal is passed through the tuned filter the output of the filter will be the required fundamental

frequency component in the signal Tracking filters also are useful in obtaining amplitudendashfrequency

plots using an XndashY plotter In such cases the frequency value comes from the signal generator (sweep

oscillator) which produces the carrier signal to the tracking filter The tracking filter then determines the

corresponding amplitude of a signal that is fed into it Most tracking filters have dual channels so that two

signals can be handled (tracked) simultaneously

1314 Excitation Controller (Amplitude Servo-Monitor)

An excitation controller is typically an integral part of the signal generator It can be set so that automatic

sweep between two frequency limits can be performed at a selected sweep rate (linear or logarithmic)

More advanced excitation controllers have the capability of an automatic switch-over between constant-

displacement constant-velocity and constant-acceleration excitation-input control at specified

frequencies over the sweep frequency interval Consequently integrator circuits should be present

within the excitation controller unit to determine velocities and displacements from acceleration signals

Sometimes integration is performed by a separate unit called a vibration meter This unit also offers

the operator the capability of selecting the desired level of each signal (acceleration velocity or

displacement) There is an automatic cut-off level for large displacement values that could result from

noise in acceleration signals A compressor is also a subcomponent of the excitation controller The

complete unit is sometimes known as an amplitude servo-monitor

132 Signal-Generating Equipment

Shakers are force-generating devices that are operated using drive (excitation) signals generated from a

source The excitation-signal source is known as the signal generator Three major types of signal

generators are used in vibration testing applications (1) oscillators (2) random-signal generators and

(3) storage devices In some units oscillators and random-signal generators are combined We shall

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copy 2007 by Taylor amp Francis Group LLC

discuss these two generators separately however because of their difference in function It also should be

noted that almost any digital signal (deterministic or random) can be generated by a digital computer

using a suitable computer program the signal eventually can be passed through a DAC to obtain

the corresponding analog signal These lsquodigitalrsquo signal generators along with analog sources such as

magnetic tape players (FM) are classified into the category of storage devices

The dynamic range of equipment is the ratio of the maximum and minimum output levels (expressed

in decibels) at which it is capable of operating without significant error This is an important specification

for many types of equipment particularly for signal-generating devices The output level of the signal

generator should be set to a value within its dynamic range

1321 Oscillators

Oscillators are essentially single-frequency generators Typically sine signals are generated but other

waveforms (such as rectangular and triangular pulses) are also available in most oscillators Normally

an oscillator has two modes of operation (1) sweeping up and down between two frequency limits and

(2) dwelling at a specified frequency In the sweep operation the sweep rate should be specified This can

be done either on a linear scale (Hzmin) or on a logarithmic scale (octavesmin) In the dwell operation

the frequency points (or intervals) should be specified In either case a desired signal level can be chosen

using the gain-control knob An oscillator that is operated exclusively in the sweep mode is called a sweep

oscillator

The early generation of oscillators employed variable inductor-capacitor types of electronic circuits to

generate signals oscillating at a desired frequency The oscillator is tuned to the required frequency by

varying the capacitance or inductance parameters A DC voltage is applied to energize the capacitor

and to obtain the desired oscillating voltage signal which subsequently is amplified and conditioned

Modern oscillators use operational amplifier circuits along with resistor capacitor and semiconductor

(SC) elements Also common are crystal (quartz) parallel-resonance oscillators used to generate voltage

signals accurately at a fixed frequency The circuit is activated using a DC-voltage source Other

frequencies of interest are obtained by passing this high-frequency signal through a frequency converter

The signal is then conditioned (amplified and filtered) Required shaping (for example rectangular

pulse) is obtained using a shape circuit Finally the required signal level is obtained by passing the

resulting signal through a variable-gain amplifier A block diagram of an oscillator illustrating various

stages in the generation of a periodic signal is given in Figure 113

A typical oscillator offers a choice of several (typically six) linear and logarithmic frequency ranges and

a sizable level of control capability (for example 80 dB) Upper and lower frequency limits in a sweep can

be preset on the front panel to any of the available frequency ranges Sweep-rate settings are continuously

DC Voltage

Oscillator

FrequencySpecification

FrequencyConverter

FilterAmplifier

ShaperPeriodicSignal

FrequencyCounter

Fixed-FrequencySignal

Variable-GainOutput

Amplifier

SignalSpecification

LevelSpecification

FIGURE 113 Block diagram of an oscillator-type signal generator

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  • 53191fm
    • Vibration Monitoring Testing and Instrumentation
      • Preface
      • Acknowledgments
      • Editor-in-Chief
      • Contributors
      • Contents
      • Related Titles
          • 53191ch1
            • Table of Contents
            • Chapter 1 Vibration Instrumentation
              • Summary
              • 11 Introduction
              • 12 Vibration Exciters
                • 121 Shaker Selection
                  • 1211 Force Rating
                  • 1212 Power Rating
                  • 1213 Stroke Rating
                  • 1214 Hydraulic Shakers
                  • 1215 Inertial Shakers
                  • 1216 Electromagnetic Shakers
                    • 122 Dynamics of Electromagnetic Shakers
                      • 1221 Transient Exciters
                          • 13 Control System
                            • 131 Components of a Shaker Controller
                              • 1311 Compressor
                              • 1312 Equalizer (Spectrum Shaper)
                              • 1313 Tracking Filter
                              • 1314 Excitation Controller (Amplitude Servo-Monitor)
                                • 132 Signal-Generating Equipment
                                  • 1321 Oscillators
                                  • 1322 Random Signal Generators
                                  • 1323 Tape Players
                                  • 1324 Data Processing
                                      • 14 Performance Specification
                                        • 141 Parameters for Performance Specification
                                          • 1411 Time-Domain Specifications
                                          • 1412 Frequency-Domain Specifications
                                            • 142 Linearity
                                            • 143 Instrument Ratings
                                              • 1431 Rating Parameters
                                                • 144 Accuracy and Precision
                                                  • 15 Motion Sensors and Transducers
                                                    • 151 Potentiometer
                                                      • 1511 Potentiometer Resolution
                                                      • 1512 Optical Potentiometer
                                                        • 152 Variable-Inductance Transducers
                                                          • 1521 Mutual-Induction Transducers
                                                          • 1522 Linear-Variable Differential Transformer
                                                          • 1523 Signal Conditioning
                                                            • 153 Mutual-Induction Proximity Sensor
                                                            • 154 Selfinduction Transducers
                                                            • 155 Permanent-Magnet Transducers
                                                            • 156 Alternating Current Permanent-Magnet Tachometer
                                                            • 157 Alternating Current Induction Tachometer
                                                            • 158 Eddy Current Transducers
                                                            • 159 Variable-Capacitance Transducers
                                                              • 1591 Capacitive Displacement Sensors
                                                              • 1592 Capacitive Angular Velocity Sensor
                                                              • 1593 Capacitance Bridge Circuit
                                                                • 1510 Piezoelectric Transducers
                                                                  • 15101 Sensitivity
                                                                  • 15102 Piezoelectric Accelerometer
                                                                  • 15103 Charge Amplifier
                                                                      • 16 Torque Force and Other Sensors
                                                                        • 161 Strain Gage Sensors
                                                                          • 1611 Equations for Strain Gage Measurements
                                                                          • 1612 Bridge Sensitivity
                                                                          • 1613 The Bridge Constant
                                                                          • 1614 The Calibration Constant
                                                                          • 1615 Data Acquisition
                                                                          • 1616 Accuracy Considerations
                                                                          • 1617 Semiconductor Strain Gages
                                                                          • 1618 Force and Torque Sensors
                                                                          • 1619 Strain Gage Torque Sensors
                                                                          • 16110 Deflection Torque Sensors
                                                                          • 16111 Variable-Reluctance Torque Sensor
                                                                          • 16112 Reaction Torque Sensors
                                                                            • 162 Miscellaneous Sensors
                                                                              • 1621 Stroboscope
                                                                              • 1622 Fiber Optic Sensors and Lasers
                                                                              • 1623 Fiber-Optic Gyroscope
                                                                              • 1624 Laser Doppler Interferometer
                                                                              • 1625 Ultrasonic Sensors
                                                                              • 1626 Gyroscopic Sensors
                                                                                  • References
                                                                                  • Appendix 1A Virtual Instrumentation for Data Acquisition Analysis and Presentation
                                                                                    • Summary
                                                                                    • List of Abbreviations
                                                                                    • 1A1 Dynamic Signals
                                                                                      • 1A11 Acquiring and Simulating Dynamic Signals
                                                                                        • 1A111 Aliasing
                                                                                        • 1A112 Time Continuity
                                                                                            • 1A2 Measurement Configuration Considerations
                                                                                              • 1A21 Input Signal Considerations
                                                                                                • 1A211 Input Pseudodifferential and Differential Configuration
                                                                                                • 1A212 Gain
                                                                                                • 1A213 Input Coupling
                                                                                                • 1A214 Integrated Electronic Piezoelectric Excitation
                                                                                                • 1A215 Nyquist Frequency and Bandwidth
                                                                                                • 1A216 Analog-to-Digital Conversion
                                                                                                • 1A217 Antialias Filters
                                                                                                • 1A218 Input Filter Delay
                                                                                                • 1A219 Overload Detection
                                                                                                  • 1A22 Output Signal Considerations
                                                                                                    • 1A221 Output Pseudodifferential and Differential Configuration
                                                                                                    • 1A222 Attenuation
                                                                                                    • 1A223 Digital-to-Analog Conversion
                                                                                                    • 1A224 Anti-imaging and Interpolation Filters
                                                                                                    • 1A225 Output Filter Delay
                                                                                                        • 1A3 Scaling and Calibration
                                                                                                          • 1A31 Scaling to Engineering Units
                                                                                                          • 1A32 Performing System Calibration
                                                                                                            • 1A321 Propagation Delay Calibration
                                                                                                                • 1A4 Limit Testing Analysis
                                                                                                                  • 1A41 Limit Testing Overview
                                                                                                                  • 1A42 Using the SVT Limit Testing VI
                                                                                                                    • 1A5 Integration
                                                                                                                      • 1A51 Introduction to Integration
                                                                                                                      • 1A52 Implementing Integration
                                                                                                                        • 1A521 Challenges when Integrating Vibration Data
                                                                                                                          • 1A53 Time-Domain Integration
                                                                                                                            • 1A531 Single-Shot Acquisition and Integration
                                                                                                                            • 1A532 Continuous Acquisition and Integration
                                                                                                                              • 1A54 Frequency-Domain Integration
                                                                                                                                • 1A6 Vibration-Level Measurements
                                                                                                                                  • 1A61 Measuring the Root Mean Square Level
                                                                                                                                    • 1A611 Single-Shot Buffered Acquisition
                                                                                                                                    • 1A612 Continuous Signal Acquisition
                                                                                                                                      • 1A62 Performing a Running RMS Level Measurement
                                                                                                                                      • 1A63 Computing the Peak Level
                                                                                                                                      • 1A64 Computing the Crest Factor
                                                                                                                                        • 1A7 Frequency Analysis
                                                                                                                                          • 1A71 FFT Fundamentals
                                                                                                                                            • 1A711 Number of Samples
                                                                                                                                            • 1A712 Frequency Resolution
                                                                                                                                            • 1A713 Maximum Resolvable Frequency
                                                                                                                                            • 1A714 Minimum Resolvable Frequency
                                                                                                                                            • 1A715 Number of Spectral Lines
                                                                                                                                            • 1A716 Relationship between Time-Domain and Frequency-Domain Specifications and Parameters
                                                                                                                                              • 1A72 Increasing Frequency Resolution
                                                                                                                                                • 1A721 Zoom FFT Analysis
                                                                                                                                                • 1A722 Frequency Resolution of the Zoom FFT VIs
                                                                                                                                                • 1A723 Zoom Measurement
                                                                                                                                                • 1A724 Zoom Settings
                                                                                                                                                • 1A725 Subset Analysis
                                                                                                                                                    • 1A8 Transient Analysis
                                                                                                                                                      • 1A81 Transient Analysis with the Sound and Vibration Toolkit
                                                                                                                                                      • 1A82 Performing an STFT vs Time
                                                                                                                                                        • 1A821 Selecting the FFT Block Size
                                                                                                                                                        • 1A822 Overlapping
                                                                                                                                                        • 1A823 Using the SVT STFT vs Time VI
                                                                                                                                                          • 1A83 Performing an STFT vs Rotational Speed
                                                                                                                                                            • 1A831 Converting the Pulse Train to Rotational Speed
                                                                                                                                                            • 1A832 STFT vs RPM
                                                                                                                                                              • 1A84 Measuring a Shock Response Spectrum
                                                                                                                                                                • 1A9 Waterfall Display
                                                                                                                                                                  • 1A91 Using the Display VIs
                                                                                                                                                                    • 1A911 Initializing the Display
                                                                                                                                                                    • 1A912 Sending Data to the Display
                                                                                                                                                                    • 1A913 Waterfall Display for Frequency Analysis
                                                                                                                                                                    • 1A914 Waterfall Display for Transient Analysis
                                                                                                                                                                    • 1A915 Waterfall Display for Octave Spectra
                                                                                                                                                                        • 1A10 Swept-Sine Measurements
                                                                                                                                                                          • 1A101 Swept-Sine Overview
                                                                                                                                                                          • 1A102 Choosing Swept-Sine vs FFT Measurements
                                                                                                                                                                          • 1A103 Taking a Swept-Sine Measurement
                                                                                                                                                                          • 1A104 Swept-Sine Measurement Example
                                                                                                                                                                              • Bibliography
                                                                                                                                                                              • Related Titles
                                                                                                                                                                                  • 53191ch2
                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                    • Chapter 2 Signal Conditioning and Modification
                                                                                                                                                                                      • Summary
                                                                                                                                                                                      • 21 Introduction
                                                                                                                                                                                      • 22 Amplifiers
                                                                                                                                                                                        • 221 Operational Amplifier
                                                                                                                                                                                        • 222 Use of Feedback in Opamp
                                                                                                                                                                                        • 223 Voltage Current and Power Amplifiers
                                                                                                                                                                                          • 2231 Charge Amplifiers
                                                                                                                                                                                            • 224 Instrumentation Amplifiers
                                                                                                                                                                                              • 2241 Differential Amplifier
                                                                                                                                                                                              • 2242 Common Mode
                                                                                                                                                                                                • 225 Amplifier Performance Ratings
                                                                                                                                                                                                  • 2251 Common-Mode Rejection Ratio
                                                                                                                                                                                                    • 226 Component Interconnection
                                                                                                                                                                                                      • 2261 Impedance Characteristics
                                                                                                                                                                                                      • 2262 Cascade Connection of Devices
                                                                                                                                                                                                      • 2263 AC-Coupled Ampliers
                                                                                                                                                                                                          • 23 Analog Filters
                                                                                                                                                                                                            • 231 Passive Filters and Active Filters
                                                                                                                                                                                                              • 2311 Number of Poles
                                                                                                                                                                                                                • 232 Low-Pass Filters
                                                                                                                                                                                                                  • 2321 Low-Pass Butterworth Filter
                                                                                                                                                                                                                    • 233 High-Pass Filters
                                                                                                                                                                                                                    • 234 Band-Pass Filters
                                                                                                                                                                                                                      • 2341 Resonance-Type Band-Pass Filters
                                                                                                                                                                                                                        • 235 Band-Reject Filters
                                                                                                                                                                                                                          • 24 Modulators and Demodulators
                                                                                                                                                                                                                            • 241 Amplitude Modulation
                                                                                                                                                                                                                              • 2411 Modulation Theorem
                                                                                                                                                                                                                              • 2412 Side Frequencies and Side Bands
                                                                                                                                                                                                                                • 242 Application of Amplitude Modulation
                                                                                                                                                                                                                                  • 2421 Fault Detection and Diagnosis
                                                                                                                                                                                                                                    • 243 Demodulation
                                                                                                                                                                                                                                      • 25 Analog ndashDigital Conversion
                                                                                                                                                                                                                                        • 251 Digital-to-Analog Conversion
                                                                                                                                                                                                                                          • 2511 DAC Error Sources
                                                                                                                                                                                                                                            • 252 Analog-to-Digital Conversion
                                                                                                                                                                                                                                            • 253 Analog-to-Digital Converter Performance Characteristics
                                                                                                                                                                                                                                              • 2531 Resolution and Quantization Error
                                                                                                                                                                                                                                              • 2532 Monotonicity Nonlinearity and Offset Error
                                                                                                                                                                                                                                              • 2533 Analog-to-Digital Converter Conversion Rate
                                                                                                                                                                                                                                                • 254 Sample-and-Hold Circuitry
                                                                                                                                                                                                                                                • 255 Digital Filters
                                                                                                                                                                                                                                                  • 2551 Software Implementation and Hardware Implementation
                                                                                                                                                                                                                                                      • 26 Bridge Circuits
                                                                                                                                                                                                                                                        • 261 Wheatstone Bridge
                                                                                                                                                                                                                                                        • 262 Constant-Current Bridge
                                                                                                                                                                                                                                                        • 263 Bridge Amplifiers
                                                                                                                                                                                                                                                          • 2631 Half-Bridge Circuits
                                                                                                                                                                                                                                                            • 264 Impedance Bridges
                                                                                                                                                                                                                                                              • 2641 Owen Bridge
                                                                                                                                                                                                                                                              • 2642 Wien-Bridge Oscillator
                                                                                                                                                                                                                                                                  • 27 Linearizing Devices
                                                                                                                                                                                                                                                                    • 271 Linearization by Software
                                                                                                                                                                                                                                                                    • 272 Linearization by Hardware Logic
                                                                                                                                                                                                                                                                    • 273 Analog Linearizing Circuitry
                                                                                                                                                                                                                                                                    • 274 Offsetting Circuitry
                                                                                                                                                                                                                                                                    • 275 Proportional-Output Circuitry
                                                                                                                                                                                                                                                                      • 2751 Curve-Shaping Circuitry
                                                                                                                                                                                                                                                                          • 28 Miscellaneous Signal Modification Circuitry
                                                                                                                                                                                                                                                                            • 281 Phase Shifters
                                                                                                                                                                                                                                                                            • 282 Voltage-to-Frequency Converter
                                                                                                                                                                                                                                                                            • 283 Frequency-to-Voltage Converter
                                                                                                                                                                                                                                                                            • 284 Voltage-to-Current Converters
                                                                                                                                                                                                                                                                            • 285 Peak-Hold Circuits
                                                                                                                                                                                                                                                                              • 29 Signal Analyzers and Display Devices
                                                                                                                                                                                                                                                                                • 291 Signal Analyzers
                                                                                                                                                                                                                                                                                • 292 Oscilloscopes
                                                                                                                                                                                                                                                                                  • 2921 Triggering
                                                                                                                                                                                                                                                                                  • 2922 Lissajous Patterns
                                                                                                                                                                                                                                                                                  • 2923 Digital Oscilloscopes
                                                                                                                                                                                                                                                                                      • Bibliography
                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                          • 53191ch3
                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                            • Chapter 3 Vibration Testing
                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                              • 31 Introduction
                                                                                                                                                                                                                                                                                              • 32 Representation of a Vibration Environment
                                                                                                                                                                                                                                                                                                • 321 Test Signals
                                                                                                                                                                                                                                                                                                  • 3211 Stochastic vs Deterministic Signals
                                                                                                                                                                                                                                                                                                    • 322 Deterministic Signal Representation
                                                                                                                                                                                                                                                                                                      • 3221 Single-Frequency Signals
                                                                                                                                                                                                                                                                                                      • 3222 Sine Sweep
                                                                                                                                                                                                                                                                                                      • 3223 Sine Dwell
                                                                                                                                                                                                                                                                                                      • 3224 Decaying Sine
                                                                                                                                                                                                                                                                                                      • 3225 Sine Beat
                                                                                                                                                                                                                                                                                                      • 3226 Sine Beat with Pauses
                                                                                                                                                                                                                                                                                                      • 3227 Multifrequency Signals
                                                                                                                                                                                                                                                                                                      • 3228 Actual Excitation Records
                                                                                                                                                                                                                                                                                                      • 3229 Simulated Excitation Signals
                                                                                                                                                                                                                                                                                                        • 323 Stochastic Signal Representation
                                                                                                                                                                                                                                                                                                          • 3231 Ergodic Random Signals
                                                                                                                                                                                                                                                                                                          • 3232 Stationary Random Signals
                                                                                                                                                                                                                                                                                                          • 3233 Independent and Uncorrelated Signals
                                                                                                                                                                                                                                                                                                          • 3234 Transmission of Random Excitations
                                                                                                                                                                                                                                                                                                            • 324 Frequency-Domain Representations
                                                                                                                                                                                                                                                                                                              • 3241 Fourier Spectrum Method
                                                                                                                                                                                                                                                                                                              • 3242 Power Spectral Density Method
                                                                                                                                                                                                                                                                                                                • 325 Response Spectrum
                                                                                                                                                                                                                                                                                                                  • 3251 Displacement Velocity and Acceleration Spectra
                                                                                                                                                                                                                                                                                                                  • 3252 Response-Spectra Plotting Paper
                                                                                                                                                                                                                                                                                                                  • 3253 Zero-Period Acceleration
                                                                                                                                                                                                                                                                                                                  • 3254 Uses of Response Spectra
                                                                                                                                                                                                                                                                                                                    • 326 Comparison of Various Representations
                                                                                                                                                                                                                                                                                                                      • 33 Pretest Procedures
                                                                                                                                                                                                                                                                                                                        • 331 Purpose of Testing
                                                                                                                                                                                                                                                                                                                        • 332 Service Functions
                                                                                                                                                                                                                                                                                                                          • 3321 Active Equipment
                                                                                                                                                                                                                                                                                                                          • 3322 Passive Equipment
                                                                                                                                                                                                                                                                                                                          • 3323 Functional Testing
                                                                                                                                                                                                                                                                                                                            • 333 Information Acquisition
                                                                                                                                                                                                                                                                                                                              • 3331 Interface Details
                                                                                                                                                                                                                                                                                                                              • 3332 Effect of Neglecting Interface Dynamics
                                                                                                                                                                                                                                                                                                                              • 3333 Effects of Damping
                                                                                                                                                                                                                                                                                                                              • 3334 Effects of Inertia
                                                                                                                                                                                                                                                                                                                              • 3335 Effect of Natural Frequency
                                                                                                                                                                                                                                                                                                                              • 3336 Effect of Excitation Frequency
                                                                                                                                                                                                                                                                                                                              • 3337 Other Effects of Interface
                                                                                                                                                                                                                                                                                                                                • 334 Test-Program Planning
                                                                                                                                                                                                                                                                                                                                  • 3341 Testing of Cabinet-Mounted Equipment
                                                                                                                                                                                                                                                                                                                                    • 335 Pretest Inspection
                                                                                                                                                                                                                                                                                                                                      • 34 Testing Procedures
                                                                                                                                                                                                                                                                                                                                        • 341 Resonance Search
                                                                                                                                                                                                                                                                                                                                        • 342 Methods of Determining Frequency-Response Functions
                                                                                                                                                                                                                                                                                                                                          • 3421 Fourier Transform Method
                                                                                                                                                                                                                                                                                                                                          • 3422 Spectral Density Method
                                                                                                                                                                                                                                                                                                                                          • 3423 Harmonic Excitation Method
                                                                                                                                                                                                                                                                                                                                            • 343 Resonance-Search Test Methods
                                                                                                                                                                                                                                                                                                                                              • 3431 Hammer (Bump) Test and Drop Test
                                                                                                                                                                                                                                                                                                                                              • 3432 Pluck Test
                                                                                                                                                                                                                                                                                                                                              • 3433 Shaker Tests
                                                                                                                                                                                                                                                                                                                                                • 344 Mechanical Aging
                                                                                                                                                                                                                                                                                                                                                  • 3441 Equivalence for Mechanical Aging
                                                                                                                                                                                                                                                                                                                                                  • 3442 Excitation-Intensity Equivalence
                                                                                                                                                                                                                                                                                                                                                  • 3443 Dynamic-Excitation Equivalence
                                                                                                                                                                                                                                                                                                                                                  • 3444 Cumulative Damage Theory
                                                                                                                                                                                                                                                                                                                                                    • 345 Test-Response Spectrum Generation
                                                                                                                                                                                                                                                                                                                                                    • 346 Instrument Calibration
                                                                                                                                                                                                                                                                                                                                                    • 347 Test-Object Mounting
                                                                                                                                                                                                                                                                                                                                                    • 348 Test-Input Considerations
                                                                                                                                                                                                                                                                                                                                                      • 3481 Test Nomenclature
                                                                                                                                                                                                                                                                                                                                                      • 3482 Testing with Uncorrelated Excitations
                                                                                                                                                                                                                                                                                                                                                      • 3483 Symmetrical Rectilinear Testing
                                                                                                                                                                                                                                                                                                                                                      • 3484 Geometry vs Dynamics
                                                                                                                                                                                                                                                                                                                                                      • 3485 Some Limitations
                                                                                                                                                                                                                                                                                                                                                      • 3486 Testing Black Boxes
                                                                                                                                                                                                                                                                                                                                                      • 3487 Phasing of Excitations
                                                                                                                                                                                                                                                                                                                                                      • 3488 Testing a Gray or White Box
                                                                                                                                                                                                                                                                                                                                                      • 3489 Overtesting in Multitest Sequences
                                                                                                                                                                                                                                                                                                                                                          • 35 Some Practical Information
                                                                                                                                                                                                                                                                                                                                                            • 351 Random Vibration Test Example
                                                                                                                                                                                                                                                                                                                                                            • 352 Vibration Shakers and Control Systems
                                                                                                                                                                                                                                                                                                                                                              • Bibliography
                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                  • 53191ch4
                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                    • Chapter 4 Experimental Modal Analysis
                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                      • 41 Introduction
                                                                                                                                                                                                                                                                                                                                                                      • 42 Frequency-Domain Formulation
                                                                                                                                                                                                                                                                                                                                                                        • 421 Transfer-Function Matrix
                                                                                                                                                                                                                                                                                                                                                                        • 422 Principle of Reciprocity
                                                                                                                                                                                                                                                                                                                                                                          • 43 Experimental Model Development
                                                                                                                                                                                                                                                                                                                                                                            • 431 Extraction of the Time-Domain Model
                                                                                                                                                                                                                                                                                                                                                                              • 44 Curve Fitting of Transfer Functions
                                                                                                                                                                                                                                                                                                                                                                                • 441 Problem Identification
                                                                                                                                                                                                                                                                                                                                                                                • 442 Single- and Multi-Degree-of-Freedom Techniques
                                                                                                                                                                                                                                                                                                                                                                                • 443 Single-Degree-of-Freedom Parameter Extraction in the Frequency Domain
                                                                                                                                                                                                                                                                                                                                                                                  • 4431 Circle-Fit Method
                                                                                                                                                                                                                                                                                                                                                                                    • Case of Viscous Damping
                                                                                                                                                                                                                                                                                                                                                                                    • Case of Hysteretic Damping
                                                                                                                                                                                                                                                                                                                                                                                      • 4432 Peak-Picking Method
                                                                                                                                                                                                                                                                                                                                                                                        • 444 Multi-Degree of Freedom Curve Fitting
                                                                                                                                                                                                                                                                                                                                                                                          • 4441 Formulation of the Method
                                                                                                                                                                                                                                                                                                                                                                                            • 445 A Comment on Static Modes and Rigid-Body Modes
                                                                                                                                                                                                                                                                                                                                                                                            • 446 Residue Extraction
                                                                                                                                                                                                                                                                                                                                                                                              • 45 Laboratory Experiments
                                                                                                                                                                                                                                                                                                                                                                                                • 451 Lumped-Parameter System
                                                                                                                                                                                                                                                                                                                                                                                                  • 4511 Frequency-Domain Test
                                                                                                                                                                                                                                                                                                                                                                                                  • 4512 Time-Domain Tests
                                                                                                                                                                                                                                                                                                                                                                                                    • 452 Distributed-Parameter System
                                                                                                                                                                                                                                                                                                                                                                                                      • 46 Commercial EMA Systems
                                                                                                                                                                                                                                                                                                                                                                                                        • 461 System Configuration
                                                                                                                                                                                                                                                                                                                                                                                                          • 4611 FFT Analysis Options
                                                                                                                                                                                                                                                                                                                                                                                                          • 4612 Modal Analysis Components
                                                                                                                                                                                                                                                                                                                                                                                                              • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                  • 53191ch5
                                                                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                    • Chapter 5 Mechanical Shock
                                                                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                      • 51 Definitions
                                                                                                                                                                                                                                                                                                                                                                                                                        • 511 Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 512 Simple (or Perfect) Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 513 Half-Sine Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 514 Versed-Sine (or Haversine) Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 515 Terminal Peak Sawtooth Shock or Final Peak Sawtooth Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 516 Rectangular Shock
                                                                                                                                                                                                                                                                                                                                                                                                                          • 5161 Trapezoidal Shock
                                                                                                                                                                                                                                                                                                                                                                                                                              • 52 Description in the Time Domain
                                                                                                                                                                                                                                                                                                                                                                                                                              • 53 Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                • 531 Need
                                                                                                                                                                                                                                                                                                                                                                                                                                • 532 Shock Response Spectrum Definition
                                                                                                                                                                                                                                                                                                                                                                                                                                • 533 Response of a Linear One-Degree-of-Freedom System
                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5331 Shock Defined by a Force
                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5332 Shock Defined by an Acceleration
                                                                                                                                                                                                                                                                                                                                                                                                                                    • 534 Definitions
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5341 Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5342 Absolute Acceleration Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5343 Relative Displacement Shock Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5344 Primary Positive Shock Response Spectrum or Initial Positive Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5345 Primary (or Initial) Negative Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5346 Secondary (or Residual) Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5347 Positive (or Maximum Positive) Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5348 Negative (or Maximum Negative) Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5349 Maximax Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53410 Choice of Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                        • 535 Standardized Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5351 Definition
                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5352 Standardized Shock Response Spectra of Simple Shocks
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53521 Half-Sine Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53522 Versed Sine Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53523 Terminal Peak Sawtooth Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53524 Rectangular Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53525 Trapezoidal Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 536 Choice of Damping
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 537 Shock Response Spectra Domains
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 538 Algorithms for Calculation of the Shock Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 539 Choice of the Digitization Frequency of the Signal
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5310 Use of Shock Response Spectra for the Study of Systems with Several Degrees of Freedom
                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 54 Pyroshocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 55 Use of Shock Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 551 Severity Comparison of Several Shocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 552 Test Specification Development from Real Environment Data
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5521 Synthesis of Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5522 Nature of the Specification
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5523 Choice of Shape
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5524 Amplitude
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5525 Duration
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5526 Difficulties
                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 56 Standards
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 561 Types of Standards
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 562 Installation Conditions of Test Item
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 563 Uncertainty Factor
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 564 Bump Test
                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 57 Damage Boundary Curve
                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 571 Definition
                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 572 Analysis of Test Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 58 Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 581 Main Types
                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 582 Impact Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5821 Universal Shock-Test Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 58211 Impact Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 58212 Impulse Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 583 Shock Simulators (Programmers)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5831 Half-Sine Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58311 Shock Duration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58312 Impact Velocity
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58313 Maximum Deformation of the Shock Simulator (Programmer)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58314 Shock Amplitude
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58315 Characteristics of the Target
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5832 Terminal Peak Sawtooth Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5833 Rectangular Pulse ndash Trapezoidal Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5834 Universal Shock Simulator (Programmer)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 58341 Generating a Half-Sine Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 58342 Generating a Terminal Peak Sawtooth Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 58343 Trapezoidal Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 584 Limitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5841 Limitations of the Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5842 Limitations of Shock Simulators
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 585 Pneumatic Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 586 High Impact Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5861 Lightweight High Impact Shock Machine
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5862 Medium Weight High Impact Shock Machine
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 587 Specific Test Facilities
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 59 Generation of Shock Using Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 591 Principle Behind the Generation of a Simple Shape Signal versus Time
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 592 Main Advantages
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 593 Pre- and Postshocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5931 Requirements
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5932 Solutions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 59321 Optimized Pre- and Postpulses
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5933 Incidence on the Shock Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 594 Limitations of Electrodynamic Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5941 Mechanical Limitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 59411 Abacuses
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5942 Electronic Limitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 595 The Use of Electrohydraulic Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 510 Control by a Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 5101 Principle
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 5102 Principal Shapes of Elementary Signals
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 51021 Decaying Sinusoid
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 51022 ZERD Function
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 51023 WAVSIN Waveform
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 5103 Comparison of WAVSIN SHOC Waveforms and Decaying Sinusoid
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 5104 Criticism of Control by a Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 511 Pyrotechnic Shock Simulation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5111 Simulation Using Pyrotechnic Facilities
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5112 Simulation Using Metal-to-Metal Impact
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5113 Simulation Using Electrodynamic Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5114 Simulation Using Conventional Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53191ch6
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Chapter 6 Machine Condition Monitoring and Fault Diagnostics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 61 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 62 Machinery Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 621 Causes of Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 622 Types of Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 623 Frequency of Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 63 Basic Maintenance Strategies
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 631 Run-to-Failure (Breakdown) Maintenance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 632 Scheduled (Preventative) Maintenance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 633 Condition-Based (Predictive Proactive Reliability Centered On-Condition) Maintenance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 64 Factors Which Influence Maintenance Strategy
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 65 Machine Condition Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 651 Periodic Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 652 Continuous Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 66 Transducer Selection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 661 Noncontact Displacement Transducers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 662 Velocity Transducers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 663 Acceleration Transducers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 67 Transducer Location
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 68 Recording and Analysis Instrumentation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 681 Vibration Meters
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 682 Data Collectors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 683 Frequency-Domain Analyzers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 684 Time-Domain Instruments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 685 Tracking Analyzers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 69 Display Formats and Analysis Tools
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 691 Time Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6911 Time-Waveform Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6912 Time-Waveform Indices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6913 Time-Synchronous Averaging
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6914 Negative Averaging
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6915 Orbits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6916 Probability Density Functions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6917 Probability Density Moments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 692 Frequency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6921 Band-Pass Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6922 Shock Pulse (Spike Energy)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6923 Enveloped Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6924 Signature Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6925 Cascades (Waterfall Plots)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6926 Masks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6927 Frequency-Domain Indices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 693 Modal Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 694 Quefrency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 610 Fault Detection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 6101 Standards
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61011 Standards Based on Machinery Type
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61012 Standards Based on Vibration Severity
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 6102 Acceptance Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 61021 Statistical Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 6103 Frequency-Domain Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61031 Limited Band Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61032 Constant Bandwidth Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61033 Constant Percentage Bandwidth Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 611 Fault Diagnostics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 6111 Forcing Functions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61111 Unbalance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61112 Misalignment
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61113 Mechanical Looseness
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61114 Soft Foot
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61115 Rubs
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61116 Resonances
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61117 Oil Whirl
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61118 Oil Whip
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61119 Structural Vibrations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 611110 Foundation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 6112 Specific Machine Components
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 61121 Damaged or Worn Rolling-Element Bearings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 61122 Damaged or Worn Gears
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 6113 Specific Machine Types
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61131 Pumps
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61132 Fans
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61133 Electric Motors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61134 Steam and Gas Turbines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61135 Compressors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61136 Reciprocating Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 6114 Advanced Fault Diagnostic Techniques
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 53191ch7
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • Chapter 7 Vibration-Based Tool Condition Monitoring Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 71 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 72 Mechanics of Turning
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 721 General Terms
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 722 Chatter Vibrations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 723 Tool Wear
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7231 Tool Failure Mechanisms
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7232 Tool Failure Modes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7233 Tool Wear Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7234 Tool Wear Stages
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 73 Vibration Signal Recording
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 731 Direct and Indirect Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 732 Sensor Requirements for Tool Wear Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 733 Force Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7331 Direct Measurement Dynamometers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7332 Indirect Force Sensors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7333 Piezoelectric Strain Sensors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7334 Resistance Strain Gauges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7335 Customized Force Sensors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 734 Acceleration Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 735 Acoustic Emission Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 736 Sensor Comparisons
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 74 Signal Processing for Sensor-Based Tool Condition Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 741 Feature Extraction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7411 Time Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7412 Frequency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7413 Statistical Processing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7414 TimendashFrequency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 742 Feature Selection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 75 Wear ModelDecision-Making for Sensor-Based Tool Condition Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 751 Trending Threshold
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 752 Neural Networks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7521 Unsupervised Networks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7522 Supervised Networks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 753 Fuzzy Logic
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 754 Other Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 76 Conclusion
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53191ch8
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Chapter 8 Fault Diagnosis of Helicopter Gearboxes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 81 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 82 Abnormality Scaling
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 83 The Structure-Based Connectionist Network
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 84 Sensor Location Selection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 841 Coverage Index
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 842 Overlap Index
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 843 Monitoring Effectiveness
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 85 A Case Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 851 Structural and Featural Influences
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 852 Evaluation of Influences
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 853 Fault Detection Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 854 Fault Diagnostic Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 8541 Faulty Subsystem Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 8542 Faulty Component Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 855 Sensor Location Evaluation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 856 Sensor Location Validation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 86 Conclusion
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 53191ch9
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Chapter 9 Vibration Suppression and Monitoring in Precision Motion Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 91 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 92 Mechanical Design to Minimize Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 921 Stability and Static Determinacy of Machine Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 922 Two-Dimensional Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 923 Three-Dimensional Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 93 Adaptive Notch Filter
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 931 Fast Fourier Transform
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 932 Simulation and Experiments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 94 Real-Time Vibration Analyzer
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 941 Learning Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 942 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 943 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 944 Experiments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 9441 Input Variables mdash the Evaluation Criteria
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 94411 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 94412 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 9442 Evaluation Rules
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 94421 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 94422 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 9443 Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 94431 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 94432 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 95 Practical Insights and Case Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 96 Conclusions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 53191ch10
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Chapter 10 Vibration and Shock Problems of Civil Engineering Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 101 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 102 Earthquake-Induced Vibration of Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1021 Seismicity and Ground Motions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1022 Influence of Local Site Conditions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1023 Response of Structures to Ground Motions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1024 Dynamic Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10241 Equations of Motion for Linear Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10242 Equations of Motion for Linear Multiple-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1025 Earthquake Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10251 Elastic Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10252 Smoothed Design Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10253 Ductility-Modified Response Spectrum Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1026 Design Philosophy and the Code Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10261 Performance-Based Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1027 Analysis Options for Earthquake Effects
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10271 Dynamic Time History Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10272 Response Spectrum Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 102721 Response Spectrum Analysis of Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 102722 Response Spectrum Analysis of Multi-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10273 Equivalent Static Analysis (Force-Based Approach)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10274 Displacement-Based Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1028 SoilndashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1029 Active and Passive Control Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 10210 Worked Examples
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 103 Dynamic Effects of Wind Loading on Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1031 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1032 Wind Speed
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1033 Design Structures for Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10331 Types of Wind Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10332 Design Criteria
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10333 Static Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1034 Along and Across-Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10341 Along-Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10342 Across-Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1035 Wind Tunnel Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1036 Comfort Criteria Human Response to Building Motion
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1037 Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1038 Comparison with Earthquake Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 104 Vibrations Due to Fluid ndashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1041 Added Mass and Inertial Coupling
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1042 Wave-Induced Vibration of Structure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 105 Blast Loading and Blast Effects on Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1051 Explosions and Blast Phenomenon
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1052 Explosive Air-Blast Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10521 Blast Wave Scaling Laws
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10522 Prediction of Blast Pressure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1053 Gas Explosion Loading and Effect of Internal Explosions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1054 Structural Response to Blast Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10541 Elastic Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10542 Elasto-Plastic Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1055 Material Behaviors at High Strain Rate
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10551 Dynamic Properties of Concrete under High Strain Rates
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10552 Dynamic Properties of Reinforcing Steel under High Strain Rates
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1056 Failure Modes of Blast-Loaded Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10561 Global Structural Behavior
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10562 Localized Structural Behavior
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10563 PressurendashImpulse ( PndashI ) Diagrams
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1057 Blast WavendashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1058 Effect of Ground Shocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10581 Loads from Air-Induced Ground Shock
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10582 Loads from Direct Ground Shock
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1059 Technical Design Manuals for Blast-Resistant Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 10510 Computer Programs for Blast and Shock Effects
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 106 Impact Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1061 Structural Impact between Two Bodies mdash Hard Impact and Soft Impact
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1062 Example mdash Aircraft Impact
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 107 Floor Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1071 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1072 Types of Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10721 Walking
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10722 Rhythmic Activities
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10723 Mechanical Equipment
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10724 Analysis Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1073 Natural Frequency of Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10731 Computing the Natural Frequency
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10732 Computing Deflection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10733 Damping
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10734 Resonance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1074 Vibration Caused by Walking
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10741 Minimum Natural Frequency
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1075 Design for Rhythmic Excitation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10751 Harmonics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10752 Minimum Natural Frequency
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1076 Example mdash Vibration Analysis of a Reinforced Concrete Floor
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 53191ch11
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Chapter 11 Seismic Base Isolation and Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 111 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1111 From Ductility Design to Base Isolation and Control Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1112 The Importance of Reducing Seismic Input and Response
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 112 Seismic Base Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1121 Historical Development of Base Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1122 Basic Principle
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1123 Issues in Seismic Base Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11231 Performance Criteria
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11232 Type of Structure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11233 Site Characteristics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11234 Retrofit Issues
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11235 Design of Building Services
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11236 Expected Life of Isolator
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1124 Seismic Isolation Devices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11241 Laminated Rubber Bearings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11242 Lead Rubber Bearing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11243 Friction-Based Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11244 Other Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1125 Design of Isolation Devices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11251 High-Damping Rubber Bearing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112511 Stability against Buckling
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112512 Stability against Roll Out
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11252 Lead Rubber Bearings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112521 Design of Lead Plug
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112522 Design of Laminated Rubber Bearing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11253 Design of Friction Pendulum System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1126 Verification of Properties of Isolation Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11261 Tests for Isolation Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 112611 System Characterization Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 112612 Prototype Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 112613 Quality Control Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11262 Uniform Building Code Recommendations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112621 Units Dependent on Loading Rates
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112622 Units Dependent on Bilateral Load
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112623 System Adequacy
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1127 Analysis of Base-Isolated Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11271 Modeling of a Superstructure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11272 Modeling of Isolation System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11273 Static Analysis Procedure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11274 Dynamic Analysis Procedure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 112741 Response Spectrum Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 112742 Time-History Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11275 Software for Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1128 Experimental Methods for Isolated Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1129 Implementation of Seismic Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11291 New Construction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112911 Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112912 Bridges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11292 Seismic Retrofit
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112921 Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112922 Bridges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11293 Other Implementations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 11210 Performance during Past Earthquakes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 112101 Performance of Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 112102 Performance of Bridges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 113 Seismic Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1131 Historical Development of Seismic Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1132 Basic Principles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11321 Passive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11322 Active Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11323 Semiactive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11324 Hybrid Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11325 Categorization of Basic Principles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1133 Important Issues in Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11331 SoilndashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11332 DevicendashStructure Interaction and Time Delay
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11333 Design Guidelines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1134 Vibration-Control Devices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11341 Passive Control Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113411 Metallic Yielding Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113412 Friction Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113413 Viscoelastic Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113414 Viscous Fluid Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113415 Tuned Mass Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11342 Active Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113421 Electromagnetic Actuator
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113422 Hydraulic Actuators
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11343 Semiactive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113431 Variable-Orifice Hydraulic Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113432 Controllable Fluid Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113433 Controllable Friction Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11344 Hybrid Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1135 Control Algorithm
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11351 Active Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11352 Semiactive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113521 Common Control Schemes for Controllable Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113522 Special Control Schemes for Controllable Damper
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1136 Experimental Performance Verification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11361 Shaking Table Tests of a Flexible Structural Model with TMD AMD and ATMD
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11362 Substructure Hybrid Test
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113621 Hybrid Tests Using Hydraulic Actuator
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113622 Hybrid Tests Using Shaking Table
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113623 Hybrid Tests Using Inertia-Force-Driven Loading System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1137 Implementations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11371 Semiactive Control of Full-Scale Structures Using Variable Joint Damper System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113711 Background of Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113712 Test System Set Up
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113713 Control Algorithm
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113714 Test Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11372 Application of Structural Control Technologies to Seismic Retrofit of a Cable-Stayed Bridge
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113721 Background of Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113722 Basic Concept of Seismic Retrofit
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113723 Modal Shape Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113724 Time-History Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113725 Soil ndash Structure Interaction Effect
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113726 Semiactive Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53191ch12
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Chapter 12 Seismic Random Vibration of Long-Span Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 121 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1211 Basic Concepts of Random Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12111 Stationary Random Process
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12112 Nonstationary Random Process
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1212 Three Methods for Structural Seismic Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12121 Response Spectrum Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12122 Time-History Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12123 Random Vibration Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 121231 Davenport Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 121232 Vanmarcke Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 12124 Comparisons of the Three Seismic-Analysis Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 122 Seismic Random-Excitation Fields
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1221 Power Spectral Density of Spatially Varying Ground Acceleration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1222 Several Coherence Models
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12221 FengndashHu Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12222 Harichandran ndashVanmarcke Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12223 LohndashYeh Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12224 OliveirandashHaondashPenzien Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12225 LucondashWong Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12226 QundashWangndashWang Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1223 Generation of Ground Acceleration Power Spectral Density Curves from Acceleration Response Spectrum Curves
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12231 Kaul Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12232 Iteration Scheme
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1224 Seismic Equations of Motion of Long-Span Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1225 Seismic Waves and Their Geometrical Expressions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 123 Pseudoexcitation Method for Structural Random Vibration Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1231 Structures Subjected to Stationary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12311 Single Stationary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12312 Multiple Stationary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1232 Structures Subjected to Nonstationary Random Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12321 Structures Subjected to Uniformly Modulated Evolutionary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 123211 Single Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 123212 Multiple Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12322 Structures Subjected to Nonuniformly Modulated Evolutionary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 123221 Single Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 123222 Multiple Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1233 Precise Integration Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12331 Precise Integration of Exponential Matrices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12332 Particular Solutions and Precise Integration Formulas for Various Forms of Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 123321 Linear Loading Form (HPD-L Form)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 123322 Sinusoidal Loading Form (HPD-S Form)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 123323 Exponentially Decaying Sinusoidal Loading Form (HPD-E Form)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 124 Long-Span Structures Subjected to Stationary Random Ground Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1241 The Solution of Equations of Motion Using the Pseudoexcitation Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1242 Numerical Comparisons with Other Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12421 Song-Hua-Jiang Suspension Bridge
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 124211 All Supports Move Uniformly
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 124212 Wave Passage Effect Is Taken into Account
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 124213 Wave-Passage Effect and Incoherence Effect Are Jointly Taken into Account
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 12422 San Joaquin Concrete Bridge
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 125 Long-Span Structures Subjected to Nonstationary Random Ground Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1251 Modulation Functions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1252 The Formulas for Nonstationary Multiexcitation Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1253 Expected Extreme Values of Nonstationary Random Processes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1254 Numerical Comparisons with the Corresponding Stationary Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 126 Conclusions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 53191ch13
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Chapter 13 Seismic Qualification of Equipment
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 131 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 132 Distribution Qualification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1321 Drive-Signal Generation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1322 Distribution Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1323 Test Procedures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 133 Seismic Qualification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1331 Stages of Seismic Qualification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1332 Test Preliminaries
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1333 Single-Frequency Testing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1334 Multifrequency Testing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1335 Generation of RRS Specifications
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 53191ch14
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Chapter 14 Human Response to Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 141 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 142 Vibration Excitations on Humans
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1421 Excitation Characteristics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 143 Human Response to Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1431 Vibration Perception
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1432 Frequency Weighting Curve
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1433 Iso-Perception Curves
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1434 Detection Threshold Curve
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 144 Regulation of Human Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1441 Acceptable Vibration Levels in Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1442 Whole-Body Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1443 HandndashArm Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
Page 3: Vibration Monitoring, Testing, and Instrumentationpreview.kingborn.net › 646000 › d1a74678d91943e5ba1d5e... · The MEMS Handbook, Second Edition MEMS: Introduction and Fundamentals

Vibration MonitoringTesting and

Instrumentation

Edited by

Clarence W de SilvaThe University of British Columbia

Vancouver Canada

Ltfi) CRC PressVV^ J Taylor amp Francis Group

Boca Raton London New York

CRC Press is an imprint of theTaylor amp Francis Croup an informa business

copy 2007 by Taylor amp Francis Group LLC

This material was previously published in Vibration and Shock Handbook copy 2005 by CRC Press LLC

CRC PressTaylor amp Francis Group6000 Broken Sound Parkway NW Suite 300Boca Raton FL 33487-2742

copy 2007 by Taylor amp Francis Group LLCCRC Press is an imprint of Taylor amp Francis Group an Informa business

No claim to original US Government worksPrinted in the United States of America on acid-free paper10987654321

International Standard Book Number-101-4200-5319-1 (Hardcover)International Standard Book Number-13978-1-4200-5319-7 (Hardcover)

This book contains information obtained from authentic and highly regarded sources Reprinted material is quotedwith permission and sources are indicated A wide variety of references are listed Reasonable efforts have been made topublish reliable data and information but the author and the publisher cannot assume responsibility for the validity ofall materials or for the consequences of their use

No part of this book may be reprinted reproduced transmitted or utilized in any form by any electronic mechanical orother means now known or hereafter invented including photocopying microfilming and recording or in any informa-tion storage or retrieval system without written permission from the publishers

For permission to photocopy or use material electronically from this work please access wwwcopyrightcom (httpwwwcopyrightcom) or contact the Copyright Clearance Center Inc (CCC) 222 Rosewood Drive Danvers MA 01923978-750-8400 CCC is a not-for-profit organization that provides licenses and registration for a variety of users For orga-nizations that have been granted a photocopy license by the CCC a separate system of payment has been arranged

Trademark Notice Product or corporate names may be trademarks or registered trademarks and are used only foridentification and explanation without intent to infringe

Library of Congress Cataloging-in-Publication Data

Vibration monitoring testing and instrumentation editor Clarence W de Silvap cm mdash (Mechanical engineering series)

Includes bibliographical references and indexISBN-13 978-1-4200-5319-7 (alk paper)ISBN-101-4200-5319-1 (alk paper)1 Vibration 2 Shock (Mechanics) I De Silva Clarence W II Title III Series

TA355V5228 200762030287-dc22 2006100139

Visit the Taylor amp Francis Web site athttpwwwtaylorandfranciscom

and the CRC Press Web site athttpwwwcrcpresscom

copy 2007 by Taylor amp Francis Group LLC

Preface

Individual chapters authored by distinguished leaders and experienced professionals in their

respective topics this book provides for engineers technicians designers researchers educators and

students a convenient thorough up-to-date and authoritative reference source on techniques tools

and data for monitoring testing and instrumentation of mechanical vibration and shock Included

are shock and vibration methodologies particularly for civil and mechanical engineering systems

instrumentation and testing methods including sensors exciters signal acquisition conditioning

and recording and LabVIEWw tools for virtual instrumentation testing and design for seismic

vibration and related regulatory issues and human response to vibration Important information

and results are summarized as windows tables graphs and lists throughout the chapters for easy

reference and information tracking References are given at the end of each chapter for further

information and study Cross-referencing is used throughout to indicate other places in the book

where further information on a particular topic is provided

In the book equal emphasis is given to theory and practical application Analytical

formulations design approaches monitoring and testing techniques and commercial software

tools are presented and illustrated Commercial equipment computer hardware and instrumenta-

tion are described analyzed and demonstrated for field application practical implementation and

experimentation Examples and case studies are given throughout the book to illustrate the use

and application of the included information The material is presented in a format that is

convenient for easy reference and recollection

Mechanical vibration is a manifestation of the oscillatory behavior in mechanical systems as a

result of either the repetitive interchange of kinetic and potential energies among components in

the system or a forcing excitation that is oscillatory Such oscillatory responses are not limited to

purely mechanical systems and are found in electrical and fluid systems as well In purely thermal

systems however free natural oscillations are not possible and an oscillatory excitation is needed

to obtain an oscillatory response Sock is vibration caused by brief abrupt and typically high-

intensity excitations Low levels of vibration mean reduced noise and improved work environment

Consequently a considerable effort is devoted today to monitoring studying and modifying the

vibration and shock generated by machinery components machine tools transit vehicles impact

processes civil engineering structures fluid flow systems and aircraft Before designing a system

for good vibratory or shock performance it is important to understand analyze and represent the

dynamic characteristics of the system This may be accomplished through monitoring testing and

analysis of test data which is the emphasis of this book

In recent years educators researchers and practitioners have devoted considerable effort towards

studying monitoring and testing vibration and shock in a range of applications in various branches

of engineering particularly civil mechanical aeronautical and aerospace and production and

v

53191mdash1432007mdash1850mdashVELUmdash246493mdash CRC ndash pp 1ndash15

copy 2007 by Taylor amp Francis Group LLC

manufacturing Specific applications are found in machine tools transit vehicles impact processes

civil engineering structures construction machinery industrial processes product qualification and

quality control fluid flow systems ships and aircraft This book is a contribution towards these

efforts

Clarence W de SilvaEditor-in-Chief

Vancouver Canada

Prefacevi

53191mdash1432007mdash1850mdashVELUmdash246493mdash CRC ndash pp 1ndash15

copy 2007 by Taylor amp Francis Group LLC

Acknowledgments

I wish to express my gratitude to the authors of the chapters for their valuable and highly professional

contributions I am very grateful to Michael Slaughter Acquisitions Editor-Engineering CRC Press for

his enthusiasm and support throughout the project Editorial and production staff at CRC Press have

done an excellent job in getting this volume out in print Finally I wish to lovingly acknowledge the

patience and understanding of my family

vii

53191mdash1432007mdash1850mdashVELUmdash246493mdash CRC ndash pp 1ndash15

copy 2007 by Taylor amp Francis Group LLC

Editor-in-Chief

Dr Clarence W de Silva PEng Fellow ASME Fellow IEEE Fellow Canadian Academy of

Engineering is Professor of Mechanical Engineering at the University of British Columbia Vancouver

Canada and has occupied the NSERC-BC Packers Research Chair in Industrial Automation since 1988

He has earned PhD degrees from the Massachusetts Institute of Technology and the University of

Cambridge England De Silva has also occupied the Mobil Endowed Chair Professorship in the

Department of Electrical and Computer Engineering at the National University of Singapore He has

served as a consultant to several companies including IBM and Westinghouse in US and has led the

development of eight industrial machines and devices He is recipient of the Henry M Paynter

Outstanding Investigator Award from the Dynamic Systems and Control Division of the American

Society of Mechanical Engineers (ASME) Killam Research Prize Lifetime Achievement Award from the

World Automation Congress Outstanding Engineering Educator Award of IEEE Canada Yasundo

Takahashi Education Award of the Dynamic Systems and Control Division of ASME IEEE Third

Millennium Medal Meritorious Achievement Award of the Association of Professional Engineers of BC

and the Outstanding Contribution Award of the Systems Man and Cybernetics Society of the Institute

of Electrical and Electronics Engineers (IEEE)

He has authored 16 technical books including Sensors and Actuators Control System Instrumentation

(Taylor amp Francis CRC Press 2007) MechatronicsmdashAn Integrated Approach (Taylor amp Francis CRC

Press Boca Raton FL 2005) Soft Computing and Intelligent Systems DesignmdashTheory Tools and

Applications (with F Karry Addison Wesley New York NY 2004) VIBRATION Fundamentals and

Practice (Taylor amp Francis CRC Press 2nd edition 2006) INTELLIGENT CONTROL Fuzzy Logic

Applications (Taylor amp Francis CRC Press 1995) Control Sensors and Actuators (Prentice Hall 1989) 14

edited volumes over 170 journal papers 200 conference papers and 12 book chapters He has served on

the editorial boards of 14 international journals in particular as the Editor-in-Chief of the International

Journal of Control and Intelligent Systems Editor-in-Chief of the International Journal of Knowledge-Based

Intelligent Engineering Systems Senior Technical Editor of Measurements and Control and Regional

Editor North America of Engineering Applications of Artificial Intelligence ndash the International Journal of

Intelligent Real-Time Automation He is a Lilly Fellow at Carnegie Mellon University NASA-ASEE Fellow

Senior Fulbright Fellow at Cambridge University ASI Fellow and a Killam Fellow Research and

development activities of Professor de Silva are primarily centered in the areas of process automation

robotics mechatronics intelligent control and sensors and actuators with cash funding of about $6

million as principal investigator

ix

53191mdash1432007mdash1850mdashVELUmdash246493mdash CRC ndash pp 1ndash15

copy 2007 by Taylor amp Francis Group LLC

Contributors

xi

Kourosh DanaiUniversity of Massachusetts

Amherst Massachusetts

Clarence W de SilvaThe University of British Columbia

Vancouver British Columbia Canada

P S HeynsUniversity of Pretoria

Pretoria South Africa

S HuangNational University of Singapore

Singapore

Hirokazu IemuraKyoto University

Kyoto Japan

Sarvesh Kumar JainMadhav Institute of Technology and

Science

Madhya Pradesh India

Christian LalanneEngineering Consultant

Jalles France

TH LeeNational University of Singapore

Singapore

YP LeowSingapore Institute of Manufacturing

Technology

Singapore

SY LimSingapore Institute of Manufacturing

Technology

Singapore

Jiaohao LinDalian University of Technology

Liaoning Peoplersquos Republic of China

W LinSingapore Institute of Manufacturing

Technology

Singapore

Chris K MechefskeQueenrsquos University

Kingston Ontario Canada

Priyan MendisUniversity of Melbourne

Melbourne Victoria Australia

Tuan NgoUniversity of Melbourne

Melbourne Victoria Australia

Mulyo Harris PradonoKyoto University

Kyoto Japan

C SchefferUniversity of Stellenbosch

Pretoria South Africa

KK TanNational University of Singapore

Singapore

KZ TangNational University of Singapore

Singapore

Yahui ZhangDalian University of Technology

Liaoning Peoplersquos Republic of China

53191mdash1432007mdash1850mdashVELUmdash246493mdash CRC ndash pp 1ndash15

copy 2007 by Taylor amp Francis Group LLC

Contents

1 Vibration Instrumentation Clarence W de Silva 1-1

11 Introduction 1-1

12 Vibration Exciters 1-3

13 Control System 1-15

14 Performance Specification 1-21

15 Motion Sensors and Transducers 1-27

16 Torque Force and Other Sensors 1-50

Appendix 1A Virtual Instrumentation for Data Acquisition Analysis

and Presentation 1-73

2 Signal Conditioning and Modification Clarence W de Silva 2-1

21 Introduction 2-2

22 Amplifiers 2-2

23 Analog Filters 2-15

24 Modulators and Demodulators 2-29

25 AnalogndashDigital Conversion 2-37

26 Bridge Circuits 2-43

27 Linearizing Devices 2-49

28 Miscellaneous Signal Modification Circuitry 2-56

29 Signal Analyzers and Display Devices 2-62

3 Vibration Testing Clarence W de Silva 3-1

31 Introduction 3-1

32 Representation of a Vibration Environment 3-3

33 Pretest Procedures 3-24

34 Testing Procedures 3-37

35 Some Practical Information 3-52

4 Experimental Modal Analysis Clarence W de Silva 4-1

41 Introduction 4-1

42 Frequency-Domain Formulation 4-2

43 Experimental Model Development 4-8

44 Curve Fitting of Transfer Functions 4-10

45 Laboratory Experiments 4-18

46 Commercial EMA Systems 4-24

xiii

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copy 2007 by Taylor amp Francis Group LLC

5 Mechanical Shock Christian Lalanne 5-1

51 Definitions 5-2

52 Description in the Time Domain 5-3

53 Shock Response Spectrum 5-4

54 Pyroshocks 5-17

55 Use of Shock Response Spectra 5-18

56 Standards 5-24

57 Damage Boundary Curve 5-26

58 Shock Machines 5-28

59 Generation of Shock Using Shakers 5-44

510 Control by a Shock Response Spectrum 5-52

511 Pyrotechnic Shock Simulation 5-58

6 Machine Condition Monitoring and Fault Diagnostics Chris K Mechefske 6-1

61 Introduction 6-2

62 Machinery Failure 6-2

63 Basic Maintenance Strategies 6-4

64 Factors Which Influence Maintenance Strategy 6-7

65 Machine Condition Monitoring 6-8

66 Transducer Selection 6-10

67 Transducer Location 6-14

68 Recording and Analysis Instrumentation 6-14

69 Display Formats and Analysis Tools 6-16

610 Fault Detection 6-21

611 Fault Diagnostics 6-25

7 Vibration-Based Tool Condition Monitoring Systems C Scheffer and PS Heyns 7-1

71 Introduction 7-1

72 Mechanics of Turning 7-2

73 Vibration Signal Recording 7-7

74 Signal Processing for Sensor-Based Tool Condition Monitoring 7-11

75 Wear ModelDecision-Making for Sensor-Based Tool Condition Monitoring 7-15

76 Conclusion 7-20

8 Fault Diagnosis of Helicopter Gearboxes Kourosh Danai 8-1

81 Introduction 8-1

82 Abnormality Scaling 8-5

83 The Structure-Based Connectionist Network 8-8

84 Sensor Location Selection 8-11

85 A Case Study 8-14

86 Conclusion 8-23

9 Vibration Suppression and Monitoring in Precision Motion Systems KK Tan

TH Lee KZ Tang S Huang SY Lim W Lin and YP Leow 9-1

91 Introduction 9-1

92 Mechanical Design to Minimize Vibration 9-2

93 Adaptive Notch Filter 9-10

94 Real-Time Vibration Analyzer 9-17

Contentsxiv

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copy 2007 by Taylor amp Francis Group LLC

95 Practical Insights and Case Study 9-29

96 Conclusions 9-35

10 Vibration and Shock Problems of Civil Engineering Structures Priyan Mendis

and Tuan Ngo 10-1

101 Introduction 10-2

102 Earthquake-Induced Vibration of Structures 10-3

103 Dynamic Effects of Wind Loading on Structures 10-22

104 Vibrations Due to FluidndashStructure Interaction 10-33

105 Blast Loading and Blast Effects on Structures 10-34

106 Impact Loading 10-47

107 Floor Vibration 10-51

11 Seismic Base Isolation and Vibration Control Hirokazu Iemura Sarvesh Kumar Jain

and Mulyo Harris Pradono 11-1

111 Introduction 11-1

112 Seismic Base Isolation 11-4

113 Seismic Vibration Control 11-33

12 Seismic Random Vibration of Long-Span Structures Jiahao Lin and Yahui Zhang 12-1

121 Introduction 12-2

122 Seismic Random-Excitation Fields 12-11

123 Pseudoexcitation Method for Structural Random Vibration Analysis 12-16

124 Long-Span Structures Subjected to Stationary Random Ground Excitations 12-27

125 Long-Span Structures Subjected to Nonstationary Random Ground Excitations 12-34

126 Conclusions 12-39

13 Seismic Qualification of Equipment Clarence W de Silva 13-1

131 Introduction 13-1

132 Distribution Qualification 13-1

133 Seismic Qualification 13-6

14 Human Response to Vibration Clarence W de Silva 14-1

141 Introduction 14-1

142 Vibration Excitations on Humans 14-2

143 Human Response to Vibration 14-3

144 Regulation of Human Vibration 14-6

Contents xv

53191mdash1432007mdash1850mdashVELUmdash246493mdash CRC ndash pp 1ndash15

copy 2007 by Taylor amp Francis Group LLC

1Vibration

Instrumentation

Clarence W de SilvaThe University of British Columbia

11 Introduction 1-1

12 Vibration Exciters 1-3Shaker Selection dagger Dynamics of Electromagnetic Shakers

13 Control System 1-15Components of a Shaker Controller dagger Signal-Generating

Equipment

14 Performance Specification 1-21Parameters for Performance Specification dagger Linearity dagger

Instrument Ratings dagger Accuracy and Precision

15 Motion Sensors and Transducers 1-27Potentiometer dagger Variable-Inductance Transducers dagger

Mutual-Induction Proximity Sensor dagger Selfinduction

Transducers dagger Permanent-Magnet Transducers dagger

Alternating Current Permanent-Magnet Tachometer dagger

Alternating Current Induction Tachometer dagger Eddy Current

Transducers dagger Variable-Capacitance Transducers dagger

Piezoelectric Transducers

16 Torque Force and Other Sensors 1-50Strain Gage Sensors dagger Miscellaneous Sensors

Appendix 1A Virtual Instrumentation for DataAcquisition Analysis and Presentation 1-73

Summary

Devices useful in instrumenting a mechanical vibrating system are presented in this chapter Shakers whichgenerate vibration excitations are discussed and compared A variety of sensors including motion sensorsproximity sensors forcetorque sensors and other miscellaneous sensors are considered Performance specificationin the time domain and the frequency domain is addressed Rating parameters of instruments are given

11 Introduction

Measurement and associated experimental techniques play a significant role in the practice of vibration

Academic exposure to vibration instrumentation usually arises in laboratories in the context of learning

training and research In vibration practice perhaps the most important task of instrumentation is the

measurement or sensing of vibration Vibration sensing is useful in the following applications

1 Design and development of a product

2 Testing (screening) of a finished product for quality assurance

3 Qualification of a good-quality product to determine its suitability for a specific application

1-1

53191mdash522007mdash1201mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

4 Mechanical aging of a product prior to carrying out a test program

5 Exploratory testing of a product to determine its dynamic characteristics such as resonances

mode shapes and even a complete dynamic model

6 Vibration monitoring for performance evaluation

7 Control and suppression of vibration

Figure 11 indicates a procedure typical of experimental vibration highlighting the essential

instrumentation Vibrations are generated in a device the test object in response to some excitation In

some experimental procedures primarily in vibration testing (see Figure 11) the excitation signal has

to be generated in a signal generator in accordance with some requirement (specification) and applied to

the object through an exciter after amplification and conditioning In some other situations primarily in

performance monitoring and vibration control the excitations are generated as an integral part of the

operating environment of the vibrating object and may originate either within the object (eg engine

excitations in an automobile) or in the environment with which the object interacts during operation

(eg road disturbances on an automobile) Sensors are needed to measure vibrations in the test object In

particular a control sensor is used to check whether the specified excitation is applied to the object

and one or more response sensors may be used to measure the resulting vibrations at key locations of

the object

The sensor signals have to be properly conditioned for example by filtering and amplification and

modified for example through modulation demodulation and analog-to-digital conversion prior to

recording analyzing and display The purpose of the controller is to guarantee that the excitation is

correctly applied to the test object If the signal from the control sensor deviates from the required

excitation the controller modifies the signal to the exciter so as to reduce this deviation Furthermore the

controller will stabilize or limit (compress) the vibrations in the object It follows that instruments in

experimental vibration may be generally classified into the following categories

1 Signal-generating devices

2 Vibration exciters

3 Sensors and transducers

4 Signal conditioningmodifying devices

5 Signal analysis devices

6 Control devices

7 Vibration recording and display devices

AnalogDigital

Interface

DigitalSignal

RecorderAnalyzerDisplay

FilterAmplifier

FilterAmplifier

SignalGenerator

and ExciterController

Reference (Required)Signal (Specification)

PowerAmplifier

MountingFixtures

TestObject

ResponseSensor

ControlSensor

Exciter

SwivelBase

FIGURE 11 Typical instrumentation in experimental vibration

Vibration Monitoring Testing and Instrumentation1-2

53191mdash522007mdash1201mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

Note that one instrument may perform the tasks

of more than one category listed here Also more

than one instrument may be needed to carry out

tasks in a single category In the following sections

we will provide some examples of the types of

vibration instrumentation giving characteristics

operating principles and important practical

considerations Also we will describe several

experiments which can be found in a typical

vibration laboratory

An experimental vibration system generally

consists of four main subsystems

1 Test object

2 Excitation system

3 Control system

4 Signal acquisition and modification system

These are schematically shown in Figure 12 Note that various components shown in Figure 11 may

be incorporated into one of these subsystems In particular component matching hardware and object

mounting fixtures may be considered interfacing devices that are introduced through the interaction

between the main subsystems as shown in Figure 12 Some important issues of vibration testing and

instrumentation are summarized in Box 11

12 Vibration Exciters

Vibration experimentation may require an external exciter to generate the necessary vibration This is the

case in controlled experiments such as product testing where a specified level of vibration is applied to the

test object and the resulting response is monitored A variety of vibration exciters are available with

different capabilities and principles of operation

Three basic types of vibration exciters (shakers) are widely used hydraulic shakers inertial shakers

and electromagnetic shakers The operation-capability ranges of typical exciters in these three categories

are summarized in Table 11 Stroke or maximum displacement is the largest displacement the exciter

is capable of imparting onto a test object whose weight is assumed to be within its design load limit

Maximum velocity and acceleration are similarly defined Maximum force is the largest force that could

be applied by the shaker to a test object of acceptable weight (one within the design load) The values

given in Table 11 should be interpreted with caution Maximum displacement is achieved only at very

low frequencies The achievement of maximum velocity corresponds to intermediate frequencies in the

operating frequency range of the shaker Maximum acceleration and force ratings are usually achieved at

high frequencies It is not feasible for example to operate a vibration exciter at its maximum

displacement and its maximum acceleration simultaneously

Consider a loaded exciter that is executing harmonic motion Its displacement is given by

x frac14 s sin vt eth11THORN

in which s is the displacement amplitude (or stroke) Corresponding velocity and acceleration are

_x frac14 sv cos vt eth12THORN

eurox frac14 2sv2sin vt eth13THORN

SignalModification

System

TestObject

ControlSystem

VibrationExciter (Shaker)

System

FIGURE 12 Interactions between major subsystems of

an experimental vibration system

Vibration Instrumentation 1-3

53191mdash522007mdash1201mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

If the velocity amplitude is denoted by v and the acceleration amplitude by a it follows from Equation

12 and Equation 13 thatv frac14 vs eth14THORN

and

a frac14 vv eth15THORN

Box 11

VIBRATION INSTRUMENTATION

Vibration Testing Applications for Products

Design and Development Production Screening and Quality Assessment Utilization and Qualification for Special Applications

Testing Instrumentation

Exciter (excites the test object) Controller (controls the exciter for accurate excitation) Sensors and Transducers (measure excitations and responses and provide excitation error

signals to controller) Signal Conditioning (converts signals to appropriate form) Recording and Display (perform processing storage and documentation)

Exciters

Shakers

1 Electrodynamic (high bandwidth moderate power complex and multifrequency

excitations)

2 Hydraulic (moderate to high bandwidth high power complex and multifrequency

excitations)

3 Inertial (low bandwidth low power single-frequency harmonic excitations)

TransientInitial Condition

1 Hammers (impulsive bump tests)

2 Cable Release (step excitations)

3 Drop (impulsive)

Signal Conditioning

Filters Amplifiers Amplifiers ModulatorsDemodulators ADCDAC

Sensors

Motion (displacement velocity acceleration) Force (strain torque)

Vibration Monitoring Testing and Instrumentation1-4

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copy 2007 by Taylor amp Francis Group LLC

TABLE 11 Typical Operation-Capability Ranges for Various Shaker Types

Shaker Type Typical Operational Capabilities

Frequency Maximum Displacement

(Stroke)

Maximum

Velocity

Maximum

Acceleration

Maximum

Force

Excitation

Waveform

Hydraulic

(electrohydraulic)

Low

(01ndash500 Hz)

High (20 in 50 cm) Intermediate

(50 insec

125 cmsec)

Intermediate

(20 g)

High (100000 lbf

450000 N)

Average flexibility (simple

to complex and random)

Inertial

(counter-rotating mass)

Intermediate

(2ndash50 Hz)

Low (1 in 25 cm) Intermediate

(50 insec

125 cmsec)

Intermediate

(20 g)

Intermediate

(1000 lbf 4500 N)

Sinusoidal only

Electromagnetic

(electrodynamic)

High

(2ndash10000 Hz)

Low (1 in 25 cm) Intermediate

(50 insec

125 cmsec)

High (100 g) Low to intermediate

(450 lbf 2000 N)

High flexibility and accuracy

(simple to complex and

random)

VibrationInstru

mentation

1-5

53191mdash522007mdash

1201mdashSENTHILKUMARmdash246494mdash

CRCndashpp1ndash112

copy 2007 by Taylor amp Francis Group LLC

An idealized performance curve of a shaker

has a constant displacementndashamplitude region a

constant velocityndashamplitude region and a con-

stant accelerationndashamplitude region for low

intermediate and high frequencies respectively

in the operating frequency range Such an ideal

performance curve is shown in Figure 13(a) on a

frequencyndashvelocity plane Logarithmic axes are

used In practice typical shaker performance

curves would be fairly smooth yet nonlinear

curves similar to those shown in Figure 13(b)

As the mass increases the performance curve

compresses Note that the acceleration limit of a

shaker depends on the mass of the test object

(load) Full load corresponds to the heaviest object

that could be tested The ldquono loadrdquo condition

corresponds to a shaker without a test object To

standardize the performance curves they are

usually defined at the rated load of the shaker A

performance curve in the frequencyndashvelocity

plane may be converted to a curve in the

frequencyndashacceleration plane simply by increasing

the slope of the curve by a unit magnitude (ie

20 dbdecade)

Several general observations can be made from

Equation 14 and Equation 15 In the constant-

peak displacement region of the performance

curve the peak velocity increases proportionally

with the excitation frequency and the peak

acceleration increases with the square of the excitation frequency In the constant-peak velocity region

the peak displacement varies inversely with the excitation frequency and the peak acceleration increases

proportionately In the constant-peak acceleration region the peak displacement varies inversely with the

square of the excitation frequency and the peak velocity varies inversely with the excitation frequency

This further explains why rated stroke maximum velocity and maximum acceleration values are not

simultaneously realized

121 Shaker Selection

Vibration testing is accomplished by applying a specified excitation to the test package using a shaker

apparatus and monitoring the response of the test object Test excitation may be represented by its

response spectrum The test requires that the response spectrum of the actual excitation known as the

test response spectrum (TRS) envelops the response spectrum specified for the particular test known as

the required response spectrum (RRS)

A major step in the planning of any vibration testing program is the selection of a proper shaker

(exciter) system for a given test package The three specifications that are of primary importance in

selecting a shaker are the force rating the power rating and the stroke (maximum displacement) rating

Force and power ratings are particularly useful in moderate to high frequency excitations and the stroke

rating is the determining factor for low frequency excitations In this section a procedure is given to

determine conservative estimates for these parameters in a specified test for a given test package

Frequency domain considerations are used here

Stroke

Limit M

ax

Acceleration

MaxVelocity

Peak

Vel

ocity

(cm

s)

01 1 10 100

FullLoad

NoLoad

Frequency (Hz)(a)

Peak

Vel

ocity

(cm

s)

100

10

1

100

10

1

01 1 10 100

FullLoad

NoLoad

Frequency (Hz)(b)

FIGURE 13 Performance curve of a vibration exciter

in the frequencyndashvelocity plane (log) (a) ideal (b)

typical

Vibration Monitoring Testing and Instrumentation1-6

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copy 2007 by Taylor amp Francis Group LLC

1211 Force Rating

In the frequency domain the (complex) force at the exciter (shaker) head is given by

F frac14 mHethvTHORNasethvTHORN eth16THORNin which v is the excitation frequency variable m is the total mass of the test package including

mounting fixture and attachments asethvTHORN is the Fourier spectrum of the support-location (exciter head)

acceleration and H(v) is frequency response function that takes into account the flexibility and

damping effects (dynamics) of the test package apart from its inertia In the simplified case where the

test package can be represented by a simple oscillator of natural frequency vn and damping ratio by zt

this function becomes

HethvTHORN frac14 1thorn 2jztv=vn=12 ethv=vnTHORN2 thorn 2jztv=vn eth17THORNin which j frac14 ffiffiffiffi

21p

This approximation is adequate for most practical purposes The static weight of the

test object is not included in Equation 16 Most heavy-duty shakers which are typically hydraulic

have static load support systems such as pneumatic cushion arrangements that can exactly balance the

dead load The exciter provides only the dynamic force In cases where shaker directly supports the

gravity load in the vertical test configuration Equation 16 should be modified by adding a term to

represent this weight

A common practice in vibration test applications is to specify the excitation signal by its response

spectrum This is simply the peak response of a simple oscillator expressed as a function of its natural

frequency when its support location is excited by the specified signal Clearly the damping of the simple

oscillator is an added parameter in a response spectrum specification Typical damping ratios ethzrTHORN used inresponse spectra specifications are less than 01 (or 10) It follows that an approximate relationship

between the Fourier spectrum of the support acceleration and its response spectrum is

as frac14 2jzrarethvTHORN eth18THORNThe magnitude larethvTHORNl is the response spectrumEquation 18 substituted into Equation 16 gives

F frac14 mHethvTHORN2jzrarethvTHORN eth19THORNIn view of Equation 17 for test packages having low damping the peak value of H(v) is

approximately 1=eth2jztTHORN this should be used in computing the force rating if the test package has a

resonance within the frequency range of testing On the other hand if the test package is assumed to be

rigid then HethvTHORN oslash 1 A conservative estimate for the force rating is

Fmax frac14 methzr=ztTHORNlarethvTHORNlmax eth110THORNIt should be noted that larethvTHORNlmax is the peak value of the specified (required) response spectrum (RRS)

for acceleration

1212 Power Rating

The exciter head does not develop its maximum force when driven at maximum velocity Output power

is determined by using

p frac14 Refrac12FvsethvTHORN eth111THORNin which vsethvTHORN is the Fourier spectrum of the exciter velocity and Re [ ] denotes the real part of a complex

function Note that as frac14 jvvs Substituting Equation 16 and Equation 18 into Equation 111 gives

p frac14 eth4mz2r =vTHORNRefrac12jHethvTHORNa2r ethvTHORN eth112THORNIt follows that a conservative estimate for the power rating is

pmax frac14 2methz2r =ztTHORNfrac12larethvTHORNl2=v max eth113THORN

Vibration Instrumentation 1-7

53191mdash522007mdash1201mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

Representative segments of typical acceleration RRS curves have slope n as given by

a frac14 k1vn eth114THORN

It should be clear from Equation 113 that the maximum output power is given by

pmax frac14 k2v2n21 eth115THORN

This is an increasing function for n 1=2 and a decreasing function for n 1=2 It follows that the power

rating corresponds to the highest point of contact between the acceleration RRS curve and a line of slope

equal to 12 A similar relationship may be derived if velocity RRS curves (having slopes n2 1) are used

1213 Stroke Rating

From Equation 18 it should be clear that the Fourier spectrum xs of the exciter displacement time

history can be expressed as

xs frac14 2zrarethvTHORN=jv2 eth116THORNAn estimate for stroke rating is

xmax frac14 2zrfrac12larethvTHORNl=v2 max eth117THORNThis is of the form

xmax frac14 kvn22 eth118THORNIt follows that the stroke rating corresponds to the highest point of contact between the acceleration

RRS curve and a line of slope equal to two

Example 11

A test package of overall mass 100 kg is to be

subjected to dynamic excitation represented by the

acceleration RRS (at 5 damping) as shown in

Figure 14 The estimated damping of the test

package is 7 The test package is known to have a

resonance within the frequency range of the

specified test Determine the exciter specifications

for the test

Solution

From the development presented in the previous

section it is clear that the point F (or P) in

Figure 14 corresponds to the force and output

power ratings and the point S corresponds to

the stroke rating The co-ordinates of these

critical points are F P frac14 eth42 Hz 40 gTHORN and S frac14 eth08 Hz 075 gTHORN Equation 110 gives the force

rating as

Fmax frac14 100 pound eth005=007THORN pound 40 pound 981 N frac14 2803 N

Equation 113 gives the power rating as

pmax frac14 2 pound 100 pound eth0052=007THORN pound frac12eth40 pound 981THORN2=42 pound 2p watts frac14 417 W

Equation 117 gives the stroke rating as

xmax frac14 2 pound 005 pound frac12eth075 pound 98THORN=eth08 pound 2pTHORN2 m frac14 3 cm

Acc

eler

atio

n(g

)

Con

stan

t Dis

plac

emen

t

Constant Velo

city

Frequency (Hz)

S

FP

0101

10 10 100

10

10

FIGURE 14 Test excitation specified by an accelera-

tion RRS (5 damping)

Vibration Monitoring Testing and Instrumentation1-8

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copy 2007 by Taylor amp Francis Group LLC

1214 Hydraulic Shakers

A typical hydraulic shaker consists of a piston-cylinder arrangement (also called a ram) a servo-valve a

fluid pump and a driving electric motor Hydraulic fluid (oil) is pressurized (typical operating pressure

4000 psi) and pumped into the cylinder through a servo-valve by means of a pump that is driven by an

electric motor (typical power 150 hp) The flow (typical rate 100 galmin) that enters the cylinder is

controlled (modulated) by the servo-valve which in effect controls the resulting piston (ram) motion

A typical servo-valve consists of a two-stage spool valve which provides a pressure difference and a

controlled (modulated) flow to the piston which sets it in motion

The servo-valve itself is moved by means of a linear torque motor which is driven by the excitation-

input signal (electrical) A primary function of the servo-valve is to provide a stabilizing feedback to the

ram In this respect the servo-valve complements the main control system of the test setup The ram is

coupled to the shaker table by means of a link with some flexibility The cylinder frame is mounted on the

support foundation with swivel joints This allows for some angular and lateral misalignment which

might be caused primarily by test-object dynamics as the table moves

Two-degree-of-freedom (Two-DoF) testing requires two independent sets of actuators and three-DoF

testing requires three independent actuator sets Each independent actuator set can consist of several

actuators operated in parallel using the same pump and the same excitation-input signal to the torque

motors

If the test table is directly supported on the vertical actuators they must withstand the total dead

weight (ie the weight of the test table the test object the mounting fixtures and the instrumentation)

This is requirement is usually prevented by providing a pressurized air cushion in the gap between the

test table and the foundation walls Air should be pressurized so as to balance the total dead weight

exactly (typical required gage pressure 3 psi)

Figure 15(a) shows the basic components of a typical hydraulic shaker The corresponding

operational block diagram is shown in Figure 15(b) It is desirable to locate the actuators in a pit in the

test laboratory so that the test tabletop is flushed with the test laboratory floor under no-load conditions

This minimizes the effort required to place the test object on the test table Otherwise the test object has

to be lifted onto the test table with a forklift Also installation of an aircushion to support the system

dead weight is difficult under these circumstances of elevated mounting

Hydraulic actuators are most suitable for heavy load testing and are widely used in industrial and civil

engineering applications They canbeoperated at very low frequencies (almost direct current [DC]) aswell

as at intermediate frequencies (see Table 11) Large displacements (stroke) are possible at low frequencies

Hydraulic shakers have the advantage of providing high flexibility of operation during the test their

capabilities include variable-force and constant-force testing and wide-band random-input testing The

velocity and acceleration capabilities of hydraulic shakers are moderate Although any general excitation-

input motion (for example sine wave sine beat wide-band random) can be used in hydraulic shakers

faithful reproduction of these signals is virtually impossible at high frequencies because of distortion and

higher-order harmonics introduced by the high noise levels that are common in hydraulic systems This

is only a minor drawback in heavy-duty intermediate-frequency applications Dynamic interactions are

reduced through feedback control

1215 Inertial Shakers

In inertial shakers or ldquomechanical excitersrdquo the force that causes the shaker-table motion is generated by

inertia forces (accelerating masses) Counter-rotating-mass inertial shakers are typical in this category

To understand their principle of operation consider two equal masses rotating in opposite directions at

the same angular speed v and in the same circle of radius r (see Figure 16) This produces a resultant

force equal to 2mv2r cos vt in a fixed direction (the direction of symmetry of the two rotating arms)

Consequently a sinusoidal force with a frequency of v and an amplitude proportional to v2 is generated

This reaction force is applied to the shaker table

Figure 17 shows a sketch of a typical counter-rotating-mass inertial shaker It consists of two identical

rods rotating at the same speed in opposite directions Each rod has a series of slots in which to

Vibration Instrumentation 1-9

53191mdash522007mdash1201mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

place weights In this manner the magnitude of

the eccentric mass can be varied to achieve various

force capabilities The rods are driven by a

variable-speed electric motor through a gear

mechanism that usually provides several speed

ratios A speed ratio is selected depending on the

required test-frequency range The whole system is

symmetrically supported on a carriage that is

directly connected to the test table The test object

is mounted on the test table The preferred

mounting configuration is horizontal so that the

excitation force is applied to the test object in a

horizontal direction In this configuration there

are no variable gravity moments (weight pounddistance to center of gravity) acting on the drive

mechanism Figure 17 shows the vertical con-

figuration In dynamic testing of large structures

the carriage can be mounted directly on the

structure at a location where the excitation force

should be applied By incorporating two pairs of

counter-rotating masses it is possible to generate

test moments as well as test forces

FIGURE 15 A typical hydraulic shaker arrangement (a) schematic diagram (b) operational block diagram

m m

2mw2r cos wt

wtw w

wt

FIGURE 16 Principle of operation of a counter-

rotating-mass inertial shaker

Vibration Monitoring Testing and Instrumentation1-10

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copy 2007 by Taylor amp Francis Group LLC

Reaction-type shakers driven by inertia are widely used for the prototype testing of civil engineering

structures Their first application dates back to 1935 Inertial shakers are capable of producing

intermediate excitation forces The force generated is limited by the strength of the carriage frame The

frequency range of operation and the maximum velocity and acceleration capabilities are also

intermediate for inertial shakers whereas the maximum displacement capability is typically low A major

limitation of inertial shakers is that their excitation force is exclusively sinusoidal and that the force

amplitude is directly proportional to the square of the excitation frequency As a result complex and

random excitation testing constant-force testing (for example transmissibility tests and constant-force

sine-sweep tests) and flexibility to vary the force amplitude or the displacement amplitude during a test

are not generally feasible with this type of shakers Excitation frequency and amplitude can be varied

during testing however by incorporating a variable-speed drive for the motor The sinusoidal excitation

generated by inertial shakers is virtually undistorted which gives them an advantage over the other types

of shakers when used in sine-dwell and sine-sweep tests Small portable shakers with low-force capability

are available for use in on-site testing

1216 Electromagnetic Shakers

In electromagnetic shakers or ldquoelectrodynamic excitersrdquo the motion is generated using the principle of

operation of an electric motor Specifically the excitation force is produced when a variable excitation

signal (electrical) is passed through a moving coil placed in a magnetic field

The components of a commercial electromagnetic shaker are shown in Figure 18 A steady magnetic

field is generated by a stationary electromagnet that consists of field coils wound on a ferromagnetic base

that is rigidly attached to a protective shell structure The shaker head has a coil wound around it When

the excitation electrical signal is passed through this drive coil the shaker head which is supported on

flexure mounts will be set in motion The shaker head consists of the test table on which the test object

is mounted Shakers with interchangeable heads are available The choice of appropriate shaker head is

based on the geometry and mounting features of the test object The shaker head can be turned to

different angles by means of a swivel joint In this manner different directions of excitation (in biaxial

and triaxial testing) can be obtained

FIGURE 17 Sketch of a counter-rotating-mass inertial shaker

Vibration Instrumentation 1-11

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copy 2007 by Taylor amp Francis Group LLC

122 Dynamics of Electromagnetic Shakers

Consider a single axis electromagnetic shaker (Figure 18) with a test object having a single natural

frequency of importance within the test frequency range The dynamic interactions between the shaker

and the test object give rise to two significant natural frequencies (and correspondingly two significant

resonances) These appear as peaks in the frequency response curve of the test setup Furthermore the

natural frequency (resonance) of the test package alone causes a ldquotroughrdquo or depression (antiresonance)

in the frequency response curve of the overall test setup To explain this characteristic consider the

dynamic model shown in Figure 19 The following mechanical parameters are defined for

Figure 19(a) m k and b are the mass stiffness and equivalent viscous damping constant respectively

of the test package and me ke and be are the corresponding parameters of the exciter (shaker) Also in

the equivalent electrical circuit of the shaker head as shown in Figure 19(b) the following electrical

parameters are defined Re and Le are the resistance and (leakage) inductance and kb is the back

electromotive force (back emf) of the linear motor Assuming that the gravitational forces are supported

FIGURE 18 Schematic sectional view of a typical electromagnetic shaker manufactured by Bruel and Kjaer

Denmark

Vibration Monitoring Testing and Instrumentation1-12

53191mdash522007mdash1202mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

by the static deflections of the flexible elements and that the displacements are measured from the static

equilibrium position we have the following system equations

Test object meuroy frac14 2kethy2 yeTHORN2 beth_y2 _yeTHORN eth119THORNShaker head me euroye frac14 fe thorn kethy2 yeTHORN thorn beth_y2 _yeTHORN2 key 2 be _ye eth120THORN

Electrical Lediedt

thorn Reie thorn kb _ye frac14 vethtTHORN eth121THORN

The electromagnetic force fe generated in the shaker head is a result of the interaction of the magnetic

field generated by the current ie with coil of the moving shaker head and the constant magnetic field

(stator) in which the head coil is located Here we have

fe frac14 kbie eth122THORNNote that v(t) is the voltage signal that is applied by the amplifier to the shaker coil ye is the displacement

of the shaker head and y is the displacement response of the test package

It is assumed that kb has consistent electrical and mechanical units (Vmsec and NA) Usually

the electrical time constant of the shaker is quite small compared with the primarily mechanical

time constants of the shaker and the test package In such cases the Ledie=dt term in Equation 121 may

be neglected Consequently the equations from Equation 119 through Equation 122 may be

expressed in the Laplace (frequency) domain with the Laplace variable s taking the place of the derivative

d=dt as

ethms2 thorn bsthorn kTHORNy frac14 ethbsthorn kTHORNye eth123THORN

FIGURE 19 Dynamic models of an electromagnetic shaker and a flexible test package (a) mechanical model

(b) electrical model

Vibration Instrumentation 1-13

53191mdash522007mdash1202mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

frac12mes2 thorn ethbthorn beTHORNsthorn ethkthorn keTHORN ye frac14 ethbsthorn kTHORNy thorn kb

Rev2

k2bs

Reye eth124THORN

It follows that the transfer function of the shaker head motion with respect to the excitation voltage is

given by

yevfrac14 kb

Re

DethsTHORNDdethsTHORN eth125THORN

where DethsTHORN is the characteristic function of the primary dynamics of the test object

DethsTHORN frac14 ms2 thorn bsthorn k eth126THORN

and DdethsTHORN is the characteristic function of the primary dynamic interactions between the shaker and thetest object

DcethsTHORN frac14 mmes4 thorn frac12methbe thorn bthorn boTHORN thornmeb s

3 thorn frac12methke thorn kTHORN thornmekthorn bethbe thorn boTHORN s2thorn frac12bke thorn ethbe thorn boTHORNk sthorn kke

eth127THORN

where

bo frac14 k2bRe

eth128THORN

It is clear that under low damping conditions DdethsTHORN will produce two resonances as it is fourth order in sand similarly DethsTHORN will produce one antiresonance (trough) corresponding to the resonance of the testobject Note that in the frequency domain s frac14 jv and hence the frequency response function given by

Equation 125 is in fact

yevfrac14 kb

Rb

DethjvTHORNDdethjvTHORN eth129THORN

The magnitude of this frequency response function for a typical test system is sketched in Figure 110

Note that this curve is for the ldquoopen-looprdquo case where there is no feedback from the shaker controller

In practice the shaker controller will be able

to compensate for the resonances and anti-

resonances to some degree depending on its

effectiveness

The main advantages of electromagnetic

shakers are their high frequency range of

operation their high degree of operating flexi-

bility and the high level of accuracy of the

generated shaker motion Faithful reproduction

of complex excitations is possible because of the

advanced electronics and control systems used in

this type of shakers Electromagnetic shakers are

not suitable for heavy-duty applications (large test

objects) however High test-input accelerations

are possible at high frequencies when electromag-

netic shakers are used but their displacement and

velocity capabilities are limited to low or

intermediate values (see Table 11)

100

10

1 10 100Excitation Frequency (Hz)

Antiresonance

Resonance

Shak

erD

ispl

acem

entM

agni

tude

Resonance

1000

FIGURE 110 Frequency response curve of a typical

electromagnetic shaker with a test object

Vibration Monitoring Testing and Instrumentation1-14

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copy 2007 by Taylor amp Francis Group LLC

1221 Transient Exciters

Other varieties of exciters are commonly used in

transient-type vibration testing In these tests

either an impulsive force or an initial excitation is

applied to the test object and the resulting

response is monitored The excitations and the

responses are ldquotransientrdquo in this case Hammer

test drop tests and pluck tests fall into this

category For example a hammer test may be

conducted by hitting the object with an instru-

mented hammer and then measuring the response

of the object The hammer has a force sensor at its

tip as sketched in Figure 111 A piezoelectric or

strain-gage type force sensor may be used More

sophisticated hammers have impedance heads in

place of force sensors An impedance head

measures force and acceleration simultaneously

The results of a hammer test will depend on many

factors for example the dynamics of the hammer

body how firmly the hammer is held during the

impact how quickly the impact is applied and

whether there are multiple impacts

13 Control System

The two primary functions of the shaker control system in vibration testing are (1) to guarantee that the

specified excitation is applied to the test object and (2) to ensure that the dynamic stability (motion

constraints) of the test setup is preserved An operational block diagram illustrating these control

functions is given in Figure 112 The reference input to the control system represents the desired

excitation force that should be applied to the test object In the absence of any control however the force

reaching the test object will be distorted primarily because of (1) dynamic interactions and

nonlinearities of the shaker the test table the mounting fixtures the auxiliary instruments and the test

object itself (2) noise and errors in the signal generator amplifiers filters and other equipment and (3)

external loads and disturbances acting on the test object and other components (for example external

restraints aerodynamic forces friction) To compensate for these distorting factors response

measurements (displacements velocities acceleration and so on) are made at various locations in the

test setup and are used to control the system dynamics In particular the responses of the shaker the test

table and the test object are measured These responses are used to compare the actual excitation felt by

FIGURE 111 An instrumented hammer used in bump

tests or hammer tests

ExcitationInput

(Reference)

Feedback Paths

DriveSignal

ShakerResponse

TestTable

TestObject

Test ObjectResponse

Test TableResponseExciter

(Shaker)(Ram)

Controllerand

Amplifier

FIGURE 112 Operational block diagram illustrating a general shaker control system

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the test object at the shaker interface with the desired (specified) input The drive signal to the shaker is

modified depending on the error that is present

Two types of control are commonly employed in shaker apparatus simple manual control and

complex automatic control Manual control normally consists of simple open-loop trial-and-error

methods of manual adjustments (or calibration) of the control equipment to obtain a desired dynamic

response The actual response is usually monitored (on an oscilloscope or frequency analyzer screen for

example) during manual-control operations The pretest adjustments in manual control can be very

time-consuming as a result the test object might be subjected to overtesting which could produce

cumulative damage is undesirable and could defeat the test purpose Furthermore the calibration

procedure for the experimental setup must be repeated for each new test object

The disadvantages ofmanual control suggest that automatic control is desirable in complex test schemes

in which high accuracy of testing is desired The first step of automatic control involves automatic

measurement of the system response using control sensors and transducers The measurement is then fed

back into the control system which instantaneously determines the best drive signal to actuate the shaker

in order to get the desired excitation This may be done by either analog or digital methods

Primitive control systems require an accurate mathematical description of the test object This

dependency of the control system on the knowledge of test-object dynamics is clearly undesirable

Performance of a good control system should not be considerably affected by the dynamic interactions

and nonlinearities of the test object or by the nature of the excitation Proper selection of feedback signals

and control-system components can reduce such effects and will make the system robust

In the response-spectrum method of vibration testing it is customary to use displacement control at

low frequencies velocity control at intermediate frequency and acceleration control at high frequencies

This necessitates feedback of displacement velocity and acceleration responses Generally however the

most important feedback is the velocity feedback In sine-sweep tests the shaker velocity must change

steadily over the frequency band of interest In particular the velocity control must be precise near the

resonances of the test object Velocity (speed) feedback has a stabilizing effect on the dynamics which is

desirable This effect is particularly useful in ensuring stability in motion when testing is done near

resonances of lightly damped test objects On the contrary displacement (position) feedback can have a

destabilizing effect on some systems particularly when high feedback gains are used

The controller usually consists of various instruments equipment and computation hardware and

software Often the functions of the data-acquisition and processing system overlap with those of the

controller to some extent As an example consider the digital-controller of vibration testing apparatus

First the responses are measured through sensors (and transducers) filtered and amplified

(conditioned) These data channels may be passed through a multiplexer whose purpose is to select

one data channel at a time for processing Most modern data acquisition hardware does not need a

separate multiplexer to handle multiple signals The analog data are converted into digital data using

analog-to-digital converters (ADCs) The resulting sampled data are stored on a disk or as a block data in

the computer memory The reference input signal (typically a signal recorded on an FM tape) is also

sampled (if it is not already in the digital form) using an ADC and fed into the computer Digital

processing is done on the reference signal and the response data with the objective of computing the

command signal to drive the shaker The digital command signal is converted into an analog signal using

a digital-to-analog converter (DAC) and amplified (conditioned) before it is used to drive the exciter

The nature of the control components depends to a large extent on the nature and objectives of the

particular test to be conducted Some of the basic components in a shaker controller are described in

the following subsections

131 Components of a Shaker Controller

1311 Compressor

A compressor circuit is incorporated in automatic excitation control devices to control the excitation-

input level automatically The level of control depends on the feedback signal from a control sensor and

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the specified (reference) excitation signal Usually the compressor circuit is included in the excitation-

signal generator (for example in a sine generator) The control by this means may be done on the basis of

a single-frequency component (eg the fundamental frequency)

1312 Equalizer (Spectrum Shaper)

Random-signal equalizers are used to shape the spectrum of a random signal in a desired manner In

essence and equalizer consists of a bank of narrow-band filters (for example 80 filters) in parallel over

the operating frequency range By passing the signal through each filter the spectral density (or the mean

square value) of the signal in that narrow frequency band (for example each one-third-octave band) is

determined This is compared with the desired spectral level and automatic adjustment is made in that

filter in case there is an error In some systems response-spectrum analysis is made in place of power

spectral density analysis In that case the equalizer consists of a bank of simple oscillators whose

resonant frequencies are distributed over the operating frequency range of the equalizer The feedback

signal is passed through each oscillator and the peak value of its output is determined This value is

compared with the desired response spectrum value at that frequency If there is an error automatic gain

adjustment is made in the appropriate excitation signal components

Random-noise equalizers are used in conjunction with random signal generators They receive

feedback signals from the control sensors In some digital control systems there are algorithms (software)

that are used to iteratively converge the spectrum of the excitation signal felt by the test object into the

desired spectrum

1313 Tracking Filter

Many vibration tests are based on single-frequency excitations In such cases the control functions

should be performed on the basis of the amplitudes of the fundamental-frequency component of the

signal A tracking filter is simply a frequency-tuned band-pass filter It automatically tunes the center

frequency of its very narrow-band-pass filter to the frequency of a carrier signal Then when a noisy

signal is passed through the tuned filter the output of the filter will be the required fundamental

frequency component in the signal Tracking filters also are useful in obtaining amplitudendashfrequency

plots using an XndashY plotter In such cases the frequency value comes from the signal generator (sweep

oscillator) which produces the carrier signal to the tracking filter The tracking filter then determines the

corresponding amplitude of a signal that is fed into it Most tracking filters have dual channels so that two

signals can be handled (tracked) simultaneously

1314 Excitation Controller (Amplitude Servo-Monitor)

An excitation controller is typically an integral part of the signal generator It can be set so that automatic

sweep between two frequency limits can be performed at a selected sweep rate (linear or logarithmic)

More advanced excitation controllers have the capability of an automatic switch-over between constant-

displacement constant-velocity and constant-acceleration excitation-input control at specified

frequencies over the sweep frequency interval Consequently integrator circuits should be present

within the excitation controller unit to determine velocities and displacements from acceleration signals

Sometimes integration is performed by a separate unit called a vibration meter This unit also offers

the operator the capability of selecting the desired level of each signal (acceleration velocity or

displacement) There is an automatic cut-off level for large displacement values that could result from

noise in acceleration signals A compressor is also a subcomponent of the excitation controller The

complete unit is sometimes known as an amplitude servo-monitor

132 Signal-Generating Equipment

Shakers are force-generating devices that are operated using drive (excitation) signals generated from a

source The excitation-signal source is known as the signal generator Three major types of signal

generators are used in vibration testing applications (1) oscillators (2) random-signal generators and

(3) storage devices In some units oscillators and random-signal generators are combined We shall

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discuss these two generators separately however because of their difference in function It also should be

noted that almost any digital signal (deterministic or random) can be generated by a digital computer

using a suitable computer program the signal eventually can be passed through a DAC to obtain

the corresponding analog signal These lsquodigitalrsquo signal generators along with analog sources such as

magnetic tape players (FM) are classified into the category of storage devices

The dynamic range of equipment is the ratio of the maximum and minimum output levels (expressed

in decibels) at which it is capable of operating without significant error This is an important specification

for many types of equipment particularly for signal-generating devices The output level of the signal

generator should be set to a value within its dynamic range

1321 Oscillators

Oscillators are essentially single-frequency generators Typically sine signals are generated but other

waveforms (such as rectangular and triangular pulses) are also available in most oscillators Normally

an oscillator has two modes of operation (1) sweeping up and down between two frequency limits and

(2) dwelling at a specified frequency In the sweep operation the sweep rate should be specified This can

be done either on a linear scale (Hzmin) or on a logarithmic scale (octavesmin) In the dwell operation

the frequency points (or intervals) should be specified In either case a desired signal level can be chosen

using the gain-control knob An oscillator that is operated exclusively in the sweep mode is called a sweep

oscillator

The early generation of oscillators employed variable inductor-capacitor types of electronic circuits to

generate signals oscillating at a desired frequency The oscillator is tuned to the required frequency by

varying the capacitance or inductance parameters A DC voltage is applied to energize the capacitor

and to obtain the desired oscillating voltage signal which subsequently is amplified and conditioned

Modern oscillators use operational amplifier circuits along with resistor capacitor and semiconductor

(SC) elements Also common are crystal (quartz) parallel-resonance oscillators used to generate voltage

signals accurately at a fixed frequency The circuit is activated using a DC-voltage source Other

frequencies of interest are obtained by passing this high-frequency signal through a frequency converter

The signal is then conditioned (amplified and filtered) Required shaping (for example rectangular

pulse) is obtained using a shape circuit Finally the required signal level is obtained by passing the

resulting signal through a variable-gain amplifier A block diagram of an oscillator illustrating various

stages in the generation of a periodic signal is given in Figure 113

A typical oscillator offers a choice of several (typically six) linear and logarithmic frequency ranges and

a sizable level of control capability (for example 80 dB) Upper and lower frequency limits in a sweep can

be preset on the front panel to any of the available frequency ranges Sweep-rate settings are continuously

DC Voltage

Oscillator

FrequencySpecification

FrequencyConverter

FilterAmplifier

ShaperPeriodicSignal

FrequencyCounter

Fixed-FrequencySignal

Variable-GainOutput

Amplifier

SignalSpecification

LevelSpecification

FIGURE 113 Block diagram of an oscillator-type signal generator

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  • 53191fm
    • Vibration Monitoring Testing and Instrumentation
      • Preface
      • Acknowledgments
      • Editor-in-Chief
      • Contributors
      • Contents
      • Related Titles
          • 53191ch1
            • Table of Contents
            • Chapter 1 Vibration Instrumentation
              • Summary
              • 11 Introduction
              • 12 Vibration Exciters
                • 121 Shaker Selection
                  • 1211 Force Rating
                  • 1212 Power Rating
                  • 1213 Stroke Rating
                  • 1214 Hydraulic Shakers
                  • 1215 Inertial Shakers
                  • 1216 Electromagnetic Shakers
                    • 122 Dynamics of Electromagnetic Shakers
                      • 1221 Transient Exciters
                          • 13 Control System
                            • 131 Components of a Shaker Controller
                              • 1311 Compressor
                              • 1312 Equalizer (Spectrum Shaper)
                              • 1313 Tracking Filter
                              • 1314 Excitation Controller (Amplitude Servo-Monitor)
                                • 132 Signal-Generating Equipment
                                  • 1321 Oscillators
                                  • 1322 Random Signal Generators
                                  • 1323 Tape Players
                                  • 1324 Data Processing
                                      • 14 Performance Specification
                                        • 141 Parameters for Performance Specification
                                          • 1411 Time-Domain Specifications
                                          • 1412 Frequency-Domain Specifications
                                            • 142 Linearity
                                            • 143 Instrument Ratings
                                              • 1431 Rating Parameters
                                                • 144 Accuracy and Precision
                                                  • 15 Motion Sensors and Transducers
                                                    • 151 Potentiometer
                                                      • 1511 Potentiometer Resolution
                                                      • 1512 Optical Potentiometer
                                                        • 152 Variable-Inductance Transducers
                                                          • 1521 Mutual-Induction Transducers
                                                          • 1522 Linear-Variable Differential Transformer
                                                          • 1523 Signal Conditioning
                                                            • 153 Mutual-Induction Proximity Sensor
                                                            • 154 Selfinduction Transducers
                                                            • 155 Permanent-Magnet Transducers
                                                            • 156 Alternating Current Permanent-Magnet Tachometer
                                                            • 157 Alternating Current Induction Tachometer
                                                            • 158 Eddy Current Transducers
                                                            • 159 Variable-Capacitance Transducers
                                                              • 1591 Capacitive Displacement Sensors
                                                              • 1592 Capacitive Angular Velocity Sensor
                                                              • 1593 Capacitance Bridge Circuit
                                                                • 1510 Piezoelectric Transducers
                                                                  • 15101 Sensitivity
                                                                  • 15102 Piezoelectric Accelerometer
                                                                  • 15103 Charge Amplifier
                                                                      • 16 Torque Force and Other Sensors
                                                                        • 161 Strain Gage Sensors
                                                                          • 1611 Equations for Strain Gage Measurements
                                                                          • 1612 Bridge Sensitivity
                                                                          • 1613 The Bridge Constant
                                                                          • 1614 The Calibration Constant
                                                                          • 1615 Data Acquisition
                                                                          • 1616 Accuracy Considerations
                                                                          • 1617 Semiconductor Strain Gages
                                                                          • 1618 Force and Torque Sensors
                                                                          • 1619 Strain Gage Torque Sensors
                                                                          • 16110 Deflection Torque Sensors
                                                                          • 16111 Variable-Reluctance Torque Sensor
                                                                          • 16112 Reaction Torque Sensors
                                                                            • 162 Miscellaneous Sensors
                                                                              • 1621 Stroboscope
                                                                              • 1622 Fiber Optic Sensors and Lasers
                                                                              • 1623 Fiber-Optic Gyroscope
                                                                              • 1624 Laser Doppler Interferometer
                                                                              • 1625 Ultrasonic Sensors
                                                                              • 1626 Gyroscopic Sensors
                                                                                  • References
                                                                                  • Appendix 1A Virtual Instrumentation for Data Acquisition Analysis and Presentation
                                                                                    • Summary
                                                                                    • List of Abbreviations
                                                                                    • 1A1 Dynamic Signals
                                                                                      • 1A11 Acquiring and Simulating Dynamic Signals
                                                                                        • 1A111 Aliasing
                                                                                        • 1A112 Time Continuity
                                                                                            • 1A2 Measurement Configuration Considerations
                                                                                              • 1A21 Input Signal Considerations
                                                                                                • 1A211 Input Pseudodifferential and Differential Configuration
                                                                                                • 1A212 Gain
                                                                                                • 1A213 Input Coupling
                                                                                                • 1A214 Integrated Electronic Piezoelectric Excitation
                                                                                                • 1A215 Nyquist Frequency and Bandwidth
                                                                                                • 1A216 Analog-to-Digital Conversion
                                                                                                • 1A217 Antialias Filters
                                                                                                • 1A218 Input Filter Delay
                                                                                                • 1A219 Overload Detection
                                                                                                  • 1A22 Output Signal Considerations
                                                                                                    • 1A221 Output Pseudodifferential and Differential Configuration
                                                                                                    • 1A222 Attenuation
                                                                                                    • 1A223 Digital-to-Analog Conversion
                                                                                                    • 1A224 Anti-imaging and Interpolation Filters
                                                                                                    • 1A225 Output Filter Delay
                                                                                                        • 1A3 Scaling and Calibration
                                                                                                          • 1A31 Scaling to Engineering Units
                                                                                                          • 1A32 Performing System Calibration
                                                                                                            • 1A321 Propagation Delay Calibration
                                                                                                                • 1A4 Limit Testing Analysis
                                                                                                                  • 1A41 Limit Testing Overview
                                                                                                                  • 1A42 Using the SVT Limit Testing VI
                                                                                                                    • 1A5 Integration
                                                                                                                      • 1A51 Introduction to Integration
                                                                                                                      • 1A52 Implementing Integration
                                                                                                                        • 1A521 Challenges when Integrating Vibration Data
                                                                                                                          • 1A53 Time-Domain Integration
                                                                                                                            • 1A531 Single-Shot Acquisition and Integration
                                                                                                                            • 1A532 Continuous Acquisition and Integration
                                                                                                                              • 1A54 Frequency-Domain Integration
                                                                                                                                • 1A6 Vibration-Level Measurements
                                                                                                                                  • 1A61 Measuring the Root Mean Square Level
                                                                                                                                    • 1A611 Single-Shot Buffered Acquisition
                                                                                                                                    • 1A612 Continuous Signal Acquisition
                                                                                                                                      • 1A62 Performing a Running RMS Level Measurement
                                                                                                                                      • 1A63 Computing the Peak Level
                                                                                                                                      • 1A64 Computing the Crest Factor
                                                                                                                                        • 1A7 Frequency Analysis
                                                                                                                                          • 1A71 FFT Fundamentals
                                                                                                                                            • 1A711 Number of Samples
                                                                                                                                            • 1A712 Frequency Resolution
                                                                                                                                            • 1A713 Maximum Resolvable Frequency
                                                                                                                                            • 1A714 Minimum Resolvable Frequency
                                                                                                                                            • 1A715 Number of Spectral Lines
                                                                                                                                            • 1A716 Relationship between Time-Domain and Frequency-Domain Specifications and Parameters
                                                                                                                                              • 1A72 Increasing Frequency Resolution
                                                                                                                                                • 1A721 Zoom FFT Analysis
                                                                                                                                                • 1A722 Frequency Resolution of the Zoom FFT VIs
                                                                                                                                                • 1A723 Zoom Measurement
                                                                                                                                                • 1A724 Zoom Settings
                                                                                                                                                • 1A725 Subset Analysis
                                                                                                                                                    • 1A8 Transient Analysis
                                                                                                                                                      • 1A81 Transient Analysis with the Sound and Vibration Toolkit
                                                                                                                                                      • 1A82 Performing an STFT vs Time
                                                                                                                                                        • 1A821 Selecting the FFT Block Size
                                                                                                                                                        • 1A822 Overlapping
                                                                                                                                                        • 1A823 Using the SVT STFT vs Time VI
                                                                                                                                                          • 1A83 Performing an STFT vs Rotational Speed
                                                                                                                                                            • 1A831 Converting the Pulse Train to Rotational Speed
                                                                                                                                                            • 1A832 STFT vs RPM
                                                                                                                                                              • 1A84 Measuring a Shock Response Spectrum
                                                                                                                                                                • 1A9 Waterfall Display
                                                                                                                                                                  • 1A91 Using the Display VIs
                                                                                                                                                                    • 1A911 Initializing the Display
                                                                                                                                                                    • 1A912 Sending Data to the Display
                                                                                                                                                                    • 1A913 Waterfall Display for Frequency Analysis
                                                                                                                                                                    • 1A914 Waterfall Display for Transient Analysis
                                                                                                                                                                    • 1A915 Waterfall Display for Octave Spectra
                                                                                                                                                                        • 1A10 Swept-Sine Measurements
                                                                                                                                                                          • 1A101 Swept-Sine Overview
                                                                                                                                                                          • 1A102 Choosing Swept-Sine vs FFT Measurements
                                                                                                                                                                          • 1A103 Taking a Swept-Sine Measurement
                                                                                                                                                                          • 1A104 Swept-Sine Measurement Example
                                                                                                                                                                              • Bibliography
                                                                                                                                                                              • Related Titles
                                                                                                                                                                                  • 53191ch2
                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                    • Chapter 2 Signal Conditioning and Modification
                                                                                                                                                                                      • Summary
                                                                                                                                                                                      • 21 Introduction
                                                                                                                                                                                      • 22 Amplifiers
                                                                                                                                                                                        • 221 Operational Amplifier
                                                                                                                                                                                        • 222 Use of Feedback in Opamp
                                                                                                                                                                                        • 223 Voltage Current and Power Amplifiers
                                                                                                                                                                                          • 2231 Charge Amplifiers
                                                                                                                                                                                            • 224 Instrumentation Amplifiers
                                                                                                                                                                                              • 2241 Differential Amplifier
                                                                                                                                                                                              • 2242 Common Mode
                                                                                                                                                                                                • 225 Amplifier Performance Ratings
                                                                                                                                                                                                  • 2251 Common-Mode Rejection Ratio
                                                                                                                                                                                                    • 226 Component Interconnection
                                                                                                                                                                                                      • 2261 Impedance Characteristics
                                                                                                                                                                                                      • 2262 Cascade Connection of Devices
                                                                                                                                                                                                      • 2263 AC-Coupled Ampliers
                                                                                                                                                                                                          • 23 Analog Filters
                                                                                                                                                                                                            • 231 Passive Filters and Active Filters
                                                                                                                                                                                                              • 2311 Number of Poles
                                                                                                                                                                                                                • 232 Low-Pass Filters
                                                                                                                                                                                                                  • 2321 Low-Pass Butterworth Filter
                                                                                                                                                                                                                    • 233 High-Pass Filters
                                                                                                                                                                                                                    • 234 Band-Pass Filters
                                                                                                                                                                                                                      • 2341 Resonance-Type Band-Pass Filters
                                                                                                                                                                                                                        • 235 Band-Reject Filters
                                                                                                                                                                                                                          • 24 Modulators and Demodulators
                                                                                                                                                                                                                            • 241 Amplitude Modulation
                                                                                                                                                                                                                              • 2411 Modulation Theorem
                                                                                                                                                                                                                              • 2412 Side Frequencies and Side Bands
                                                                                                                                                                                                                                • 242 Application of Amplitude Modulation
                                                                                                                                                                                                                                  • 2421 Fault Detection and Diagnosis
                                                                                                                                                                                                                                    • 243 Demodulation
                                                                                                                                                                                                                                      • 25 Analog ndashDigital Conversion
                                                                                                                                                                                                                                        • 251 Digital-to-Analog Conversion
                                                                                                                                                                                                                                          • 2511 DAC Error Sources
                                                                                                                                                                                                                                            • 252 Analog-to-Digital Conversion
                                                                                                                                                                                                                                            • 253 Analog-to-Digital Converter Performance Characteristics
                                                                                                                                                                                                                                              • 2531 Resolution and Quantization Error
                                                                                                                                                                                                                                              • 2532 Monotonicity Nonlinearity and Offset Error
                                                                                                                                                                                                                                              • 2533 Analog-to-Digital Converter Conversion Rate
                                                                                                                                                                                                                                                • 254 Sample-and-Hold Circuitry
                                                                                                                                                                                                                                                • 255 Digital Filters
                                                                                                                                                                                                                                                  • 2551 Software Implementation and Hardware Implementation
                                                                                                                                                                                                                                                      • 26 Bridge Circuits
                                                                                                                                                                                                                                                        • 261 Wheatstone Bridge
                                                                                                                                                                                                                                                        • 262 Constant-Current Bridge
                                                                                                                                                                                                                                                        • 263 Bridge Amplifiers
                                                                                                                                                                                                                                                          • 2631 Half-Bridge Circuits
                                                                                                                                                                                                                                                            • 264 Impedance Bridges
                                                                                                                                                                                                                                                              • 2641 Owen Bridge
                                                                                                                                                                                                                                                              • 2642 Wien-Bridge Oscillator
                                                                                                                                                                                                                                                                  • 27 Linearizing Devices
                                                                                                                                                                                                                                                                    • 271 Linearization by Software
                                                                                                                                                                                                                                                                    • 272 Linearization by Hardware Logic
                                                                                                                                                                                                                                                                    • 273 Analog Linearizing Circuitry
                                                                                                                                                                                                                                                                    • 274 Offsetting Circuitry
                                                                                                                                                                                                                                                                    • 275 Proportional-Output Circuitry
                                                                                                                                                                                                                                                                      • 2751 Curve-Shaping Circuitry
                                                                                                                                                                                                                                                                          • 28 Miscellaneous Signal Modification Circuitry
                                                                                                                                                                                                                                                                            • 281 Phase Shifters
                                                                                                                                                                                                                                                                            • 282 Voltage-to-Frequency Converter
                                                                                                                                                                                                                                                                            • 283 Frequency-to-Voltage Converter
                                                                                                                                                                                                                                                                            • 284 Voltage-to-Current Converters
                                                                                                                                                                                                                                                                            • 285 Peak-Hold Circuits
                                                                                                                                                                                                                                                                              • 29 Signal Analyzers and Display Devices
                                                                                                                                                                                                                                                                                • 291 Signal Analyzers
                                                                                                                                                                                                                                                                                • 292 Oscilloscopes
                                                                                                                                                                                                                                                                                  • 2921 Triggering
                                                                                                                                                                                                                                                                                  • 2922 Lissajous Patterns
                                                                                                                                                                                                                                                                                  • 2923 Digital Oscilloscopes
                                                                                                                                                                                                                                                                                      • Bibliography
                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                          • 53191ch3
                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                            • Chapter 3 Vibration Testing
                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                              • 31 Introduction
                                                                                                                                                                                                                                                                                              • 32 Representation of a Vibration Environment
                                                                                                                                                                                                                                                                                                • 321 Test Signals
                                                                                                                                                                                                                                                                                                  • 3211 Stochastic vs Deterministic Signals
                                                                                                                                                                                                                                                                                                    • 322 Deterministic Signal Representation
                                                                                                                                                                                                                                                                                                      • 3221 Single-Frequency Signals
                                                                                                                                                                                                                                                                                                      • 3222 Sine Sweep
                                                                                                                                                                                                                                                                                                      • 3223 Sine Dwell
                                                                                                                                                                                                                                                                                                      • 3224 Decaying Sine
                                                                                                                                                                                                                                                                                                      • 3225 Sine Beat
                                                                                                                                                                                                                                                                                                      • 3226 Sine Beat with Pauses
                                                                                                                                                                                                                                                                                                      • 3227 Multifrequency Signals
                                                                                                                                                                                                                                                                                                      • 3228 Actual Excitation Records
                                                                                                                                                                                                                                                                                                      • 3229 Simulated Excitation Signals
                                                                                                                                                                                                                                                                                                        • 323 Stochastic Signal Representation
                                                                                                                                                                                                                                                                                                          • 3231 Ergodic Random Signals
                                                                                                                                                                                                                                                                                                          • 3232 Stationary Random Signals
                                                                                                                                                                                                                                                                                                          • 3233 Independent and Uncorrelated Signals
                                                                                                                                                                                                                                                                                                          • 3234 Transmission of Random Excitations
                                                                                                                                                                                                                                                                                                            • 324 Frequency-Domain Representations
                                                                                                                                                                                                                                                                                                              • 3241 Fourier Spectrum Method
                                                                                                                                                                                                                                                                                                              • 3242 Power Spectral Density Method
                                                                                                                                                                                                                                                                                                                • 325 Response Spectrum
                                                                                                                                                                                                                                                                                                                  • 3251 Displacement Velocity and Acceleration Spectra
                                                                                                                                                                                                                                                                                                                  • 3252 Response-Spectra Plotting Paper
                                                                                                                                                                                                                                                                                                                  • 3253 Zero-Period Acceleration
                                                                                                                                                                                                                                                                                                                  • 3254 Uses of Response Spectra
                                                                                                                                                                                                                                                                                                                    • 326 Comparison of Various Representations
                                                                                                                                                                                                                                                                                                                      • 33 Pretest Procedures
                                                                                                                                                                                                                                                                                                                        • 331 Purpose of Testing
                                                                                                                                                                                                                                                                                                                        • 332 Service Functions
                                                                                                                                                                                                                                                                                                                          • 3321 Active Equipment
                                                                                                                                                                                                                                                                                                                          • 3322 Passive Equipment
                                                                                                                                                                                                                                                                                                                          • 3323 Functional Testing
                                                                                                                                                                                                                                                                                                                            • 333 Information Acquisition
                                                                                                                                                                                                                                                                                                                              • 3331 Interface Details
                                                                                                                                                                                                                                                                                                                              • 3332 Effect of Neglecting Interface Dynamics
                                                                                                                                                                                                                                                                                                                              • 3333 Effects of Damping
                                                                                                                                                                                                                                                                                                                              • 3334 Effects of Inertia
                                                                                                                                                                                                                                                                                                                              • 3335 Effect of Natural Frequency
                                                                                                                                                                                                                                                                                                                              • 3336 Effect of Excitation Frequency
                                                                                                                                                                                                                                                                                                                              • 3337 Other Effects of Interface
                                                                                                                                                                                                                                                                                                                                • 334 Test-Program Planning
                                                                                                                                                                                                                                                                                                                                  • 3341 Testing of Cabinet-Mounted Equipment
                                                                                                                                                                                                                                                                                                                                    • 335 Pretest Inspection
                                                                                                                                                                                                                                                                                                                                      • 34 Testing Procedures
                                                                                                                                                                                                                                                                                                                                        • 341 Resonance Search
                                                                                                                                                                                                                                                                                                                                        • 342 Methods of Determining Frequency-Response Functions
                                                                                                                                                                                                                                                                                                                                          • 3421 Fourier Transform Method
                                                                                                                                                                                                                                                                                                                                          • 3422 Spectral Density Method
                                                                                                                                                                                                                                                                                                                                          • 3423 Harmonic Excitation Method
                                                                                                                                                                                                                                                                                                                                            • 343 Resonance-Search Test Methods
                                                                                                                                                                                                                                                                                                                                              • 3431 Hammer (Bump) Test and Drop Test
                                                                                                                                                                                                                                                                                                                                              • 3432 Pluck Test
                                                                                                                                                                                                                                                                                                                                              • 3433 Shaker Tests
                                                                                                                                                                                                                                                                                                                                                • 344 Mechanical Aging
                                                                                                                                                                                                                                                                                                                                                  • 3441 Equivalence for Mechanical Aging
                                                                                                                                                                                                                                                                                                                                                  • 3442 Excitation-Intensity Equivalence
                                                                                                                                                                                                                                                                                                                                                  • 3443 Dynamic-Excitation Equivalence
                                                                                                                                                                                                                                                                                                                                                  • 3444 Cumulative Damage Theory
                                                                                                                                                                                                                                                                                                                                                    • 345 Test-Response Spectrum Generation
                                                                                                                                                                                                                                                                                                                                                    • 346 Instrument Calibration
                                                                                                                                                                                                                                                                                                                                                    • 347 Test-Object Mounting
                                                                                                                                                                                                                                                                                                                                                    • 348 Test-Input Considerations
                                                                                                                                                                                                                                                                                                                                                      • 3481 Test Nomenclature
                                                                                                                                                                                                                                                                                                                                                      • 3482 Testing with Uncorrelated Excitations
                                                                                                                                                                                                                                                                                                                                                      • 3483 Symmetrical Rectilinear Testing
                                                                                                                                                                                                                                                                                                                                                      • 3484 Geometry vs Dynamics
                                                                                                                                                                                                                                                                                                                                                      • 3485 Some Limitations
                                                                                                                                                                                                                                                                                                                                                      • 3486 Testing Black Boxes
                                                                                                                                                                                                                                                                                                                                                      • 3487 Phasing of Excitations
                                                                                                                                                                                                                                                                                                                                                      • 3488 Testing a Gray or White Box
                                                                                                                                                                                                                                                                                                                                                      • 3489 Overtesting in Multitest Sequences
                                                                                                                                                                                                                                                                                                                                                          • 35 Some Practical Information
                                                                                                                                                                                                                                                                                                                                                            • 351 Random Vibration Test Example
                                                                                                                                                                                                                                                                                                                                                            • 352 Vibration Shakers and Control Systems
                                                                                                                                                                                                                                                                                                                                                              • Bibliography
                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                  • 53191ch4
                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                    • Chapter 4 Experimental Modal Analysis
                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                      • 41 Introduction
                                                                                                                                                                                                                                                                                                                                                                      • 42 Frequency-Domain Formulation
                                                                                                                                                                                                                                                                                                                                                                        • 421 Transfer-Function Matrix
                                                                                                                                                                                                                                                                                                                                                                        • 422 Principle of Reciprocity
                                                                                                                                                                                                                                                                                                                                                                          • 43 Experimental Model Development
                                                                                                                                                                                                                                                                                                                                                                            • 431 Extraction of the Time-Domain Model
                                                                                                                                                                                                                                                                                                                                                                              • 44 Curve Fitting of Transfer Functions
                                                                                                                                                                                                                                                                                                                                                                                • 441 Problem Identification
                                                                                                                                                                                                                                                                                                                                                                                • 442 Single- and Multi-Degree-of-Freedom Techniques
                                                                                                                                                                                                                                                                                                                                                                                • 443 Single-Degree-of-Freedom Parameter Extraction in the Frequency Domain
                                                                                                                                                                                                                                                                                                                                                                                  • 4431 Circle-Fit Method
                                                                                                                                                                                                                                                                                                                                                                                    • Case of Viscous Damping
                                                                                                                                                                                                                                                                                                                                                                                    • Case of Hysteretic Damping
                                                                                                                                                                                                                                                                                                                                                                                      • 4432 Peak-Picking Method
                                                                                                                                                                                                                                                                                                                                                                                        • 444 Multi-Degree of Freedom Curve Fitting
                                                                                                                                                                                                                                                                                                                                                                                          • 4441 Formulation of the Method
                                                                                                                                                                                                                                                                                                                                                                                            • 445 A Comment on Static Modes and Rigid-Body Modes
                                                                                                                                                                                                                                                                                                                                                                                            • 446 Residue Extraction
                                                                                                                                                                                                                                                                                                                                                                                              • 45 Laboratory Experiments
                                                                                                                                                                                                                                                                                                                                                                                                • 451 Lumped-Parameter System
                                                                                                                                                                                                                                                                                                                                                                                                  • 4511 Frequency-Domain Test
                                                                                                                                                                                                                                                                                                                                                                                                  • 4512 Time-Domain Tests
                                                                                                                                                                                                                                                                                                                                                                                                    • 452 Distributed-Parameter System
                                                                                                                                                                                                                                                                                                                                                                                                      • 46 Commercial EMA Systems
                                                                                                                                                                                                                                                                                                                                                                                                        • 461 System Configuration
                                                                                                                                                                                                                                                                                                                                                                                                          • 4611 FFT Analysis Options
                                                                                                                                                                                                                                                                                                                                                                                                          • 4612 Modal Analysis Components
                                                                                                                                                                                                                                                                                                                                                                                                              • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                  • 53191ch5
                                                                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                    • Chapter 5 Mechanical Shock
                                                                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                      • 51 Definitions
                                                                                                                                                                                                                                                                                                                                                                                                                        • 511 Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 512 Simple (or Perfect) Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 513 Half-Sine Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 514 Versed-Sine (or Haversine) Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 515 Terminal Peak Sawtooth Shock or Final Peak Sawtooth Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 516 Rectangular Shock
                                                                                                                                                                                                                                                                                                                                                                                                                          • 5161 Trapezoidal Shock
                                                                                                                                                                                                                                                                                                                                                                                                                              • 52 Description in the Time Domain
                                                                                                                                                                                                                                                                                                                                                                                                                              • 53 Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                • 531 Need
                                                                                                                                                                                                                                                                                                                                                                                                                                • 532 Shock Response Spectrum Definition
                                                                                                                                                                                                                                                                                                                                                                                                                                • 533 Response of a Linear One-Degree-of-Freedom System
                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5331 Shock Defined by a Force
                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5332 Shock Defined by an Acceleration
                                                                                                                                                                                                                                                                                                                                                                                                                                    • 534 Definitions
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5341 Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5342 Absolute Acceleration Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5343 Relative Displacement Shock Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5344 Primary Positive Shock Response Spectrum or Initial Positive Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5345 Primary (or Initial) Negative Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5346 Secondary (or Residual) Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5347 Positive (or Maximum Positive) Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5348 Negative (or Maximum Negative) Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5349 Maximax Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53410 Choice of Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                        • 535 Standardized Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5351 Definition
                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5352 Standardized Shock Response Spectra of Simple Shocks
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53521 Half-Sine Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53522 Versed Sine Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53523 Terminal Peak Sawtooth Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53524 Rectangular Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53525 Trapezoidal Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 536 Choice of Damping
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 537 Shock Response Spectra Domains
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 538 Algorithms for Calculation of the Shock Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 539 Choice of the Digitization Frequency of the Signal
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5310 Use of Shock Response Spectra for the Study of Systems with Several Degrees of Freedom
                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 54 Pyroshocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 55 Use of Shock Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 551 Severity Comparison of Several Shocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 552 Test Specification Development from Real Environment Data
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5521 Synthesis of Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5522 Nature of the Specification
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5523 Choice of Shape
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5524 Amplitude
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5525 Duration
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5526 Difficulties
                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 56 Standards
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 561 Types of Standards
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 562 Installation Conditions of Test Item
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 563 Uncertainty Factor
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 564 Bump Test
                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 57 Damage Boundary Curve
                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 571 Definition
                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 572 Analysis of Test Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 58 Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 581 Main Types
                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 582 Impact Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5821 Universal Shock-Test Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 58211 Impact Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 58212 Impulse Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 583 Shock Simulators (Programmers)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5831 Half-Sine Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58311 Shock Duration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58312 Impact Velocity
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58313 Maximum Deformation of the Shock Simulator (Programmer)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58314 Shock Amplitude
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58315 Characteristics of the Target
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5832 Terminal Peak Sawtooth Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5833 Rectangular Pulse ndash Trapezoidal Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5834 Universal Shock Simulator (Programmer)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 58341 Generating a Half-Sine Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 58342 Generating a Terminal Peak Sawtooth Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 58343 Trapezoidal Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 584 Limitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5841 Limitations of the Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5842 Limitations of Shock Simulators
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 585 Pneumatic Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 586 High Impact Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5861 Lightweight High Impact Shock Machine
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5862 Medium Weight High Impact Shock Machine
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 587 Specific Test Facilities
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 59 Generation of Shock Using Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 591 Principle Behind the Generation of a Simple Shape Signal versus Time
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 592 Main Advantages
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 593 Pre- and Postshocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5931 Requirements
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5932 Solutions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 59321 Optimized Pre- and Postpulses
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5933 Incidence on the Shock Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 594 Limitations of Electrodynamic Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5941 Mechanical Limitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 59411 Abacuses
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5942 Electronic Limitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 595 The Use of Electrohydraulic Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 510 Control by a Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 5101 Principle
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 5102 Principal Shapes of Elementary Signals
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 51021 Decaying Sinusoid
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 51022 ZERD Function
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 51023 WAVSIN Waveform
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 5103 Comparison of WAVSIN SHOC Waveforms and Decaying Sinusoid
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 5104 Criticism of Control by a Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 511 Pyrotechnic Shock Simulation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5111 Simulation Using Pyrotechnic Facilities
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5112 Simulation Using Metal-to-Metal Impact
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5113 Simulation Using Electrodynamic Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5114 Simulation Using Conventional Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53191ch6
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Chapter 6 Machine Condition Monitoring and Fault Diagnostics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 61 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 62 Machinery Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 621 Causes of Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 622 Types of Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 623 Frequency of Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 63 Basic Maintenance Strategies
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 631 Run-to-Failure (Breakdown) Maintenance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 632 Scheduled (Preventative) Maintenance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 633 Condition-Based (Predictive Proactive Reliability Centered On-Condition) Maintenance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 64 Factors Which Influence Maintenance Strategy
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 65 Machine Condition Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 651 Periodic Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 652 Continuous Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 66 Transducer Selection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 661 Noncontact Displacement Transducers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 662 Velocity Transducers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 663 Acceleration Transducers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 67 Transducer Location
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 68 Recording and Analysis Instrumentation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 681 Vibration Meters
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 682 Data Collectors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 683 Frequency-Domain Analyzers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 684 Time-Domain Instruments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 685 Tracking Analyzers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 69 Display Formats and Analysis Tools
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 691 Time Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6911 Time-Waveform Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6912 Time-Waveform Indices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6913 Time-Synchronous Averaging
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6914 Negative Averaging
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6915 Orbits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6916 Probability Density Functions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6917 Probability Density Moments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 692 Frequency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6921 Band-Pass Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6922 Shock Pulse (Spike Energy)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6923 Enveloped Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6924 Signature Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6925 Cascades (Waterfall Plots)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6926 Masks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6927 Frequency-Domain Indices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 693 Modal Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 694 Quefrency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 610 Fault Detection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 6101 Standards
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61011 Standards Based on Machinery Type
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61012 Standards Based on Vibration Severity
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 6102 Acceptance Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 61021 Statistical Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 6103 Frequency-Domain Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61031 Limited Band Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61032 Constant Bandwidth Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61033 Constant Percentage Bandwidth Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 611 Fault Diagnostics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 6111 Forcing Functions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61111 Unbalance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61112 Misalignment
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61113 Mechanical Looseness
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61114 Soft Foot
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61115 Rubs
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61116 Resonances
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61117 Oil Whirl
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61118 Oil Whip
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61119 Structural Vibrations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 611110 Foundation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 6112 Specific Machine Components
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 61121 Damaged or Worn Rolling-Element Bearings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 61122 Damaged or Worn Gears
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 6113 Specific Machine Types
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61131 Pumps
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61132 Fans
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61133 Electric Motors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61134 Steam and Gas Turbines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61135 Compressors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61136 Reciprocating Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 6114 Advanced Fault Diagnostic Techniques
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 53191ch7
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • Chapter 7 Vibration-Based Tool Condition Monitoring Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 71 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 72 Mechanics of Turning
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 721 General Terms
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 722 Chatter Vibrations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 723 Tool Wear
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7231 Tool Failure Mechanisms
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7232 Tool Failure Modes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7233 Tool Wear Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7234 Tool Wear Stages
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 73 Vibration Signal Recording
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 731 Direct and Indirect Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 732 Sensor Requirements for Tool Wear Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 733 Force Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7331 Direct Measurement Dynamometers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7332 Indirect Force Sensors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7333 Piezoelectric Strain Sensors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7334 Resistance Strain Gauges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7335 Customized Force Sensors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 734 Acceleration Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 735 Acoustic Emission Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 736 Sensor Comparisons
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 74 Signal Processing for Sensor-Based Tool Condition Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 741 Feature Extraction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7411 Time Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7412 Frequency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7413 Statistical Processing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7414 TimendashFrequency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 742 Feature Selection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 75 Wear ModelDecision-Making for Sensor-Based Tool Condition Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 751 Trending Threshold
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 752 Neural Networks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7521 Unsupervised Networks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7522 Supervised Networks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 753 Fuzzy Logic
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 754 Other Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 76 Conclusion
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53191ch8
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Chapter 8 Fault Diagnosis of Helicopter Gearboxes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 81 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 82 Abnormality Scaling
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 83 The Structure-Based Connectionist Network
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 84 Sensor Location Selection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 841 Coverage Index
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 842 Overlap Index
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 843 Monitoring Effectiveness
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 85 A Case Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 851 Structural and Featural Influences
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 852 Evaluation of Influences
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 853 Fault Detection Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 854 Fault Diagnostic Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 8541 Faulty Subsystem Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 8542 Faulty Component Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 855 Sensor Location Evaluation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 856 Sensor Location Validation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 86 Conclusion
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 53191ch9
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Chapter 9 Vibration Suppression and Monitoring in Precision Motion Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 91 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 92 Mechanical Design to Minimize Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 921 Stability and Static Determinacy of Machine Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 922 Two-Dimensional Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 923 Three-Dimensional Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 93 Adaptive Notch Filter
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 931 Fast Fourier Transform
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 932 Simulation and Experiments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 94 Real-Time Vibration Analyzer
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 941 Learning Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 942 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 943 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 944 Experiments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 9441 Input Variables mdash the Evaluation Criteria
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 94411 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 94412 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 9442 Evaluation Rules
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 94421 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 94422 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 9443 Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 94431 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 94432 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 95 Practical Insights and Case Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 96 Conclusions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 53191ch10
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Chapter 10 Vibration and Shock Problems of Civil Engineering Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 101 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 102 Earthquake-Induced Vibration of Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1021 Seismicity and Ground Motions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1022 Influence of Local Site Conditions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1023 Response of Structures to Ground Motions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1024 Dynamic Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10241 Equations of Motion for Linear Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10242 Equations of Motion for Linear Multiple-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1025 Earthquake Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10251 Elastic Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10252 Smoothed Design Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10253 Ductility-Modified Response Spectrum Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1026 Design Philosophy and the Code Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10261 Performance-Based Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1027 Analysis Options for Earthquake Effects
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10271 Dynamic Time History Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10272 Response Spectrum Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 102721 Response Spectrum Analysis of Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 102722 Response Spectrum Analysis of Multi-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10273 Equivalent Static Analysis (Force-Based Approach)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10274 Displacement-Based Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1028 SoilndashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1029 Active and Passive Control Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 10210 Worked Examples
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 103 Dynamic Effects of Wind Loading on Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1031 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1032 Wind Speed
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1033 Design Structures for Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10331 Types of Wind Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10332 Design Criteria
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10333 Static Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1034 Along and Across-Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10341 Along-Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10342 Across-Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1035 Wind Tunnel Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1036 Comfort Criteria Human Response to Building Motion
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1037 Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1038 Comparison with Earthquake Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 104 Vibrations Due to Fluid ndashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1041 Added Mass and Inertial Coupling
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1042 Wave-Induced Vibration of Structure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 105 Blast Loading and Blast Effects on Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1051 Explosions and Blast Phenomenon
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1052 Explosive Air-Blast Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10521 Blast Wave Scaling Laws
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10522 Prediction of Blast Pressure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1053 Gas Explosion Loading and Effect of Internal Explosions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1054 Structural Response to Blast Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10541 Elastic Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10542 Elasto-Plastic Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1055 Material Behaviors at High Strain Rate
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10551 Dynamic Properties of Concrete under High Strain Rates
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10552 Dynamic Properties of Reinforcing Steel under High Strain Rates
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1056 Failure Modes of Blast-Loaded Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10561 Global Structural Behavior
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10562 Localized Structural Behavior
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10563 PressurendashImpulse ( PndashI ) Diagrams
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1057 Blast WavendashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1058 Effect of Ground Shocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10581 Loads from Air-Induced Ground Shock
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10582 Loads from Direct Ground Shock
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1059 Technical Design Manuals for Blast-Resistant Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 10510 Computer Programs for Blast and Shock Effects
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 106 Impact Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1061 Structural Impact between Two Bodies mdash Hard Impact and Soft Impact
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1062 Example mdash Aircraft Impact
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 107 Floor Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1071 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1072 Types of Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10721 Walking
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10722 Rhythmic Activities
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10723 Mechanical Equipment
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10724 Analysis Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1073 Natural Frequency of Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10731 Computing the Natural Frequency
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10732 Computing Deflection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10733 Damping
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10734 Resonance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1074 Vibration Caused by Walking
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10741 Minimum Natural Frequency
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1075 Design for Rhythmic Excitation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10751 Harmonics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10752 Minimum Natural Frequency
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1076 Example mdash Vibration Analysis of a Reinforced Concrete Floor
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 53191ch11
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Chapter 11 Seismic Base Isolation and Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 111 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1111 From Ductility Design to Base Isolation and Control Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1112 The Importance of Reducing Seismic Input and Response
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 112 Seismic Base Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1121 Historical Development of Base Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1122 Basic Principle
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1123 Issues in Seismic Base Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11231 Performance Criteria
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11232 Type of Structure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11233 Site Characteristics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11234 Retrofit Issues
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11235 Design of Building Services
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11236 Expected Life of Isolator
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1124 Seismic Isolation Devices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11241 Laminated Rubber Bearings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11242 Lead Rubber Bearing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11243 Friction-Based Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11244 Other Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1125 Design of Isolation Devices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11251 High-Damping Rubber Bearing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112511 Stability against Buckling
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112512 Stability against Roll Out
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11252 Lead Rubber Bearings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112521 Design of Lead Plug
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112522 Design of Laminated Rubber Bearing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11253 Design of Friction Pendulum System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1126 Verification of Properties of Isolation Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11261 Tests for Isolation Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 112611 System Characterization Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 112612 Prototype Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 112613 Quality Control Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11262 Uniform Building Code Recommendations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112621 Units Dependent on Loading Rates
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112622 Units Dependent on Bilateral Load
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112623 System Adequacy
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1127 Analysis of Base-Isolated Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11271 Modeling of a Superstructure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11272 Modeling of Isolation System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11273 Static Analysis Procedure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11274 Dynamic Analysis Procedure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 112741 Response Spectrum Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 112742 Time-History Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11275 Software for Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1128 Experimental Methods for Isolated Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1129 Implementation of Seismic Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11291 New Construction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112911 Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112912 Bridges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11292 Seismic Retrofit
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112921 Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112922 Bridges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11293 Other Implementations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 11210 Performance during Past Earthquakes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 112101 Performance of Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 112102 Performance of Bridges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 113 Seismic Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1131 Historical Development of Seismic Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1132 Basic Principles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11321 Passive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11322 Active Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11323 Semiactive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11324 Hybrid Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11325 Categorization of Basic Principles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1133 Important Issues in Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11331 SoilndashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11332 DevicendashStructure Interaction and Time Delay
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11333 Design Guidelines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1134 Vibration-Control Devices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11341 Passive Control Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113411 Metallic Yielding Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113412 Friction Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113413 Viscoelastic Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113414 Viscous Fluid Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113415 Tuned Mass Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11342 Active Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113421 Electromagnetic Actuator
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113422 Hydraulic Actuators
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11343 Semiactive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113431 Variable-Orifice Hydraulic Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113432 Controllable Fluid Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113433 Controllable Friction Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11344 Hybrid Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1135 Control Algorithm
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11351 Active Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11352 Semiactive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113521 Common Control Schemes for Controllable Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113522 Special Control Schemes for Controllable Damper
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1136 Experimental Performance Verification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11361 Shaking Table Tests of a Flexible Structural Model with TMD AMD and ATMD
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11362 Substructure Hybrid Test
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113621 Hybrid Tests Using Hydraulic Actuator
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113622 Hybrid Tests Using Shaking Table
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113623 Hybrid Tests Using Inertia-Force-Driven Loading System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1137 Implementations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11371 Semiactive Control of Full-Scale Structures Using Variable Joint Damper System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113711 Background of Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113712 Test System Set Up
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113713 Control Algorithm
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113714 Test Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11372 Application of Structural Control Technologies to Seismic Retrofit of a Cable-Stayed Bridge
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113721 Background of Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113722 Basic Concept of Seismic Retrofit
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113723 Modal Shape Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113724 Time-History Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113725 Soil ndash Structure Interaction Effect
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113726 Semiactive Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53191ch12
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Chapter 12 Seismic Random Vibration of Long-Span Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 121 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1211 Basic Concepts of Random Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12111 Stationary Random Process
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12112 Nonstationary Random Process
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1212 Three Methods for Structural Seismic Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12121 Response Spectrum Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12122 Time-History Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12123 Random Vibration Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 121231 Davenport Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 121232 Vanmarcke Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 12124 Comparisons of the Three Seismic-Analysis Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 122 Seismic Random-Excitation Fields
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1221 Power Spectral Density of Spatially Varying Ground Acceleration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1222 Several Coherence Models
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12221 FengndashHu Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12222 Harichandran ndashVanmarcke Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12223 LohndashYeh Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12224 OliveirandashHaondashPenzien Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12225 LucondashWong Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12226 QundashWangndashWang Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1223 Generation of Ground Acceleration Power Spectral Density Curves from Acceleration Response Spectrum Curves
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12231 Kaul Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12232 Iteration Scheme
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1224 Seismic Equations of Motion of Long-Span Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1225 Seismic Waves and Their Geometrical Expressions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 123 Pseudoexcitation Method for Structural Random Vibration Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1231 Structures Subjected to Stationary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12311 Single Stationary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12312 Multiple Stationary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1232 Structures Subjected to Nonstationary Random Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12321 Structures Subjected to Uniformly Modulated Evolutionary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 123211 Single Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 123212 Multiple Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12322 Structures Subjected to Nonuniformly Modulated Evolutionary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 123221 Single Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 123222 Multiple Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1233 Precise Integration Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12331 Precise Integration of Exponential Matrices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12332 Particular Solutions and Precise Integration Formulas for Various Forms of Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 123321 Linear Loading Form (HPD-L Form)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 123322 Sinusoidal Loading Form (HPD-S Form)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 123323 Exponentially Decaying Sinusoidal Loading Form (HPD-E Form)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 124 Long-Span Structures Subjected to Stationary Random Ground Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1241 The Solution of Equations of Motion Using the Pseudoexcitation Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1242 Numerical Comparisons with Other Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12421 Song-Hua-Jiang Suspension Bridge
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 124211 All Supports Move Uniformly
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 124212 Wave Passage Effect Is Taken into Account
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 124213 Wave-Passage Effect and Incoherence Effect Are Jointly Taken into Account
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 12422 San Joaquin Concrete Bridge
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 125 Long-Span Structures Subjected to Nonstationary Random Ground Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1251 Modulation Functions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1252 The Formulas for Nonstationary Multiexcitation Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1253 Expected Extreme Values of Nonstationary Random Processes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1254 Numerical Comparisons with the Corresponding Stationary Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 126 Conclusions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 53191ch13
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Chapter 13 Seismic Qualification of Equipment
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 131 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 132 Distribution Qualification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1321 Drive-Signal Generation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1322 Distribution Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1323 Test Procedures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 133 Seismic Qualification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1331 Stages of Seismic Qualification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1332 Test Preliminaries
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1333 Single-Frequency Testing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1334 Multifrequency Testing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1335 Generation of RRS Specifications
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 53191ch14
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                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Chapter 14 Human Response to Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 141 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 142 Vibration Excitations on Humans
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1421 Excitation Characteristics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 143 Human Response to Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1431 Vibration Perception
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1432 Frequency Weighting Curve
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1433 Iso-Perception Curves
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1434 Detection Threshold Curve
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 144 Regulation of Human Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1441 Acceptable Vibration Levels in Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1442 Whole-Body Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1443 HandndashArm Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
Page 4: Vibration Monitoring, Testing, and Instrumentationpreview.kingborn.net › 646000 › d1a74678d91943e5ba1d5e... · The MEMS Handbook, Second Edition MEMS: Introduction and Fundamentals

This material was previously published in Vibration and Shock Handbook copy 2005 by CRC Press LLC

CRC PressTaylor amp Francis Group6000 Broken Sound Parkway NW Suite 300Boca Raton FL 33487-2742

copy 2007 by Taylor amp Francis Group LLCCRC Press is an imprint of Taylor amp Francis Group an Informa business

No claim to original US Government worksPrinted in the United States of America on acid-free paper10987654321

International Standard Book Number-101-4200-5319-1 (Hardcover)International Standard Book Number-13978-1-4200-5319-7 (Hardcover)

This book contains information obtained from authentic and highly regarded sources Reprinted material is quotedwith permission and sources are indicated A wide variety of references are listed Reasonable efforts have been made topublish reliable data and information but the author and the publisher cannot assume responsibility for the validity ofall materials or for the consequences of their use

No part of this book may be reprinted reproduced transmitted or utilized in any form by any electronic mechanical orother means now known or hereafter invented including photocopying microfilming and recording or in any informa-tion storage or retrieval system without written permission from the publishers

For permission to photocopy or use material electronically from this work please access wwwcopyrightcom (httpwwwcopyrightcom) or contact the Copyright Clearance Center Inc (CCC) 222 Rosewood Drive Danvers MA 01923978-750-8400 CCC is a not-for-profit organization that provides licenses and registration for a variety of users For orga-nizations that have been granted a photocopy license by the CCC a separate system of payment has been arranged

Trademark Notice Product or corporate names may be trademarks or registered trademarks and are used only foridentification and explanation without intent to infringe

Library of Congress Cataloging-in-Publication Data

Vibration monitoring testing and instrumentation editor Clarence W de Silvap cm mdash (Mechanical engineering series)

Includes bibliographical references and indexISBN-13 978-1-4200-5319-7 (alk paper)ISBN-101-4200-5319-1 (alk paper)1 Vibration 2 Shock (Mechanics) I De Silva Clarence W II Title III Series

TA355V5228 200762030287-dc22 2006100139

Visit the Taylor amp Francis Web site athttpwwwtaylorandfranciscom

and the CRC Press Web site athttpwwwcrcpresscom

copy 2007 by Taylor amp Francis Group LLC

Preface

Individual chapters authored by distinguished leaders and experienced professionals in their

respective topics this book provides for engineers technicians designers researchers educators and

students a convenient thorough up-to-date and authoritative reference source on techniques tools

and data for monitoring testing and instrumentation of mechanical vibration and shock Included

are shock and vibration methodologies particularly for civil and mechanical engineering systems

instrumentation and testing methods including sensors exciters signal acquisition conditioning

and recording and LabVIEWw tools for virtual instrumentation testing and design for seismic

vibration and related regulatory issues and human response to vibration Important information

and results are summarized as windows tables graphs and lists throughout the chapters for easy

reference and information tracking References are given at the end of each chapter for further

information and study Cross-referencing is used throughout to indicate other places in the book

where further information on a particular topic is provided

In the book equal emphasis is given to theory and practical application Analytical

formulations design approaches monitoring and testing techniques and commercial software

tools are presented and illustrated Commercial equipment computer hardware and instrumenta-

tion are described analyzed and demonstrated for field application practical implementation and

experimentation Examples and case studies are given throughout the book to illustrate the use

and application of the included information The material is presented in a format that is

convenient for easy reference and recollection

Mechanical vibration is a manifestation of the oscillatory behavior in mechanical systems as a

result of either the repetitive interchange of kinetic and potential energies among components in

the system or a forcing excitation that is oscillatory Such oscillatory responses are not limited to

purely mechanical systems and are found in electrical and fluid systems as well In purely thermal

systems however free natural oscillations are not possible and an oscillatory excitation is needed

to obtain an oscillatory response Sock is vibration caused by brief abrupt and typically high-

intensity excitations Low levels of vibration mean reduced noise and improved work environment

Consequently a considerable effort is devoted today to monitoring studying and modifying the

vibration and shock generated by machinery components machine tools transit vehicles impact

processes civil engineering structures fluid flow systems and aircraft Before designing a system

for good vibratory or shock performance it is important to understand analyze and represent the

dynamic characteristics of the system This may be accomplished through monitoring testing and

analysis of test data which is the emphasis of this book

In recent years educators researchers and practitioners have devoted considerable effort towards

studying monitoring and testing vibration and shock in a range of applications in various branches

of engineering particularly civil mechanical aeronautical and aerospace and production and

v

53191mdash1432007mdash1850mdashVELUmdash246493mdash CRC ndash pp 1ndash15

copy 2007 by Taylor amp Francis Group LLC

manufacturing Specific applications are found in machine tools transit vehicles impact processes

civil engineering structures construction machinery industrial processes product qualification and

quality control fluid flow systems ships and aircraft This book is a contribution towards these

efforts

Clarence W de SilvaEditor-in-Chief

Vancouver Canada

Prefacevi

53191mdash1432007mdash1850mdashVELUmdash246493mdash CRC ndash pp 1ndash15

copy 2007 by Taylor amp Francis Group LLC

Acknowledgments

I wish to express my gratitude to the authors of the chapters for their valuable and highly professional

contributions I am very grateful to Michael Slaughter Acquisitions Editor-Engineering CRC Press for

his enthusiasm and support throughout the project Editorial and production staff at CRC Press have

done an excellent job in getting this volume out in print Finally I wish to lovingly acknowledge the

patience and understanding of my family

vii

53191mdash1432007mdash1850mdashVELUmdash246493mdash CRC ndash pp 1ndash15

copy 2007 by Taylor amp Francis Group LLC

Editor-in-Chief

Dr Clarence W de Silva PEng Fellow ASME Fellow IEEE Fellow Canadian Academy of

Engineering is Professor of Mechanical Engineering at the University of British Columbia Vancouver

Canada and has occupied the NSERC-BC Packers Research Chair in Industrial Automation since 1988

He has earned PhD degrees from the Massachusetts Institute of Technology and the University of

Cambridge England De Silva has also occupied the Mobil Endowed Chair Professorship in the

Department of Electrical and Computer Engineering at the National University of Singapore He has

served as a consultant to several companies including IBM and Westinghouse in US and has led the

development of eight industrial machines and devices He is recipient of the Henry M Paynter

Outstanding Investigator Award from the Dynamic Systems and Control Division of the American

Society of Mechanical Engineers (ASME) Killam Research Prize Lifetime Achievement Award from the

World Automation Congress Outstanding Engineering Educator Award of IEEE Canada Yasundo

Takahashi Education Award of the Dynamic Systems and Control Division of ASME IEEE Third

Millennium Medal Meritorious Achievement Award of the Association of Professional Engineers of BC

and the Outstanding Contribution Award of the Systems Man and Cybernetics Society of the Institute

of Electrical and Electronics Engineers (IEEE)

He has authored 16 technical books including Sensors and Actuators Control System Instrumentation

(Taylor amp Francis CRC Press 2007) MechatronicsmdashAn Integrated Approach (Taylor amp Francis CRC

Press Boca Raton FL 2005) Soft Computing and Intelligent Systems DesignmdashTheory Tools and

Applications (with F Karry Addison Wesley New York NY 2004) VIBRATION Fundamentals and

Practice (Taylor amp Francis CRC Press 2nd edition 2006) INTELLIGENT CONTROL Fuzzy Logic

Applications (Taylor amp Francis CRC Press 1995) Control Sensors and Actuators (Prentice Hall 1989) 14

edited volumes over 170 journal papers 200 conference papers and 12 book chapters He has served on

the editorial boards of 14 international journals in particular as the Editor-in-Chief of the International

Journal of Control and Intelligent Systems Editor-in-Chief of the International Journal of Knowledge-Based

Intelligent Engineering Systems Senior Technical Editor of Measurements and Control and Regional

Editor North America of Engineering Applications of Artificial Intelligence ndash the International Journal of

Intelligent Real-Time Automation He is a Lilly Fellow at Carnegie Mellon University NASA-ASEE Fellow

Senior Fulbright Fellow at Cambridge University ASI Fellow and a Killam Fellow Research and

development activities of Professor de Silva are primarily centered in the areas of process automation

robotics mechatronics intelligent control and sensors and actuators with cash funding of about $6

million as principal investigator

ix

53191mdash1432007mdash1850mdashVELUmdash246493mdash CRC ndash pp 1ndash15

copy 2007 by Taylor amp Francis Group LLC

Contributors

xi

Kourosh DanaiUniversity of Massachusetts

Amherst Massachusetts

Clarence W de SilvaThe University of British Columbia

Vancouver British Columbia Canada

P S HeynsUniversity of Pretoria

Pretoria South Africa

S HuangNational University of Singapore

Singapore

Hirokazu IemuraKyoto University

Kyoto Japan

Sarvesh Kumar JainMadhav Institute of Technology and

Science

Madhya Pradesh India

Christian LalanneEngineering Consultant

Jalles France

TH LeeNational University of Singapore

Singapore

YP LeowSingapore Institute of Manufacturing

Technology

Singapore

SY LimSingapore Institute of Manufacturing

Technology

Singapore

Jiaohao LinDalian University of Technology

Liaoning Peoplersquos Republic of China

W LinSingapore Institute of Manufacturing

Technology

Singapore

Chris K MechefskeQueenrsquos University

Kingston Ontario Canada

Priyan MendisUniversity of Melbourne

Melbourne Victoria Australia

Tuan NgoUniversity of Melbourne

Melbourne Victoria Australia

Mulyo Harris PradonoKyoto University

Kyoto Japan

C SchefferUniversity of Stellenbosch

Pretoria South Africa

KK TanNational University of Singapore

Singapore

KZ TangNational University of Singapore

Singapore

Yahui ZhangDalian University of Technology

Liaoning Peoplersquos Republic of China

53191mdash1432007mdash1850mdashVELUmdash246493mdash CRC ndash pp 1ndash15

copy 2007 by Taylor amp Francis Group LLC

Contents

1 Vibration Instrumentation Clarence W de Silva 1-1

11 Introduction 1-1

12 Vibration Exciters 1-3

13 Control System 1-15

14 Performance Specification 1-21

15 Motion Sensors and Transducers 1-27

16 Torque Force and Other Sensors 1-50

Appendix 1A Virtual Instrumentation for Data Acquisition Analysis

and Presentation 1-73

2 Signal Conditioning and Modification Clarence W de Silva 2-1

21 Introduction 2-2

22 Amplifiers 2-2

23 Analog Filters 2-15

24 Modulators and Demodulators 2-29

25 AnalogndashDigital Conversion 2-37

26 Bridge Circuits 2-43

27 Linearizing Devices 2-49

28 Miscellaneous Signal Modification Circuitry 2-56

29 Signal Analyzers and Display Devices 2-62

3 Vibration Testing Clarence W de Silva 3-1

31 Introduction 3-1

32 Representation of a Vibration Environment 3-3

33 Pretest Procedures 3-24

34 Testing Procedures 3-37

35 Some Practical Information 3-52

4 Experimental Modal Analysis Clarence W de Silva 4-1

41 Introduction 4-1

42 Frequency-Domain Formulation 4-2

43 Experimental Model Development 4-8

44 Curve Fitting of Transfer Functions 4-10

45 Laboratory Experiments 4-18

46 Commercial EMA Systems 4-24

xiii

53191mdash1432007mdash1850mdashVELUmdash246493mdash CRC ndash pp 1ndash15

copy 2007 by Taylor amp Francis Group LLC

5 Mechanical Shock Christian Lalanne 5-1

51 Definitions 5-2

52 Description in the Time Domain 5-3

53 Shock Response Spectrum 5-4

54 Pyroshocks 5-17

55 Use of Shock Response Spectra 5-18

56 Standards 5-24

57 Damage Boundary Curve 5-26

58 Shock Machines 5-28

59 Generation of Shock Using Shakers 5-44

510 Control by a Shock Response Spectrum 5-52

511 Pyrotechnic Shock Simulation 5-58

6 Machine Condition Monitoring and Fault Diagnostics Chris K Mechefske 6-1

61 Introduction 6-2

62 Machinery Failure 6-2

63 Basic Maintenance Strategies 6-4

64 Factors Which Influence Maintenance Strategy 6-7

65 Machine Condition Monitoring 6-8

66 Transducer Selection 6-10

67 Transducer Location 6-14

68 Recording and Analysis Instrumentation 6-14

69 Display Formats and Analysis Tools 6-16

610 Fault Detection 6-21

611 Fault Diagnostics 6-25

7 Vibration-Based Tool Condition Monitoring Systems C Scheffer and PS Heyns 7-1

71 Introduction 7-1

72 Mechanics of Turning 7-2

73 Vibration Signal Recording 7-7

74 Signal Processing for Sensor-Based Tool Condition Monitoring 7-11

75 Wear ModelDecision-Making for Sensor-Based Tool Condition Monitoring 7-15

76 Conclusion 7-20

8 Fault Diagnosis of Helicopter Gearboxes Kourosh Danai 8-1

81 Introduction 8-1

82 Abnormality Scaling 8-5

83 The Structure-Based Connectionist Network 8-8

84 Sensor Location Selection 8-11

85 A Case Study 8-14

86 Conclusion 8-23

9 Vibration Suppression and Monitoring in Precision Motion Systems KK Tan

TH Lee KZ Tang S Huang SY Lim W Lin and YP Leow 9-1

91 Introduction 9-1

92 Mechanical Design to Minimize Vibration 9-2

93 Adaptive Notch Filter 9-10

94 Real-Time Vibration Analyzer 9-17

Contentsxiv

53191mdash1432007mdash1850mdashVELUmdash246493mdash CRC ndash pp 1ndash15

copy 2007 by Taylor amp Francis Group LLC

95 Practical Insights and Case Study 9-29

96 Conclusions 9-35

10 Vibration and Shock Problems of Civil Engineering Structures Priyan Mendis

and Tuan Ngo 10-1

101 Introduction 10-2

102 Earthquake-Induced Vibration of Structures 10-3

103 Dynamic Effects of Wind Loading on Structures 10-22

104 Vibrations Due to FluidndashStructure Interaction 10-33

105 Blast Loading and Blast Effects on Structures 10-34

106 Impact Loading 10-47

107 Floor Vibration 10-51

11 Seismic Base Isolation and Vibration Control Hirokazu Iemura Sarvesh Kumar Jain

and Mulyo Harris Pradono 11-1

111 Introduction 11-1

112 Seismic Base Isolation 11-4

113 Seismic Vibration Control 11-33

12 Seismic Random Vibration of Long-Span Structures Jiahao Lin and Yahui Zhang 12-1

121 Introduction 12-2

122 Seismic Random-Excitation Fields 12-11

123 Pseudoexcitation Method for Structural Random Vibration Analysis 12-16

124 Long-Span Structures Subjected to Stationary Random Ground Excitations 12-27

125 Long-Span Structures Subjected to Nonstationary Random Ground Excitations 12-34

126 Conclusions 12-39

13 Seismic Qualification of Equipment Clarence W de Silva 13-1

131 Introduction 13-1

132 Distribution Qualification 13-1

133 Seismic Qualification 13-6

14 Human Response to Vibration Clarence W de Silva 14-1

141 Introduction 14-1

142 Vibration Excitations on Humans 14-2

143 Human Response to Vibration 14-3

144 Regulation of Human Vibration 14-6

Contents xv

53191mdash1432007mdash1850mdashVELUmdash246493mdash CRC ndash pp 1ndash15

copy 2007 by Taylor amp Francis Group LLC

1Vibration

Instrumentation

Clarence W de SilvaThe University of British Columbia

11 Introduction 1-1

12 Vibration Exciters 1-3Shaker Selection dagger Dynamics of Electromagnetic Shakers

13 Control System 1-15Components of a Shaker Controller dagger Signal-Generating

Equipment

14 Performance Specification 1-21Parameters for Performance Specification dagger Linearity dagger

Instrument Ratings dagger Accuracy and Precision

15 Motion Sensors and Transducers 1-27Potentiometer dagger Variable-Inductance Transducers dagger

Mutual-Induction Proximity Sensor dagger Selfinduction

Transducers dagger Permanent-Magnet Transducers dagger

Alternating Current Permanent-Magnet Tachometer dagger

Alternating Current Induction Tachometer dagger Eddy Current

Transducers dagger Variable-Capacitance Transducers dagger

Piezoelectric Transducers

16 Torque Force and Other Sensors 1-50Strain Gage Sensors dagger Miscellaneous Sensors

Appendix 1A Virtual Instrumentation for DataAcquisition Analysis and Presentation 1-73

Summary

Devices useful in instrumenting a mechanical vibrating system are presented in this chapter Shakers whichgenerate vibration excitations are discussed and compared A variety of sensors including motion sensorsproximity sensors forcetorque sensors and other miscellaneous sensors are considered Performance specificationin the time domain and the frequency domain is addressed Rating parameters of instruments are given

11 Introduction

Measurement and associated experimental techniques play a significant role in the practice of vibration

Academic exposure to vibration instrumentation usually arises in laboratories in the context of learning

training and research In vibration practice perhaps the most important task of instrumentation is the

measurement or sensing of vibration Vibration sensing is useful in the following applications

1 Design and development of a product

2 Testing (screening) of a finished product for quality assurance

3 Qualification of a good-quality product to determine its suitability for a specific application

1-1

53191mdash522007mdash1201mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

4 Mechanical aging of a product prior to carrying out a test program

5 Exploratory testing of a product to determine its dynamic characteristics such as resonances

mode shapes and even a complete dynamic model

6 Vibration monitoring for performance evaluation

7 Control and suppression of vibration

Figure 11 indicates a procedure typical of experimental vibration highlighting the essential

instrumentation Vibrations are generated in a device the test object in response to some excitation In

some experimental procedures primarily in vibration testing (see Figure 11) the excitation signal has

to be generated in a signal generator in accordance with some requirement (specification) and applied to

the object through an exciter after amplification and conditioning In some other situations primarily in

performance monitoring and vibration control the excitations are generated as an integral part of the

operating environment of the vibrating object and may originate either within the object (eg engine

excitations in an automobile) or in the environment with which the object interacts during operation

(eg road disturbances on an automobile) Sensors are needed to measure vibrations in the test object In

particular a control sensor is used to check whether the specified excitation is applied to the object

and one or more response sensors may be used to measure the resulting vibrations at key locations of

the object

The sensor signals have to be properly conditioned for example by filtering and amplification and

modified for example through modulation demodulation and analog-to-digital conversion prior to

recording analyzing and display The purpose of the controller is to guarantee that the excitation is

correctly applied to the test object If the signal from the control sensor deviates from the required

excitation the controller modifies the signal to the exciter so as to reduce this deviation Furthermore the

controller will stabilize or limit (compress) the vibrations in the object It follows that instruments in

experimental vibration may be generally classified into the following categories

1 Signal-generating devices

2 Vibration exciters

3 Sensors and transducers

4 Signal conditioningmodifying devices

5 Signal analysis devices

6 Control devices

7 Vibration recording and display devices

AnalogDigital

Interface

DigitalSignal

RecorderAnalyzerDisplay

FilterAmplifier

FilterAmplifier

SignalGenerator

and ExciterController

Reference (Required)Signal (Specification)

PowerAmplifier

MountingFixtures

TestObject

ResponseSensor

ControlSensor

Exciter

SwivelBase

FIGURE 11 Typical instrumentation in experimental vibration

Vibration Monitoring Testing and Instrumentation1-2

53191mdash522007mdash1201mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

Note that one instrument may perform the tasks

of more than one category listed here Also more

than one instrument may be needed to carry out

tasks in a single category In the following sections

we will provide some examples of the types of

vibration instrumentation giving characteristics

operating principles and important practical

considerations Also we will describe several

experiments which can be found in a typical

vibration laboratory

An experimental vibration system generally

consists of four main subsystems

1 Test object

2 Excitation system

3 Control system

4 Signal acquisition and modification system

These are schematically shown in Figure 12 Note that various components shown in Figure 11 may

be incorporated into one of these subsystems In particular component matching hardware and object

mounting fixtures may be considered interfacing devices that are introduced through the interaction

between the main subsystems as shown in Figure 12 Some important issues of vibration testing and

instrumentation are summarized in Box 11

12 Vibration Exciters

Vibration experimentation may require an external exciter to generate the necessary vibration This is the

case in controlled experiments such as product testing where a specified level of vibration is applied to the

test object and the resulting response is monitored A variety of vibration exciters are available with

different capabilities and principles of operation

Three basic types of vibration exciters (shakers) are widely used hydraulic shakers inertial shakers

and electromagnetic shakers The operation-capability ranges of typical exciters in these three categories

are summarized in Table 11 Stroke or maximum displacement is the largest displacement the exciter

is capable of imparting onto a test object whose weight is assumed to be within its design load limit

Maximum velocity and acceleration are similarly defined Maximum force is the largest force that could

be applied by the shaker to a test object of acceptable weight (one within the design load) The values

given in Table 11 should be interpreted with caution Maximum displacement is achieved only at very

low frequencies The achievement of maximum velocity corresponds to intermediate frequencies in the

operating frequency range of the shaker Maximum acceleration and force ratings are usually achieved at

high frequencies It is not feasible for example to operate a vibration exciter at its maximum

displacement and its maximum acceleration simultaneously

Consider a loaded exciter that is executing harmonic motion Its displacement is given by

x frac14 s sin vt eth11THORN

in which s is the displacement amplitude (or stroke) Corresponding velocity and acceleration are

_x frac14 sv cos vt eth12THORN

eurox frac14 2sv2sin vt eth13THORN

SignalModification

System

TestObject

ControlSystem

VibrationExciter (Shaker)

System

FIGURE 12 Interactions between major subsystems of

an experimental vibration system

Vibration Instrumentation 1-3

53191mdash522007mdash1201mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

If the velocity amplitude is denoted by v and the acceleration amplitude by a it follows from Equation

12 and Equation 13 thatv frac14 vs eth14THORN

and

a frac14 vv eth15THORN

Box 11

VIBRATION INSTRUMENTATION

Vibration Testing Applications for Products

Design and Development Production Screening and Quality Assessment Utilization and Qualification for Special Applications

Testing Instrumentation

Exciter (excites the test object) Controller (controls the exciter for accurate excitation) Sensors and Transducers (measure excitations and responses and provide excitation error

signals to controller) Signal Conditioning (converts signals to appropriate form) Recording and Display (perform processing storage and documentation)

Exciters

Shakers

1 Electrodynamic (high bandwidth moderate power complex and multifrequency

excitations)

2 Hydraulic (moderate to high bandwidth high power complex and multifrequency

excitations)

3 Inertial (low bandwidth low power single-frequency harmonic excitations)

TransientInitial Condition

1 Hammers (impulsive bump tests)

2 Cable Release (step excitations)

3 Drop (impulsive)

Signal Conditioning

Filters Amplifiers Amplifiers ModulatorsDemodulators ADCDAC

Sensors

Motion (displacement velocity acceleration) Force (strain torque)

Vibration Monitoring Testing and Instrumentation1-4

53191mdash522007mdash1201mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

TABLE 11 Typical Operation-Capability Ranges for Various Shaker Types

Shaker Type Typical Operational Capabilities

Frequency Maximum Displacement

(Stroke)

Maximum

Velocity

Maximum

Acceleration

Maximum

Force

Excitation

Waveform

Hydraulic

(electrohydraulic)

Low

(01ndash500 Hz)

High (20 in 50 cm) Intermediate

(50 insec

125 cmsec)

Intermediate

(20 g)

High (100000 lbf

450000 N)

Average flexibility (simple

to complex and random)

Inertial

(counter-rotating mass)

Intermediate

(2ndash50 Hz)

Low (1 in 25 cm) Intermediate

(50 insec

125 cmsec)

Intermediate

(20 g)

Intermediate

(1000 lbf 4500 N)

Sinusoidal only

Electromagnetic

(electrodynamic)

High

(2ndash10000 Hz)

Low (1 in 25 cm) Intermediate

(50 insec

125 cmsec)

High (100 g) Low to intermediate

(450 lbf 2000 N)

High flexibility and accuracy

(simple to complex and

random)

VibrationInstru

mentation

1-5

53191mdash522007mdash

1201mdashSENTHILKUMARmdash246494mdash

CRCndashpp1ndash112

copy 2007 by Taylor amp Francis Group LLC

An idealized performance curve of a shaker

has a constant displacementndashamplitude region a

constant velocityndashamplitude region and a con-

stant accelerationndashamplitude region for low

intermediate and high frequencies respectively

in the operating frequency range Such an ideal

performance curve is shown in Figure 13(a) on a

frequencyndashvelocity plane Logarithmic axes are

used In practice typical shaker performance

curves would be fairly smooth yet nonlinear

curves similar to those shown in Figure 13(b)

As the mass increases the performance curve

compresses Note that the acceleration limit of a

shaker depends on the mass of the test object

(load) Full load corresponds to the heaviest object

that could be tested The ldquono loadrdquo condition

corresponds to a shaker without a test object To

standardize the performance curves they are

usually defined at the rated load of the shaker A

performance curve in the frequencyndashvelocity

plane may be converted to a curve in the

frequencyndashacceleration plane simply by increasing

the slope of the curve by a unit magnitude (ie

20 dbdecade)

Several general observations can be made from

Equation 14 and Equation 15 In the constant-

peak displacement region of the performance

curve the peak velocity increases proportionally

with the excitation frequency and the peak

acceleration increases with the square of the excitation frequency In the constant-peak velocity region

the peak displacement varies inversely with the excitation frequency and the peak acceleration increases

proportionately In the constant-peak acceleration region the peak displacement varies inversely with the

square of the excitation frequency and the peak velocity varies inversely with the excitation frequency

This further explains why rated stroke maximum velocity and maximum acceleration values are not

simultaneously realized

121 Shaker Selection

Vibration testing is accomplished by applying a specified excitation to the test package using a shaker

apparatus and monitoring the response of the test object Test excitation may be represented by its

response spectrum The test requires that the response spectrum of the actual excitation known as the

test response spectrum (TRS) envelops the response spectrum specified for the particular test known as

the required response spectrum (RRS)

A major step in the planning of any vibration testing program is the selection of a proper shaker

(exciter) system for a given test package The three specifications that are of primary importance in

selecting a shaker are the force rating the power rating and the stroke (maximum displacement) rating

Force and power ratings are particularly useful in moderate to high frequency excitations and the stroke

rating is the determining factor for low frequency excitations In this section a procedure is given to

determine conservative estimates for these parameters in a specified test for a given test package

Frequency domain considerations are used here

Stroke

Limit M

ax

Acceleration

MaxVelocity

Peak

Vel

ocity

(cm

s)

01 1 10 100

FullLoad

NoLoad

Frequency (Hz)(a)

Peak

Vel

ocity

(cm

s)

100

10

1

100

10

1

01 1 10 100

FullLoad

NoLoad

Frequency (Hz)(b)

FIGURE 13 Performance curve of a vibration exciter

in the frequencyndashvelocity plane (log) (a) ideal (b)

typical

Vibration Monitoring Testing and Instrumentation1-6

53191mdash522007mdash1201mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

1211 Force Rating

In the frequency domain the (complex) force at the exciter (shaker) head is given by

F frac14 mHethvTHORNasethvTHORN eth16THORNin which v is the excitation frequency variable m is the total mass of the test package including

mounting fixture and attachments asethvTHORN is the Fourier spectrum of the support-location (exciter head)

acceleration and H(v) is frequency response function that takes into account the flexibility and

damping effects (dynamics) of the test package apart from its inertia In the simplified case where the

test package can be represented by a simple oscillator of natural frequency vn and damping ratio by zt

this function becomes

HethvTHORN frac14 1thorn 2jztv=vn=12 ethv=vnTHORN2 thorn 2jztv=vn eth17THORNin which j frac14 ffiffiffiffi

21p

This approximation is adequate for most practical purposes The static weight of the

test object is not included in Equation 16 Most heavy-duty shakers which are typically hydraulic

have static load support systems such as pneumatic cushion arrangements that can exactly balance the

dead load The exciter provides only the dynamic force In cases where shaker directly supports the

gravity load in the vertical test configuration Equation 16 should be modified by adding a term to

represent this weight

A common practice in vibration test applications is to specify the excitation signal by its response

spectrum This is simply the peak response of a simple oscillator expressed as a function of its natural

frequency when its support location is excited by the specified signal Clearly the damping of the simple

oscillator is an added parameter in a response spectrum specification Typical damping ratios ethzrTHORN used inresponse spectra specifications are less than 01 (or 10) It follows that an approximate relationship

between the Fourier spectrum of the support acceleration and its response spectrum is

as frac14 2jzrarethvTHORN eth18THORNThe magnitude larethvTHORNl is the response spectrumEquation 18 substituted into Equation 16 gives

F frac14 mHethvTHORN2jzrarethvTHORN eth19THORNIn view of Equation 17 for test packages having low damping the peak value of H(v) is

approximately 1=eth2jztTHORN this should be used in computing the force rating if the test package has a

resonance within the frequency range of testing On the other hand if the test package is assumed to be

rigid then HethvTHORN oslash 1 A conservative estimate for the force rating is

Fmax frac14 methzr=ztTHORNlarethvTHORNlmax eth110THORNIt should be noted that larethvTHORNlmax is the peak value of the specified (required) response spectrum (RRS)

for acceleration

1212 Power Rating

The exciter head does not develop its maximum force when driven at maximum velocity Output power

is determined by using

p frac14 Refrac12FvsethvTHORN eth111THORNin which vsethvTHORN is the Fourier spectrum of the exciter velocity and Re [ ] denotes the real part of a complex

function Note that as frac14 jvvs Substituting Equation 16 and Equation 18 into Equation 111 gives

p frac14 eth4mz2r =vTHORNRefrac12jHethvTHORNa2r ethvTHORN eth112THORNIt follows that a conservative estimate for the power rating is

pmax frac14 2methz2r =ztTHORNfrac12larethvTHORNl2=v max eth113THORN

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Representative segments of typical acceleration RRS curves have slope n as given by

a frac14 k1vn eth114THORN

It should be clear from Equation 113 that the maximum output power is given by

pmax frac14 k2v2n21 eth115THORN

This is an increasing function for n 1=2 and a decreasing function for n 1=2 It follows that the power

rating corresponds to the highest point of contact between the acceleration RRS curve and a line of slope

equal to 12 A similar relationship may be derived if velocity RRS curves (having slopes n2 1) are used

1213 Stroke Rating

From Equation 18 it should be clear that the Fourier spectrum xs of the exciter displacement time

history can be expressed as

xs frac14 2zrarethvTHORN=jv2 eth116THORNAn estimate for stroke rating is

xmax frac14 2zrfrac12larethvTHORNl=v2 max eth117THORNThis is of the form

xmax frac14 kvn22 eth118THORNIt follows that the stroke rating corresponds to the highest point of contact between the acceleration

RRS curve and a line of slope equal to two

Example 11

A test package of overall mass 100 kg is to be

subjected to dynamic excitation represented by the

acceleration RRS (at 5 damping) as shown in

Figure 14 The estimated damping of the test

package is 7 The test package is known to have a

resonance within the frequency range of the

specified test Determine the exciter specifications

for the test

Solution

From the development presented in the previous

section it is clear that the point F (or P) in

Figure 14 corresponds to the force and output

power ratings and the point S corresponds to

the stroke rating The co-ordinates of these

critical points are F P frac14 eth42 Hz 40 gTHORN and S frac14 eth08 Hz 075 gTHORN Equation 110 gives the force

rating as

Fmax frac14 100 pound eth005=007THORN pound 40 pound 981 N frac14 2803 N

Equation 113 gives the power rating as

pmax frac14 2 pound 100 pound eth0052=007THORN pound frac12eth40 pound 981THORN2=42 pound 2p watts frac14 417 W

Equation 117 gives the stroke rating as

xmax frac14 2 pound 005 pound frac12eth075 pound 98THORN=eth08 pound 2pTHORN2 m frac14 3 cm

Acc

eler

atio

n(g

)

Con

stan

t Dis

plac

emen

t

Constant Velo

city

Frequency (Hz)

S

FP

0101

10 10 100

10

10

FIGURE 14 Test excitation specified by an accelera-

tion RRS (5 damping)

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1214 Hydraulic Shakers

A typical hydraulic shaker consists of a piston-cylinder arrangement (also called a ram) a servo-valve a

fluid pump and a driving electric motor Hydraulic fluid (oil) is pressurized (typical operating pressure

4000 psi) and pumped into the cylinder through a servo-valve by means of a pump that is driven by an

electric motor (typical power 150 hp) The flow (typical rate 100 galmin) that enters the cylinder is

controlled (modulated) by the servo-valve which in effect controls the resulting piston (ram) motion

A typical servo-valve consists of a two-stage spool valve which provides a pressure difference and a

controlled (modulated) flow to the piston which sets it in motion

The servo-valve itself is moved by means of a linear torque motor which is driven by the excitation-

input signal (electrical) A primary function of the servo-valve is to provide a stabilizing feedback to the

ram In this respect the servo-valve complements the main control system of the test setup The ram is

coupled to the shaker table by means of a link with some flexibility The cylinder frame is mounted on the

support foundation with swivel joints This allows for some angular and lateral misalignment which

might be caused primarily by test-object dynamics as the table moves

Two-degree-of-freedom (Two-DoF) testing requires two independent sets of actuators and three-DoF

testing requires three independent actuator sets Each independent actuator set can consist of several

actuators operated in parallel using the same pump and the same excitation-input signal to the torque

motors

If the test table is directly supported on the vertical actuators they must withstand the total dead

weight (ie the weight of the test table the test object the mounting fixtures and the instrumentation)

This is requirement is usually prevented by providing a pressurized air cushion in the gap between the

test table and the foundation walls Air should be pressurized so as to balance the total dead weight

exactly (typical required gage pressure 3 psi)

Figure 15(a) shows the basic components of a typical hydraulic shaker The corresponding

operational block diagram is shown in Figure 15(b) It is desirable to locate the actuators in a pit in the

test laboratory so that the test tabletop is flushed with the test laboratory floor under no-load conditions

This minimizes the effort required to place the test object on the test table Otherwise the test object has

to be lifted onto the test table with a forklift Also installation of an aircushion to support the system

dead weight is difficult under these circumstances of elevated mounting

Hydraulic actuators are most suitable for heavy load testing and are widely used in industrial and civil

engineering applications They canbeoperated at very low frequencies (almost direct current [DC]) aswell

as at intermediate frequencies (see Table 11) Large displacements (stroke) are possible at low frequencies

Hydraulic shakers have the advantage of providing high flexibility of operation during the test their

capabilities include variable-force and constant-force testing and wide-band random-input testing The

velocity and acceleration capabilities of hydraulic shakers are moderate Although any general excitation-

input motion (for example sine wave sine beat wide-band random) can be used in hydraulic shakers

faithful reproduction of these signals is virtually impossible at high frequencies because of distortion and

higher-order harmonics introduced by the high noise levels that are common in hydraulic systems This

is only a minor drawback in heavy-duty intermediate-frequency applications Dynamic interactions are

reduced through feedback control

1215 Inertial Shakers

In inertial shakers or ldquomechanical excitersrdquo the force that causes the shaker-table motion is generated by

inertia forces (accelerating masses) Counter-rotating-mass inertial shakers are typical in this category

To understand their principle of operation consider two equal masses rotating in opposite directions at

the same angular speed v and in the same circle of radius r (see Figure 16) This produces a resultant

force equal to 2mv2r cos vt in a fixed direction (the direction of symmetry of the two rotating arms)

Consequently a sinusoidal force with a frequency of v and an amplitude proportional to v2 is generated

This reaction force is applied to the shaker table

Figure 17 shows a sketch of a typical counter-rotating-mass inertial shaker It consists of two identical

rods rotating at the same speed in opposite directions Each rod has a series of slots in which to

Vibration Instrumentation 1-9

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copy 2007 by Taylor amp Francis Group LLC

place weights In this manner the magnitude of

the eccentric mass can be varied to achieve various

force capabilities The rods are driven by a

variable-speed electric motor through a gear

mechanism that usually provides several speed

ratios A speed ratio is selected depending on the

required test-frequency range The whole system is

symmetrically supported on a carriage that is

directly connected to the test table The test object

is mounted on the test table The preferred

mounting configuration is horizontal so that the

excitation force is applied to the test object in a

horizontal direction In this configuration there

are no variable gravity moments (weight pounddistance to center of gravity) acting on the drive

mechanism Figure 17 shows the vertical con-

figuration In dynamic testing of large structures

the carriage can be mounted directly on the

structure at a location where the excitation force

should be applied By incorporating two pairs of

counter-rotating masses it is possible to generate

test moments as well as test forces

FIGURE 15 A typical hydraulic shaker arrangement (a) schematic diagram (b) operational block diagram

m m

2mw2r cos wt

wtw w

wt

FIGURE 16 Principle of operation of a counter-

rotating-mass inertial shaker

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Reaction-type shakers driven by inertia are widely used for the prototype testing of civil engineering

structures Their first application dates back to 1935 Inertial shakers are capable of producing

intermediate excitation forces The force generated is limited by the strength of the carriage frame The

frequency range of operation and the maximum velocity and acceleration capabilities are also

intermediate for inertial shakers whereas the maximum displacement capability is typically low A major

limitation of inertial shakers is that their excitation force is exclusively sinusoidal and that the force

amplitude is directly proportional to the square of the excitation frequency As a result complex and

random excitation testing constant-force testing (for example transmissibility tests and constant-force

sine-sweep tests) and flexibility to vary the force amplitude or the displacement amplitude during a test

are not generally feasible with this type of shakers Excitation frequency and amplitude can be varied

during testing however by incorporating a variable-speed drive for the motor The sinusoidal excitation

generated by inertial shakers is virtually undistorted which gives them an advantage over the other types

of shakers when used in sine-dwell and sine-sweep tests Small portable shakers with low-force capability

are available for use in on-site testing

1216 Electromagnetic Shakers

In electromagnetic shakers or ldquoelectrodynamic excitersrdquo the motion is generated using the principle of

operation of an electric motor Specifically the excitation force is produced when a variable excitation

signal (electrical) is passed through a moving coil placed in a magnetic field

The components of a commercial electromagnetic shaker are shown in Figure 18 A steady magnetic

field is generated by a stationary electromagnet that consists of field coils wound on a ferromagnetic base

that is rigidly attached to a protective shell structure The shaker head has a coil wound around it When

the excitation electrical signal is passed through this drive coil the shaker head which is supported on

flexure mounts will be set in motion The shaker head consists of the test table on which the test object

is mounted Shakers with interchangeable heads are available The choice of appropriate shaker head is

based on the geometry and mounting features of the test object The shaker head can be turned to

different angles by means of a swivel joint In this manner different directions of excitation (in biaxial

and triaxial testing) can be obtained

FIGURE 17 Sketch of a counter-rotating-mass inertial shaker

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122 Dynamics of Electromagnetic Shakers

Consider a single axis electromagnetic shaker (Figure 18) with a test object having a single natural

frequency of importance within the test frequency range The dynamic interactions between the shaker

and the test object give rise to two significant natural frequencies (and correspondingly two significant

resonances) These appear as peaks in the frequency response curve of the test setup Furthermore the

natural frequency (resonance) of the test package alone causes a ldquotroughrdquo or depression (antiresonance)

in the frequency response curve of the overall test setup To explain this characteristic consider the

dynamic model shown in Figure 19 The following mechanical parameters are defined for

Figure 19(a) m k and b are the mass stiffness and equivalent viscous damping constant respectively

of the test package and me ke and be are the corresponding parameters of the exciter (shaker) Also in

the equivalent electrical circuit of the shaker head as shown in Figure 19(b) the following electrical

parameters are defined Re and Le are the resistance and (leakage) inductance and kb is the back

electromotive force (back emf) of the linear motor Assuming that the gravitational forces are supported

FIGURE 18 Schematic sectional view of a typical electromagnetic shaker manufactured by Bruel and Kjaer

Denmark

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by the static deflections of the flexible elements and that the displacements are measured from the static

equilibrium position we have the following system equations

Test object meuroy frac14 2kethy2 yeTHORN2 beth_y2 _yeTHORN eth119THORNShaker head me euroye frac14 fe thorn kethy2 yeTHORN thorn beth_y2 _yeTHORN2 key 2 be _ye eth120THORN

Electrical Lediedt

thorn Reie thorn kb _ye frac14 vethtTHORN eth121THORN

The electromagnetic force fe generated in the shaker head is a result of the interaction of the magnetic

field generated by the current ie with coil of the moving shaker head and the constant magnetic field

(stator) in which the head coil is located Here we have

fe frac14 kbie eth122THORNNote that v(t) is the voltage signal that is applied by the amplifier to the shaker coil ye is the displacement

of the shaker head and y is the displacement response of the test package

It is assumed that kb has consistent electrical and mechanical units (Vmsec and NA) Usually

the electrical time constant of the shaker is quite small compared with the primarily mechanical

time constants of the shaker and the test package In such cases the Ledie=dt term in Equation 121 may

be neglected Consequently the equations from Equation 119 through Equation 122 may be

expressed in the Laplace (frequency) domain with the Laplace variable s taking the place of the derivative

d=dt as

ethms2 thorn bsthorn kTHORNy frac14 ethbsthorn kTHORNye eth123THORN

FIGURE 19 Dynamic models of an electromagnetic shaker and a flexible test package (a) mechanical model

(b) electrical model

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copy 2007 by Taylor amp Francis Group LLC

frac12mes2 thorn ethbthorn beTHORNsthorn ethkthorn keTHORN ye frac14 ethbsthorn kTHORNy thorn kb

Rev2

k2bs

Reye eth124THORN

It follows that the transfer function of the shaker head motion with respect to the excitation voltage is

given by

yevfrac14 kb

Re

DethsTHORNDdethsTHORN eth125THORN

where DethsTHORN is the characteristic function of the primary dynamics of the test object

DethsTHORN frac14 ms2 thorn bsthorn k eth126THORN

and DdethsTHORN is the characteristic function of the primary dynamic interactions between the shaker and thetest object

DcethsTHORN frac14 mmes4 thorn frac12methbe thorn bthorn boTHORN thornmeb s

3 thorn frac12methke thorn kTHORN thornmekthorn bethbe thorn boTHORN s2thorn frac12bke thorn ethbe thorn boTHORNk sthorn kke

eth127THORN

where

bo frac14 k2bRe

eth128THORN

It is clear that under low damping conditions DdethsTHORN will produce two resonances as it is fourth order in sand similarly DethsTHORN will produce one antiresonance (trough) corresponding to the resonance of the testobject Note that in the frequency domain s frac14 jv and hence the frequency response function given by

Equation 125 is in fact

yevfrac14 kb

Rb

DethjvTHORNDdethjvTHORN eth129THORN

The magnitude of this frequency response function for a typical test system is sketched in Figure 110

Note that this curve is for the ldquoopen-looprdquo case where there is no feedback from the shaker controller

In practice the shaker controller will be able

to compensate for the resonances and anti-

resonances to some degree depending on its

effectiveness

The main advantages of electromagnetic

shakers are their high frequency range of

operation their high degree of operating flexi-

bility and the high level of accuracy of the

generated shaker motion Faithful reproduction

of complex excitations is possible because of the

advanced electronics and control systems used in

this type of shakers Electromagnetic shakers are

not suitable for heavy-duty applications (large test

objects) however High test-input accelerations

are possible at high frequencies when electromag-

netic shakers are used but their displacement and

velocity capabilities are limited to low or

intermediate values (see Table 11)

100

10

1 10 100Excitation Frequency (Hz)

Antiresonance

Resonance

Shak

erD

ispl

acem

entM

agni

tude

Resonance

1000

FIGURE 110 Frequency response curve of a typical

electromagnetic shaker with a test object

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1221 Transient Exciters

Other varieties of exciters are commonly used in

transient-type vibration testing In these tests

either an impulsive force or an initial excitation is

applied to the test object and the resulting

response is monitored The excitations and the

responses are ldquotransientrdquo in this case Hammer

test drop tests and pluck tests fall into this

category For example a hammer test may be

conducted by hitting the object with an instru-

mented hammer and then measuring the response

of the object The hammer has a force sensor at its

tip as sketched in Figure 111 A piezoelectric or

strain-gage type force sensor may be used More

sophisticated hammers have impedance heads in

place of force sensors An impedance head

measures force and acceleration simultaneously

The results of a hammer test will depend on many

factors for example the dynamics of the hammer

body how firmly the hammer is held during the

impact how quickly the impact is applied and

whether there are multiple impacts

13 Control System

The two primary functions of the shaker control system in vibration testing are (1) to guarantee that the

specified excitation is applied to the test object and (2) to ensure that the dynamic stability (motion

constraints) of the test setup is preserved An operational block diagram illustrating these control

functions is given in Figure 112 The reference input to the control system represents the desired

excitation force that should be applied to the test object In the absence of any control however the force

reaching the test object will be distorted primarily because of (1) dynamic interactions and

nonlinearities of the shaker the test table the mounting fixtures the auxiliary instruments and the test

object itself (2) noise and errors in the signal generator amplifiers filters and other equipment and (3)

external loads and disturbances acting on the test object and other components (for example external

restraints aerodynamic forces friction) To compensate for these distorting factors response

measurements (displacements velocities acceleration and so on) are made at various locations in the

test setup and are used to control the system dynamics In particular the responses of the shaker the test

table and the test object are measured These responses are used to compare the actual excitation felt by

FIGURE 111 An instrumented hammer used in bump

tests or hammer tests

ExcitationInput

(Reference)

Feedback Paths

DriveSignal

ShakerResponse

TestTable

TestObject

Test ObjectResponse

Test TableResponseExciter

(Shaker)(Ram)

Controllerand

Amplifier

FIGURE 112 Operational block diagram illustrating a general shaker control system

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the test object at the shaker interface with the desired (specified) input The drive signal to the shaker is

modified depending on the error that is present

Two types of control are commonly employed in shaker apparatus simple manual control and

complex automatic control Manual control normally consists of simple open-loop trial-and-error

methods of manual adjustments (or calibration) of the control equipment to obtain a desired dynamic

response The actual response is usually monitored (on an oscilloscope or frequency analyzer screen for

example) during manual-control operations The pretest adjustments in manual control can be very

time-consuming as a result the test object might be subjected to overtesting which could produce

cumulative damage is undesirable and could defeat the test purpose Furthermore the calibration

procedure for the experimental setup must be repeated for each new test object

The disadvantages ofmanual control suggest that automatic control is desirable in complex test schemes

in which high accuracy of testing is desired The first step of automatic control involves automatic

measurement of the system response using control sensors and transducers The measurement is then fed

back into the control system which instantaneously determines the best drive signal to actuate the shaker

in order to get the desired excitation This may be done by either analog or digital methods

Primitive control systems require an accurate mathematical description of the test object This

dependency of the control system on the knowledge of test-object dynamics is clearly undesirable

Performance of a good control system should not be considerably affected by the dynamic interactions

and nonlinearities of the test object or by the nature of the excitation Proper selection of feedback signals

and control-system components can reduce such effects and will make the system robust

In the response-spectrum method of vibration testing it is customary to use displacement control at

low frequencies velocity control at intermediate frequency and acceleration control at high frequencies

This necessitates feedback of displacement velocity and acceleration responses Generally however the

most important feedback is the velocity feedback In sine-sweep tests the shaker velocity must change

steadily over the frequency band of interest In particular the velocity control must be precise near the

resonances of the test object Velocity (speed) feedback has a stabilizing effect on the dynamics which is

desirable This effect is particularly useful in ensuring stability in motion when testing is done near

resonances of lightly damped test objects On the contrary displacement (position) feedback can have a

destabilizing effect on some systems particularly when high feedback gains are used

The controller usually consists of various instruments equipment and computation hardware and

software Often the functions of the data-acquisition and processing system overlap with those of the

controller to some extent As an example consider the digital-controller of vibration testing apparatus

First the responses are measured through sensors (and transducers) filtered and amplified

(conditioned) These data channels may be passed through a multiplexer whose purpose is to select

one data channel at a time for processing Most modern data acquisition hardware does not need a

separate multiplexer to handle multiple signals The analog data are converted into digital data using

analog-to-digital converters (ADCs) The resulting sampled data are stored on a disk or as a block data in

the computer memory The reference input signal (typically a signal recorded on an FM tape) is also

sampled (if it is not already in the digital form) using an ADC and fed into the computer Digital

processing is done on the reference signal and the response data with the objective of computing the

command signal to drive the shaker The digital command signal is converted into an analog signal using

a digital-to-analog converter (DAC) and amplified (conditioned) before it is used to drive the exciter

The nature of the control components depends to a large extent on the nature and objectives of the

particular test to be conducted Some of the basic components in a shaker controller are described in

the following subsections

131 Components of a Shaker Controller

1311 Compressor

A compressor circuit is incorporated in automatic excitation control devices to control the excitation-

input level automatically The level of control depends on the feedback signal from a control sensor and

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the specified (reference) excitation signal Usually the compressor circuit is included in the excitation-

signal generator (for example in a sine generator) The control by this means may be done on the basis of

a single-frequency component (eg the fundamental frequency)

1312 Equalizer (Spectrum Shaper)

Random-signal equalizers are used to shape the spectrum of a random signal in a desired manner In

essence and equalizer consists of a bank of narrow-band filters (for example 80 filters) in parallel over

the operating frequency range By passing the signal through each filter the spectral density (or the mean

square value) of the signal in that narrow frequency band (for example each one-third-octave band) is

determined This is compared with the desired spectral level and automatic adjustment is made in that

filter in case there is an error In some systems response-spectrum analysis is made in place of power

spectral density analysis In that case the equalizer consists of a bank of simple oscillators whose

resonant frequencies are distributed over the operating frequency range of the equalizer The feedback

signal is passed through each oscillator and the peak value of its output is determined This value is

compared with the desired response spectrum value at that frequency If there is an error automatic gain

adjustment is made in the appropriate excitation signal components

Random-noise equalizers are used in conjunction with random signal generators They receive

feedback signals from the control sensors In some digital control systems there are algorithms (software)

that are used to iteratively converge the spectrum of the excitation signal felt by the test object into the

desired spectrum

1313 Tracking Filter

Many vibration tests are based on single-frequency excitations In such cases the control functions

should be performed on the basis of the amplitudes of the fundamental-frequency component of the

signal A tracking filter is simply a frequency-tuned band-pass filter It automatically tunes the center

frequency of its very narrow-band-pass filter to the frequency of a carrier signal Then when a noisy

signal is passed through the tuned filter the output of the filter will be the required fundamental

frequency component in the signal Tracking filters also are useful in obtaining amplitudendashfrequency

plots using an XndashY plotter In such cases the frequency value comes from the signal generator (sweep

oscillator) which produces the carrier signal to the tracking filter The tracking filter then determines the

corresponding amplitude of a signal that is fed into it Most tracking filters have dual channels so that two

signals can be handled (tracked) simultaneously

1314 Excitation Controller (Amplitude Servo-Monitor)

An excitation controller is typically an integral part of the signal generator It can be set so that automatic

sweep between two frequency limits can be performed at a selected sweep rate (linear or logarithmic)

More advanced excitation controllers have the capability of an automatic switch-over between constant-

displacement constant-velocity and constant-acceleration excitation-input control at specified

frequencies over the sweep frequency interval Consequently integrator circuits should be present

within the excitation controller unit to determine velocities and displacements from acceleration signals

Sometimes integration is performed by a separate unit called a vibration meter This unit also offers

the operator the capability of selecting the desired level of each signal (acceleration velocity or

displacement) There is an automatic cut-off level for large displacement values that could result from

noise in acceleration signals A compressor is also a subcomponent of the excitation controller The

complete unit is sometimes known as an amplitude servo-monitor

132 Signal-Generating Equipment

Shakers are force-generating devices that are operated using drive (excitation) signals generated from a

source The excitation-signal source is known as the signal generator Three major types of signal

generators are used in vibration testing applications (1) oscillators (2) random-signal generators and

(3) storage devices In some units oscillators and random-signal generators are combined We shall

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copy 2007 by Taylor amp Francis Group LLC

discuss these two generators separately however because of their difference in function It also should be

noted that almost any digital signal (deterministic or random) can be generated by a digital computer

using a suitable computer program the signal eventually can be passed through a DAC to obtain

the corresponding analog signal These lsquodigitalrsquo signal generators along with analog sources such as

magnetic tape players (FM) are classified into the category of storage devices

The dynamic range of equipment is the ratio of the maximum and minimum output levels (expressed

in decibels) at which it is capable of operating without significant error This is an important specification

for many types of equipment particularly for signal-generating devices The output level of the signal

generator should be set to a value within its dynamic range

1321 Oscillators

Oscillators are essentially single-frequency generators Typically sine signals are generated but other

waveforms (such as rectangular and triangular pulses) are also available in most oscillators Normally

an oscillator has two modes of operation (1) sweeping up and down between two frequency limits and

(2) dwelling at a specified frequency In the sweep operation the sweep rate should be specified This can

be done either on a linear scale (Hzmin) or on a logarithmic scale (octavesmin) In the dwell operation

the frequency points (or intervals) should be specified In either case a desired signal level can be chosen

using the gain-control knob An oscillator that is operated exclusively in the sweep mode is called a sweep

oscillator

The early generation of oscillators employed variable inductor-capacitor types of electronic circuits to

generate signals oscillating at a desired frequency The oscillator is tuned to the required frequency by

varying the capacitance or inductance parameters A DC voltage is applied to energize the capacitor

and to obtain the desired oscillating voltage signal which subsequently is amplified and conditioned

Modern oscillators use operational amplifier circuits along with resistor capacitor and semiconductor

(SC) elements Also common are crystal (quartz) parallel-resonance oscillators used to generate voltage

signals accurately at a fixed frequency The circuit is activated using a DC-voltage source Other

frequencies of interest are obtained by passing this high-frequency signal through a frequency converter

The signal is then conditioned (amplified and filtered) Required shaping (for example rectangular

pulse) is obtained using a shape circuit Finally the required signal level is obtained by passing the

resulting signal through a variable-gain amplifier A block diagram of an oscillator illustrating various

stages in the generation of a periodic signal is given in Figure 113

A typical oscillator offers a choice of several (typically six) linear and logarithmic frequency ranges and

a sizable level of control capability (for example 80 dB) Upper and lower frequency limits in a sweep can

be preset on the front panel to any of the available frequency ranges Sweep-rate settings are continuously

DC Voltage

Oscillator

FrequencySpecification

FrequencyConverter

FilterAmplifier

ShaperPeriodicSignal

FrequencyCounter

Fixed-FrequencySignal

Variable-GainOutput

Amplifier

SignalSpecification

LevelSpecification

FIGURE 113 Block diagram of an oscillator-type signal generator

Vibration Monitoring Testing and Instrumentation1-18

53191mdash522007mdash1202mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

  • 53191fm
    • Vibration Monitoring Testing and Instrumentation
      • Preface
      • Acknowledgments
      • Editor-in-Chief
      • Contributors
      • Contents
      • Related Titles
          • 53191ch1
            • Table of Contents
            • Chapter 1 Vibration Instrumentation
              • Summary
              • 11 Introduction
              • 12 Vibration Exciters
                • 121 Shaker Selection
                  • 1211 Force Rating
                  • 1212 Power Rating
                  • 1213 Stroke Rating
                  • 1214 Hydraulic Shakers
                  • 1215 Inertial Shakers
                  • 1216 Electromagnetic Shakers
                    • 122 Dynamics of Electromagnetic Shakers
                      • 1221 Transient Exciters
                          • 13 Control System
                            • 131 Components of a Shaker Controller
                              • 1311 Compressor
                              • 1312 Equalizer (Spectrum Shaper)
                              • 1313 Tracking Filter
                              • 1314 Excitation Controller (Amplitude Servo-Monitor)
                                • 132 Signal-Generating Equipment
                                  • 1321 Oscillators
                                  • 1322 Random Signal Generators
                                  • 1323 Tape Players
                                  • 1324 Data Processing
                                      • 14 Performance Specification
                                        • 141 Parameters for Performance Specification
                                          • 1411 Time-Domain Specifications
                                          • 1412 Frequency-Domain Specifications
                                            • 142 Linearity
                                            • 143 Instrument Ratings
                                              • 1431 Rating Parameters
                                                • 144 Accuracy and Precision
                                                  • 15 Motion Sensors and Transducers
                                                    • 151 Potentiometer
                                                      • 1511 Potentiometer Resolution
                                                      • 1512 Optical Potentiometer
                                                        • 152 Variable-Inductance Transducers
                                                          • 1521 Mutual-Induction Transducers
                                                          • 1522 Linear-Variable Differential Transformer
                                                          • 1523 Signal Conditioning
                                                            • 153 Mutual-Induction Proximity Sensor
                                                            • 154 Selfinduction Transducers
                                                            • 155 Permanent-Magnet Transducers
                                                            • 156 Alternating Current Permanent-Magnet Tachometer
                                                            • 157 Alternating Current Induction Tachometer
                                                            • 158 Eddy Current Transducers
                                                            • 159 Variable-Capacitance Transducers
                                                              • 1591 Capacitive Displacement Sensors
                                                              • 1592 Capacitive Angular Velocity Sensor
                                                              • 1593 Capacitance Bridge Circuit
                                                                • 1510 Piezoelectric Transducers
                                                                  • 15101 Sensitivity
                                                                  • 15102 Piezoelectric Accelerometer
                                                                  • 15103 Charge Amplifier
                                                                      • 16 Torque Force and Other Sensors
                                                                        • 161 Strain Gage Sensors
                                                                          • 1611 Equations for Strain Gage Measurements
                                                                          • 1612 Bridge Sensitivity
                                                                          • 1613 The Bridge Constant
                                                                          • 1614 The Calibration Constant
                                                                          • 1615 Data Acquisition
                                                                          • 1616 Accuracy Considerations
                                                                          • 1617 Semiconductor Strain Gages
                                                                          • 1618 Force and Torque Sensors
                                                                          • 1619 Strain Gage Torque Sensors
                                                                          • 16110 Deflection Torque Sensors
                                                                          • 16111 Variable-Reluctance Torque Sensor
                                                                          • 16112 Reaction Torque Sensors
                                                                            • 162 Miscellaneous Sensors
                                                                              • 1621 Stroboscope
                                                                              • 1622 Fiber Optic Sensors and Lasers
                                                                              • 1623 Fiber-Optic Gyroscope
                                                                              • 1624 Laser Doppler Interferometer
                                                                              • 1625 Ultrasonic Sensors
                                                                              • 1626 Gyroscopic Sensors
                                                                                  • References
                                                                                  • Appendix 1A Virtual Instrumentation for Data Acquisition Analysis and Presentation
                                                                                    • Summary
                                                                                    • List of Abbreviations
                                                                                    • 1A1 Dynamic Signals
                                                                                      • 1A11 Acquiring and Simulating Dynamic Signals
                                                                                        • 1A111 Aliasing
                                                                                        • 1A112 Time Continuity
                                                                                            • 1A2 Measurement Configuration Considerations
                                                                                              • 1A21 Input Signal Considerations
                                                                                                • 1A211 Input Pseudodifferential and Differential Configuration
                                                                                                • 1A212 Gain
                                                                                                • 1A213 Input Coupling
                                                                                                • 1A214 Integrated Electronic Piezoelectric Excitation
                                                                                                • 1A215 Nyquist Frequency and Bandwidth
                                                                                                • 1A216 Analog-to-Digital Conversion
                                                                                                • 1A217 Antialias Filters
                                                                                                • 1A218 Input Filter Delay
                                                                                                • 1A219 Overload Detection
                                                                                                  • 1A22 Output Signal Considerations
                                                                                                    • 1A221 Output Pseudodifferential and Differential Configuration
                                                                                                    • 1A222 Attenuation
                                                                                                    • 1A223 Digital-to-Analog Conversion
                                                                                                    • 1A224 Anti-imaging and Interpolation Filters
                                                                                                    • 1A225 Output Filter Delay
                                                                                                        • 1A3 Scaling and Calibration
                                                                                                          • 1A31 Scaling to Engineering Units
                                                                                                          • 1A32 Performing System Calibration
                                                                                                            • 1A321 Propagation Delay Calibration
                                                                                                                • 1A4 Limit Testing Analysis
                                                                                                                  • 1A41 Limit Testing Overview
                                                                                                                  • 1A42 Using the SVT Limit Testing VI
                                                                                                                    • 1A5 Integration
                                                                                                                      • 1A51 Introduction to Integration
                                                                                                                      • 1A52 Implementing Integration
                                                                                                                        • 1A521 Challenges when Integrating Vibration Data
                                                                                                                          • 1A53 Time-Domain Integration
                                                                                                                            • 1A531 Single-Shot Acquisition and Integration
                                                                                                                            • 1A532 Continuous Acquisition and Integration
                                                                                                                              • 1A54 Frequency-Domain Integration
                                                                                                                                • 1A6 Vibration-Level Measurements
                                                                                                                                  • 1A61 Measuring the Root Mean Square Level
                                                                                                                                    • 1A611 Single-Shot Buffered Acquisition
                                                                                                                                    • 1A612 Continuous Signal Acquisition
                                                                                                                                      • 1A62 Performing a Running RMS Level Measurement
                                                                                                                                      • 1A63 Computing the Peak Level
                                                                                                                                      • 1A64 Computing the Crest Factor
                                                                                                                                        • 1A7 Frequency Analysis
                                                                                                                                          • 1A71 FFT Fundamentals
                                                                                                                                            • 1A711 Number of Samples
                                                                                                                                            • 1A712 Frequency Resolution
                                                                                                                                            • 1A713 Maximum Resolvable Frequency
                                                                                                                                            • 1A714 Minimum Resolvable Frequency
                                                                                                                                            • 1A715 Number of Spectral Lines
                                                                                                                                            • 1A716 Relationship between Time-Domain and Frequency-Domain Specifications and Parameters
                                                                                                                                              • 1A72 Increasing Frequency Resolution
                                                                                                                                                • 1A721 Zoom FFT Analysis
                                                                                                                                                • 1A722 Frequency Resolution of the Zoom FFT VIs
                                                                                                                                                • 1A723 Zoom Measurement
                                                                                                                                                • 1A724 Zoom Settings
                                                                                                                                                • 1A725 Subset Analysis
                                                                                                                                                    • 1A8 Transient Analysis
                                                                                                                                                      • 1A81 Transient Analysis with the Sound and Vibration Toolkit
                                                                                                                                                      • 1A82 Performing an STFT vs Time
                                                                                                                                                        • 1A821 Selecting the FFT Block Size
                                                                                                                                                        • 1A822 Overlapping
                                                                                                                                                        • 1A823 Using the SVT STFT vs Time VI
                                                                                                                                                          • 1A83 Performing an STFT vs Rotational Speed
                                                                                                                                                            • 1A831 Converting the Pulse Train to Rotational Speed
                                                                                                                                                            • 1A832 STFT vs RPM
                                                                                                                                                              • 1A84 Measuring a Shock Response Spectrum
                                                                                                                                                                • 1A9 Waterfall Display
                                                                                                                                                                  • 1A91 Using the Display VIs
                                                                                                                                                                    • 1A911 Initializing the Display
                                                                                                                                                                    • 1A912 Sending Data to the Display
                                                                                                                                                                    • 1A913 Waterfall Display for Frequency Analysis
                                                                                                                                                                    • 1A914 Waterfall Display for Transient Analysis
                                                                                                                                                                    • 1A915 Waterfall Display for Octave Spectra
                                                                                                                                                                        • 1A10 Swept-Sine Measurements
                                                                                                                                                                          • 1A101 Swept-Sine Overview
                                                                                                                                                                          • 1A102 Choosing Swept-Sine vs FFT Measurements
                                                                                                                                                                          • 1A103 Taking a Swept-Sine Measurement
                                                                                                                                                                          • 1A104 Swept-Sine Measurement Example
                                                                                                                                                                              • Bibliography
                                                                                                                                                                              • Related Titles
                                                                                                                                                                                  • 53191ch2
                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                    • Chapter 2 Signal Conditioning and Modification
                                                                                                                                                                                      • Summary
                                                                                                                                                                                      • 21 Introduction
                                                                                                                                                                                      • 22 Amplifiers
                                                                                                                                                                                        • 221 Operational Amplifier
                                                                                                                                                                                        • 222 Use of Feedback in Opamp
                                                                                                                                                                                        • 223 Voltage Current and Power Amplifiers
                                                                                                                                                                                          • 2231 Charge Amplifiers
                                                                                                                                                                                            • 224 Instrumentation Amplifiers
                                                                                                                                                                                              • 2241 Differential Amplifier
                                                                                                                                                                                              • 2242 Common Mode
                                                                                                                                                                                                • 225 Amplifier Performance Ratings
                                                                                                                                                                                                  • 2251 Common-Mode Rejection Ratio
                                                                                                                                                                                                    • 226 Component Interconnection
                                                                                                                                                                                                      • 2261 Impedance Characteristics
                                                                                                                                                                                                      • 2262 Cascade Connection of Devices
                                                                                                                                                                                                      • 2263 AC-Coupled Ampliers
                                                                                                                                                                                                          • 23 Analog Filters
                                                                                                                                                                                                            • 231 Passive Filters and Active Filters
                                                                                                                                                                                                              • 2311 Number of Poles
                                                                                                                                                                                                                • 232 Low-Pass Filters
                                                                                                                                                                                                                  • 2321 Low-Pass Butterworth Filter
                                                                                                                                                                                                                    • 233 High-Pass Filters
                                                                                                                                                                                                                    • 234 Band-Pass Filters
                                                                                                                                                                                                                      • 2341 Resonance-Type Band-Pass Filters
                                                                                                                                                                                                                        • 235 Band-Reject Filters
                                                                                                                                                                                                                          • 24 Modulators and Demodulators
                                                                                                                                                                                                                            • 241 Amplitude Modulation
                                                                                                                                                                                                                              • 2411 Modulation Theorem
                                                                                                                                                                                                                              • 2412 Side Frequencies and Side Bands
                                                                                                                                                                                                                                • 242 Application of Amplitude Modulation
                                                                                                                                                                                                                                  • 2421 Fault Detection and Diagnosis
                                                                                                                                                                                                                                    • 243 Demodulation
                                                                                                                                                                                                                                      • 25 Analog ndashDigital Conversion
                                                                                                                                                                                                                                        • 251 Digital-to-Analog Conversion
                                                                                                                                                                                                                                          • 2511 DAC Error Sources
                                                                                                                                                                                                                                            • 252 Analog-to-Digital Conversion
                                                                                                                                                                                                                                            • 253 Analog-to-Digital Converter Performance Characteristics
                                                                                                                                                                                                                                              • 2531 Resolution and Quantization Error
                                                                                                                                                                                                                                              • 2532 Monotonicity Nonlinearity and Offset Error
                                                                                                                                                                                                                                              • 2533 Analog-to-Digital Converter Conversion Rate
                                                                                                                                                                                                                                                • 254 Sample-and-Hold Circuitry
                                                                                                                                                                                                                                                • 255 Digital Filters
                                                                                                                                                                                                                                                  • 2551 Software Implementation and Hardware Implementation
                                                                                                                                                                                                                                                      • 26 Bridge Circuits
                                                                                                                                                                                                                                                        • 261 Wheatstone Bridge
                                                                                                                                                                                                                                                        • 262 Constant-Current Bridge
                                                                                                                                                                                                                                                        • 263 Bridge Amplifiers
                                                                                                                                                                                                                                                          • 2631 Half-Bridge Circuits
                                                                                                                                                                                                                                                            • 264 Impedance Bridges
                                                                                                                                                                                                                                                              • 2641 Owen Bridge
                                                                                                                                                                                                                                                              • 2642 Wien-Bridge Oscillator
                                                                                                                                                                                                                                                                  • 27 Linearizing Devices
                                                                                                                                                                                                                                                                    • 271 Linearization by Software
                                                                                                                                                                                                                                                                    • 272 Linearization by Hardware Logic
                                                                                                                                                                                                                                                                    • 273 Analog Linearizing Circuitry
                                                                                                                                                                                                                                                                    • 274 Offsetting Circuitry
                                                                                                                                                                                                                                                                    • 275 Proportional-Output Circuitry
                                                                                                                                                                                                                                                                      • 2751 Curve-Shaping Circuitry
                                                                                                                                                                                                                                                                          • 28 Miscellaneous Signal Modification Circuitry
                                                                                                                                                                                                                                                                            • 281 Phase Shifters
                                                                                                                                                                                                                                                                            • 282 Voltage-to-Frequency Converter
                                                                                                                                                                                                                                                                            • 283 Frequency-to-Voltage Converter
                                                                                                                                                                                                                                                                            • 284 Voltage-to-Current Converters
                                                                                                                                                                                                                                                                            • 285 Peak-Hold Circuits
                                                                                                                                                                                                                                                                              • 29 Signal Analyzers and Display Devices
                                                                                                                                                                                                                                                                                • 291 Signal Analyzers
                                                                                                                                                                                                                                                                                • 292 Oscilloscopes
                                                                                                                                                                                                                                                                                  • 2921 Triggering
                                                                                                                                                                                                                                                                                  • 2922 Lissajous Patterns
                                                                                                                                                                                                                                                                                  • 2923 Digital Oscilloscopes
                                                                                                                                                                                                                                                                                      • Bibliography
                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                          • 53191ch3
                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                            • Chapter 3 Vibration Testing
                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                              • 31 Introduction
                                                                                                                                                                                                                                                                                              • 32 Representation of a Vibration Environment
                                                                                                                                                                                                                                                                                                • 321 Test Signals
                                                                                                                                                                                                                                                                                                  • 3211 Stochastic vs Deterministic Signals
                                                                                                                                                                                                                                                                                                    • 322 Deterministic Signal Representation
                                                                                                                                                                                                                                                                                                      • 3221 Single-Frequency Signals
                                                                                                                                                                                                                                                                                                      • 3222 Sine Sweep
                                                                                                                                                                                                                                                                                                      • 3223 Sine Dwell
                                                                                                                                                                                                                                                                                                      • 3224 Decaying Sine
                                                                                                                                                                                                                                                                                                      • 3225 Sine Beat
                                                                                                                                                                                                                                                                                                      • 3226 Sine Beat with Pauses
                                                                                                                                                                                                                                                                                                      • 3227 Multifrequency Signals
                                                                                                                                                                                                                                                                                                      • 3228 Actual Excitation Records
                                                                                                                                                                                                                                                                                                      • 3229 Simulated Excitation Signals
                                                                                                                                                                                                                                                                                                        • 323 Stochastic Signal Representation
                                                                                                                                                                                                                                                                                                          • 3231 Ergodic Random Signals
                                                                                                                                                                                                                                                                                                          • 3232 Stationary Random Signals
                                                                                                                                                                                                                                                                                                          • 3233 Independent and Uncorrelated Signals
                                                                                                                                                                                                                                                                                                          • 3234 Transmission of Random Excitations
                                                                                                                                                                                                                                                                                                            • 324 Frequency-Domain Representations
                                                                                                                                                                                                                                                                                                              • 3241 Fourier Spectrum Method
                                                                                                                                                                                                                                                                                                              • 3242 Power Spectral Density Method
                                                                                                                                                                                                                                                                                                                • 325 Response Spectrum
                                                                                                                                                                                                                                                                                                                  • 3251 Displacement Velocity and Acceleration Spectra
                                                                                                                                                                                                                                                                                                                  • 3252 Response-Spectra Plotting Paper
                                                                                                                                                                                                                                                                                                                  • 3253 Zero-Period Acceleration
                                                                                                                                                                                                                                                                                                                  • 3254 Uses of Response Spectra
                                                                                                                                                                                                                                                                                                                    • 326 Comparison of Various Representations
                                                                                                                                                                                                                                                                                                                      • 33 Pretest Procedures
                                                                                                                                                                                                                                                                                                                        • 331 Purpose of Testing
                                                                                                                                                                                                                                                                                                                        • 332 Service Functions
                                                                                                                                                                                                                                                                                                                          • 3321 Active Equipment
                                                                                                                                                                                                                                                                                                                          • 3322 Passive Equipment
                                                                                                                                                                                                                                                                                                                          • 3323 Functional Testing
                                                                                                                                                                                                                                                                                                                            • 333 Information Acquisition
                                                                                                                                                                                                                                                                                                                              • 3331 Interface Details
                                                                                                                                                                                                                                                                                                                              • 3332 Effect of Neglecting Interface Dynamics
                                                                                                                                                                                                                                                                                                                              • 3333 Effects of Damping
                                                                                                                                                                                                                                                                                                                              • 3334 Effects of Inertia
                                                                                                                                                                                                                                                                                                                              • 3335 Effect of Natural Frequency
                                                                                                                                                                                                                                                                                                                              • 3336 Effect of Excitation Frequency
                                                                                                                                                                                                                                                                                                                              • 3337 Other Effects of Interface
                                                                                                                                                                                                                                                                                                                                • 334 Test-Program Planning
                                                                                                                                                                                                                                                                                                                                  • 3341 Testing of Cabinet-Mounted Equipment
                                                                                                                                                                                                                                                                                                                                    • 335 Pretest Inspection
                                                                                                                                                                                                                                                                                                                                      • 34 Testing Procedures
                                                                                                                                                                                                                                                                                                                                        • 341 Resonance Search
                                                                                                                                                                                                                                                                                                                                        • 342 Methods of Determining Frequency-Response Functions
                                                                                                                                                                                                                                                                                                                                          • 3421 Fourier Transform Method
                                                                                                                                                                                                                                                                                                                                          • 3422 Spectral Density Method
                                                                                                                                                                                                                                                                                                                                          • 3423 Harmonic Excitation Method
                                                                                                                                                                                                                                                                                                                                            • 343 Resonance-Search Test Methods
                                                                                                                                                                                                                                                                                                                                              • 3431 Hammer (Bump) Test and Drop Test
                                                                                                                                                                                                                                                                                                                                              • 3432 Pluck Test
                                                                                                                                                                                                                                                                                                                                              • 3433 Shaker Tests
                                                                                                                                                                                                                                                                                                                                                • 344 Mechanical Aging
                                                                                                                                                                                                                                                                                                                                                  • 3441 Equivalence for Mechanical Aging
                                                                                                                                                                                                                                                                                                                                                  • 3442 Excitation-Intensity Equivalence
                                                                                                                                                                                                                                                                                                                                                  • 3443 Dynamic-Excitation Equivalence
                                                                                                                                                                                                                                                                                                                                                  • 3444 Cumulative Damage Theory
                                                                                                                                                                                                                                                                                                                                                    • 345 Test-Response Spectrum Generation
                                                                                                                                                                                                                                                                                                                                                    • 346 Instrument Calibration
                                                                                                                                                                                                                                                                                                                                                    • 347 Test-Object Mounting
                                                                                                                                                                                                                                                                                                                                                    • 348 Test-Input Considerations
                                                                                                                                                                                                                                                                                                                                                      • 3481 Test Nomenclature
                                                                                                                                                                                                                                                                                                                                                      • 3482 Testing with Uncorrelated Excitations
                                                                                                                                                                                                                                                                                                                                                      • 3483 Symmetrical Rectilinear Testing
                                                                                                                                                                                                                                                                                                                                                      • 3484 Geometry vs Dynamics
                                                                                                                                                                                                                                                                                                                                                      • 3485 Some Limitations
                                                                                                                                                                                                                                                                                                                                                      • 3486 Testing Black Boxes
                                                                                                                                                                                                                                                                                                                                                      • 3487 Phasing of Excitations
                                                                                                                                                                                                                                                                                                                                                      • 3488 Testing a Gray or White Box
                                                                                                                                                                                                                                                                                                                                                      • 3489 Overtesting in Multitest Sequences
                                                                                                                                                                                                                                                                                                                                                          • 35 Some Practical Information
                                                                                                                                                                                                                                                                                                                                                            • 351 Random Vibration Test Example
                                                                                                                                                                                                                                                                                                                                                            • 352 Vibration Shakers and Control Systems
                                                                                                                                                                                                                                                                                                                                                              • Bibliography
                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                  • 53191ch4
                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                    • Chapter 4 Experimental Modal Analysis
                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                      • 41 Introduction
                                                                                                                                                                                                                                                                                                                                                                      • 42 Frequency-Domain Formulation
                                                                                                                                                                                                                                                                                                                                                                        • 421 Transfer-Function Matrix
                                                                                                                                                                                                                                                                                                                                                                        • 422 Principle of Reciprocity
                                                                                                                                                                                                                                                                                                                                                                          • 43 Experimental Model Development
                                                                                                                                                                                                                                                                                                                                                                            • 431 Extraction of the Time-Domain Model
                                                                                                                                                                                                                                                                                                                                                                              • 44 Curve Fitting of Transfer Functions
                                                                                                                                                                                                                                                                                                                                                                                • 441 Problem Identification
                                                                                                                                                                                                                                                                                                                                                                                • 442 Single- and Multi-Degree-of-Freedom Techniques
                                                                                                                                                                                                                                                                                                                                                                                • 443 Single-Degree-of-Freedom Parameter Extraction in the Frequency Domain
                                                                                                                                                                                                                                                                                                                                                                                  • 4431 Circle-Fit Method
                                                                                                                                                                                                                                                                                                                                                                                    • Case of Viscous Damping
                                                                                                                                                                                                                                                                                                                                                                                    • Case of Hysteretic Damping
                                                                                                                                                                                                                                                                                                                                                                                      • 4432 Peak-Picking Method
                                                                                                                                                                                                                                                                                                                                                                                        • 444 Multi-Degree of Freedom Curve Fitting
                                                                                                                                                                                                                                                                                                                                                                                          • 4441 Formulation of the Method
                                                                                                                                                                                                                                                                                                                                                                                            • 445 A Comment on Static Modes and Rigid-Body Modes
                                                                                                                                                                                                                                                                                                                                                                                            • 446 Residue Extraction
                                                                                                                                                                                                                                                                                                                                                                                              • 45 Laboratory Experiments
                                                                                                                                                                                                                                                                                                                                                                                                • 451 Lumped-Parameter System
                                                                                                                                                                                                                                                                                                                                                                                                  • 4511 Frequency-Domain Test
                                                                                                                                                                                                                                                                                                                                                                                                  • 4512 Time-Domain Tests
                                                                                                                                                                                                                                                                                                                                                                                                    • 452 Distributed-Parameter System
                                                                                                                                                                                                                                                                                                                                                                                                      • 46 Commercial EMA Systems
                                                                                                                                                                                                                                                                                                                                                                                                        • 461 System Configuration
                                                                                                                                                                                                                                                                                                                                                                                                          • 4611 FFT Analysis Options
                                                                                                                                                                                                                                                                                                                                                                                                          • 4612 Modal Analysis Components
                                                                                                                                                                                                                                                                                                                                                                                                              • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                  • 53191ch5
                                                                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                    • Chapter 5 Mechanical Shock
                                                                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                      • 51 Definitions
                                                                                                                                                                                                                                                                                                                                                                                                                        • 511 Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 512 Simple (or Perfect) Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 513 Half-Sine Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 514 Versed-Sine (or Haversine) Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 515 Terminal Peak Sawtooth Shock or Final Peak Sawtooth Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 516 Rectangular Shock
                                                                                                                                                                                                                                                                                                                                                                                                                          • 5161 Trapezoidal Shock
                                                                                                                                                                                                                                                                                                                                                                                                                              • 52 Description in the Time Domain
                                                                                                                                                                                                                                                                                                                                                                                                                              • 53 Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                • 531 Need
                                                                                                                                                                                                                                                                                                                                                                                                                                • 532 Shock Response Spectrum Definition
                                                                                                                                                                                                                                                                                                                                                                                                                                • 533 Response of a Linear One-Degree-of-Freedom System
                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5331 Shock Defined by a Force
                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5332 Shock Defined by an Acceleration
                                                                                                                                                                                                                                                                                                                                                                                                                                    • 534 Definitions
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5341 Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5342 Absolute Acceleration Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5343 Relative Displacement Shock Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5344 Primary Positive Shock Response Spectrum or Initial Positive Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5345 Primary (or Initial) Negative Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5346 Secondary (or Residual) Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5347 Positive (or Maximum Positive) Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5348 Negative (or Maximum Negative) Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5349 Maximax Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53410 Choice of Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                        • 535 Standardized Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5351 Definition
                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5352 Standardized Shock Response Spectra of Simple Shocks
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53521 Half-Sine Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53522 Versed Sine Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53523 Terminal Peak Sawtooth Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53524 Rectangular Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53525 Trapezoidal Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 536 Choice of Damping
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 537 Shock Response Spectra Domains
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 538 Algorithms for Calculation of the Shock Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 539 Choice of the Digitization Frequency of the Signal
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5310 Use of Shock Response Spectra for the Study of Systems with Several Degrees of Freedom
                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 54 Pyroshocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 55 Use of Shock Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 551 Severity Comparison of Several Shocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 552 Test Specification Development from Real Environment Data
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5521 Synthesis of Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5522 Nature of the Specification
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5523 Choice of Shape
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5524 Amplitude
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5525 Duration
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5526 Difficulties
                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 56 Standards
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 561 Types of Standards
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 562 Installation Conditions of Test Item
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 563 Uncertainty Factor
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 564 Bump Test
                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 57 Damage Boundary Curve
                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 571 Definition
                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 572 Analysis of Test Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 58 Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 581 Main Types
                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 582 Impact Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5821 Universal Shock-Test Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 58211 Impact Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 58212 Impulse Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 583 Shock Simulators (Programmers)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5831 Half-Sine Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58311 Shock Duration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58312 Impact Velocity
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58313 Maximum Deformation of the Shock Simulator (Programmer)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58314 Shock Amplitude
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58315 Characteristics of the Target
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5832 Terminal Peak Sawtooth Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5833 Rectangular Pulse ndash Trapezoidal Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5834 Universal Shock Simulator (Programmer)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 58341 Generating a Half-Sine Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 58342 Generating a Terminal Peak Sawtooth Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 58343 Trapezoidal Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 584 Limitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5841 Limitations of the Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5842 Limitations of Shock Simulators
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 585 Pneumatic Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 586 High Impact Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5861 Lightweight High Impact Shock Machine
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5862 Medium Weight High Impact Shock Machine
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 587 Specific Test Facilities
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 59 Generation of Shock Using Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 591 Principle Behind the Generation of a Simple Shape Signal versus Time
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 592 Main Advantages
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 593 Pre- and Postshocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5931 Requirements
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5932 Solutions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 59321 Optimized Pre- and Postpulses
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5933 Incidence on the Shock Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 594 Limitations of Electrodynamic Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5941 Mechanical Limitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 59411 Abacuses
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5942 Electronic Limitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 595 The Use of Electrohydraulic Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 510 Control by a Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 5101 Principle
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 5102 Principal Shapes of Elementary Signals
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 51021 Decaying Sinusoid
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 51022 ZERD Function
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 51023 WAVSIN Waveform
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 5103 Comparison of WAVSIN SHOC Waveforms and Decaying Sinusoid
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 5104 Criticism of Control by a Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 511 Pyrotechnic Shock Simulation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5111 Simulation Using Pyrotechnic Facilities
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5112 Simulation Using Metal-to-Metal Impact
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5113 Simulation Using Electrodynamic Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5114 Simulation Using Conventional Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53191ch6
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Chapter 6 Machine Condition Monitoring and Fault Diagnostics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 61 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 62 Machinery Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 621 Causes of Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 622 Types of Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 623 Frequency of Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 63 Basic Maintenance Strategies
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 631 Run-to-Failure (Breakdown) Maintenance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 632 Scheduled (Preventative) Maintenance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 633 Condition-Based (Predictive Proactive Reliability Centered On-Condition) Maintenance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 64 Factors Which Influence Maintenance Strategy
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 65 Machine Condition Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 651 Periodic Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 652 Continuous Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 66 Transducer Selection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 661 Noncontact Displacement Transducers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 662 Velocity Transducers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 663 Acceleration Transducers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 67 Transducer Location
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 68 Recording and Analysis Instrumentation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 681 Vibration Meters
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 682 Data Collectors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 683 Frequency-Domain Analyzers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 684 Time-Domain Instruments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 685 Tracking Analyzers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 69 Display Formats and Analysis Tools
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 691 Time Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6911 Time-Waveform Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6912 Time-Waveform Indices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6913 Time-Synchronous Averaging
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6914 Negative Averaging
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6915 Orbits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6916 Probability Density Functions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6917 Probability Density Moments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 692 Frequency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6921 Band-Pass Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6922 Shock Pulse (Spike Energy)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6923 Enveloped Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6924 Signature Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6925 Cascades (Waterfall Plots)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6926 Masks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6927 Frequency-Domain Indices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 693 Modal Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 694 Quefrency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 610 Fault Detection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 6101 Standards
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61011 Standards Based on Machinery Type
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61012 Standards Based on Vibration Severity
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 6102 Acceptance Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 61021 Statistical Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 6103 Frequency-Domain Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61031 Limited Band Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61032 Constant Bandwidth Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61033 Constant Percentage Bandwidth Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 611 Fault Diagnostics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 6111 Forcing Functions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61111 Unbalance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61112 Misalignment
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61113 Mechanical Looseness
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61114 Soft Foot
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61115 Rubs
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61116 Resonances
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61117 Oil Whirl
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61118 Oil Whip
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61119 Structural Vibrations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 611110 Foundation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 6112 Specific Machine Components
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 61121 Damaged or Worn Rolling-Element Bearings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 61122 Damaged or Worn Gears
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 6113 Specific Machine Types
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61131 Pumps
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61132 Fans
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61133 Electric Motors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61134 Steam and Gas Turbines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61135 Compressors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61136 Reciprocating Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 6114 Advanced Fault Diagnostic Techniques
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 53191ch7
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • Chapter 7 Vibration-Based Tool Condition Monitoring Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 71 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 72 Mechanics of Turning
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 721 General Terms
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 722 Chatter Vibrations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 723 Tool Wear
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7231 Tool Failure Mechanisms
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7232 Tool Failure Modes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7233 Tool Wear Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7234 Tool Wear Stages
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 73 Vibration Signal Recording
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 731 Direct and Indirect Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 732 Sensor Requirements for Tool Wear Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 733 Force Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7331 Direct Measurement Dynamometers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7332 Indirect Force Sensors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7333 Piezoelectric Strain Sensors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7334 Resistance Strain Gauges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7335 Customized Force Sensors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 734 Acceleration Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 735 Acoustic Emission Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 736 Sensor Comparisons
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 74 Signal Processing for Sensor-Based Tool Condition Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 741 Feature Extraction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7411 Time Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7412 Frequency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7413 Statistical Processing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7414 TimendashFrequency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 742 Feature Selection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 75 Wear ModelDecision-Making for Sensor-Based Tool Condition Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 751 Trending Threshold
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 752 Neural Networks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7521 Unsupervised Networks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7522 Supervised Networks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 753 Fuzzy Logic
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 754 Other Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 76 Conclusion
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53191ch8
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Chapter 8 Fault Diagnosis of Helicopter Gearboxes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 81 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 82 Abnormality Scaling
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 83 The Structure-Based Connectionist Network
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 84 Sensor Location Selection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 841 Coverage Index
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 842 Overlap Index
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 843 Monitoring Effectiveness
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 85 A Case Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 851 Structural and Featural Influences
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 852 Evaluation of Influences
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 853 Fault Detection Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 854 Fault Diagnostic Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 8541 Faulty Subsystem Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 8542 Faulty Component Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 855 Sensor Location Evaluation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 856 Sensor Location Validation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 86 Conclusion
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 53191ch9
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Chapter 9 Vibration Suppression and Monitoring in Precision Motion Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 91 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 92 Mechanical Design to Minimize Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 921 Stability and Static Determinacy of Machine Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 922 Two-Dimensional Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 923 Three-Dimensional Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 93 Adaptive Notch Filter
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 931 Fast Fourier Transform
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 932 Simulation and Experiments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 94 Real-Time Vibration Analyzer
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 941 Learning Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 942 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 943 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 944 Experiments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 9441 Input Variables mdash the Evaluation Criteria
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 94411 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 94412 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 9442 Evaluation Rules
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 94421 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 94422 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 9443 Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 94431 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 94432 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 95 Practical Insights and Case Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 96 Conclusions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 53191ch10
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Chapter 10 Vibration and Shock Problems of Civil Engineering Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 101 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 102 Earthquake-Induced Vibration of Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1021 Seismicity and Ground Motions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1022 Influence of Local Site Conditions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1023 Response of Structures to Ground Motions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1024 Dynamic Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10241 Equations of Motion for Linear Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10242 Equations of Motion for Linear Multiple-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1025 Earthquake Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10251 Elastic Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10252 Smoothed Design Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10253 Ductility-Modified Response Spectrum Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1026 Design Philosophy and the Code Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10261 Performance-Based Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1027 Analysis Options for Earthquake Effects
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10271 Dynamic Time History Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10272 Response Spectrum Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 102721 Response Spectrum Analysis of Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 102722 Response Spectrum Analysis of Multi-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10273 Equivalent Static Analysis (Force-Based Approach)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10274 Displacement-Based Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1028 SoilndashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1029 Active and Passive Control Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 10210 Worked Examples
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 103 Dynamic Effects of Wind Loading on Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1031 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1032 Wind Speed
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1033 Design Structures for Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10331 Types of Wind Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10332 Design Criteria
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10333 Static Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1034 Along and Across-Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10341 Along-Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10342 Across-Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1035 Wind Tunnel Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1036 Comfort Criteria Human Response to Building Motion
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1037 Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1038 Comparison with Earthquake Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 104 Vibrations Due to Fluid ndashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1041 Added Mass and Inertial Coupling
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1042 Wave-Induced Vibration of Structure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 105 Blast Loading and Blast Effects on Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1051 Explosions and Blast Phenomenon
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1052 Explosive Air-Blast Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10521 Blast Wave Scaling Laws
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10522 Prediction of Blast Pressure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1053 Gas Explosion Loading and Effect of Internal Explosions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1054 Structural Response to Blast Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10541 Elastic Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10542 Elasto-Plastic Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1055 Material Behaviors at High Strain Rate
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10551 Dynamic Properties of Concrete under High Strain Rates
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10552 Dynamic Properties of Reinforcing Steel under High Strain Rates
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1056 Failure Modes of Blast-Loaded Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10561 Global Structural Behavior
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10562 Localized Structural Behavior
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10563 PressurendashImpulse ( PndashI ) Diagrams
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1057 Blast WavendashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1058 Effect of Ground Shocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10581 Loads from Air-Induced Ground Shock
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10582 Loads from Direct Ground Shock
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1059 Technical Design Manuals for Blast-Resistant Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 10510 Computer Programs for Blast and Shock Effects
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 106 Impact Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1061 Structural Impact between Two Bodies mdash Hard Impact and Soft Impact
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1062 Example mdash Aircraft Impact
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 107 Floor Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1071 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1072 Types of Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10721 Walking
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10722 Rhythmic Activities
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10723 Mechanical Equipment
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10724 Analysis Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1073 Natural Frequency of Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10731 Computing the Natural Frequency
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10732 Computing Deflection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10733 Damping
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10734 Resonance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1074 Vibration Caused by Walking
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10741 Minimum Natural Frequency
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1075 Design for Rhythmic Excitation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10751 Harmonics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10752 Minimum Natural Frequency
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1076 Example mdash Vibration Analysis of a Reinforced Concrete Floor
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 53191ch11
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Chapter 11 Seismic Base Isolation and Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 111 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1111 From Ductility Design to Base Isolation and Control Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1112 The Importance of Reducing Seismic Input and Response
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 112 Seismic Base Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1121 Historical Development of Base Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1122 Basic Principle
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1123 Issues in Seismic Base Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11231 Performance Criteria
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11232 Type of Structure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11233 Site Characteristics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11234 Retrofit Issues
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11235 Design of Building Services
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11236 Expected Life of Isolator
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1124 Seismic Isolation Devices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11241 Laminated Rubber Bearings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11242 Lead Rubber Bearing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11243 Friction-Based Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11244 Other Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1125 Design of Isolation Devices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11251 High-Damping Rubber Bearing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112511 Stability against Buckling
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112512 Stability against Roll Out
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11252 Lead Rubber Bearings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112521 Design of Lead Plug
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112522 Design of Laminated Rubber Bearing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11253 Design of Friction Pendulum System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1126 Verification of Properties of Isolation Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11261 Tests for Isolation Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 112611 System Characterization Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 112612 Prototype Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 112613 Quality Control Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11262 Uniform Building Code Recommendations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112621 Units Dependent on Loading Rates
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112622 Units Dependent on Bilateral Load
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112623 System Adequacy
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1127 Analysis of Base-Isolated Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11271 Modeling of a Superstructure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11272 Modeling of Isolation System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11273 Static Analysis Procedure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11274 Dynamic Analysis Procedure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 112741 Response Spectrum Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 112742 Time-History Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11275 Software for Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1128 Experimental Methods for Isolated Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1129 Implementation of Seismic Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11291 New Construction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112911 Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112912 Bridges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11292 Seismic Retrofit
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112921 Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112922 Bridges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11293 Other Implementations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 11210 Performance during Past Earthquakes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 112101 Performance of Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 112102 Performance of Bridges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 113 Seismic Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1131 Historical Development of Seismic Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1132 Basic Principles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11321 Passive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11322 Active Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11323 Semiactive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11324 Hybrid Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11325 Categorization of Basic Principles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1133 Important Issues in Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11331 SoilndashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11332 DevicendashStructure Interaction and Time Delay
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11333 Design Guidelines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1134 Vibration-Control Devices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11341 Passive Control Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113411 Metallic Yielding Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113412 Friction Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113413 Viscoelastic Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113414 Viscous Fluid Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113415 Tuned Mass Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11342 Active Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113421 Electromagnetic Actuator
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113422 Hydraulic Actuators
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11343 Semiactive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113431 Variable-Orifice Hydraulic Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113432 Controllable Fluid Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113433 Controllable Friction Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11344 Hybrid Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1135 Control Algorithm
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11351 Active Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11352 Semiactive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113521 Common Control Schemes for Controllable Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113522 Special Control Schemes for Controllable Damper
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1136 Experimental Performance Verification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11361 Shaking Table Tests of a Flexible Structural Model with TMD AMD and ATMD
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11362 Substructure Hybrid Test
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113621 Hybrid Tests Using Hydraulic Actuator
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113622 Hybrid Tests Using Shaking Table
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113623 Hybrid Tests Using Inertia-Force-Driven Loading System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1137 Implementations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11371 Semiactive Control of Full-Scale Structures Using Variable Joint Damper System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113711 Background of Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113712 Test System Set Up
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113713 Control Algorithm
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113714 Test Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11372 Application of Structural Control Technologies to Seismic Retrofit of a Cable-Stayed Bridge
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113721 Background of Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113722 Basic Concept of Seismic Retrofit
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113723 Modal Shape Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113724 Time-History Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113725 Soil ndash Structure Interaction Effect
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113726 Semiactive Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53191ch12
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Chapter 12 Seismic Random Vibration of Long-Span Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 121 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1211 Basic Concepts of Random Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12111 Stationary Random Process
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12112 Nonstationary Random Process
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1212 Three Methods for Structural Seismic Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12121 Response Spectrum Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12122 Time-History Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12123 Random Vibration Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 121231 Davenport Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 121232 Vanmarcke Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 12124 Comparisons of the Three Seismic-Analysis Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 122 Seismic Random-Excitation Fields
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1221 Power Spectral Density of Spatially Varying Ground Acceleration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1222 Several Coherence Models
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12221 FengndashHu Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12222 Harichandran ndashVanmarcke Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12223 LohndashYeh Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12224 OliveirandashHaondashPenzien Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12225 LucondashWong Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12226 QundashWangndashWang Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1223 Generation of Ground Acceleration Power Spectral Density Curves from Acceleration Response Spectrum Curves
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12231 Kaul Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12232 Iteration Scheme
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1224 Seismic Equations of Motion of Long-Span Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1225 Seismic Waves and Their Geometrical Expressions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 123 Pseudoexcitation Method for Structural Random Vibration Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1231 Structures Subjected to Stationary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12311 Single Stationary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12312 Multiple Stationary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1232 Structures Subjected to Nonstationary Random Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12321 Structures Subjected to Uniformly Modulated Evolutionary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 123211 Single Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 123212 Multiple Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12322 Structures Subjected to Nonuniformly Modulated Evolutionary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 123221 Single Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 123222 Multiple Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1233 Precise Integration Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12331 Precise Integration of Exponential Matrices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12332 Particular Solutions and Precise Integration Formulas for Various Forms of Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 123321 Linear Loading Form (HPD-L Form)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 123322 Sinusoidal Loading Form (HPD-S Form)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 123323 Exponentially Decaying Sinusoidal Loading Form (HPD-E Form)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 124 Long-Span Structures Subjected to Stationary Random Ground Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1241 The Solution of Equations of Motion Using the Pseudoexcitation Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1242 Numerical Comparisons with Other Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12421 Song-Hua-Jiang Suspension Bridge
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 124211 All Supports Move Uniformly
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 124212 Wave Passage Effect Is Taken into Account
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 124213 Wave-Passage Effect and Incoherence Effect Are Jointly Taken into Account
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 12422 San Joaquin Concrete Bridge
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 125 Long-Span Structures Subjected to Nonstationary Random Ground Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1251 Modulation Functions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1252 The Formulas for Nonstationary Multiexcitation Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1253 Expected Extreme Values of Nonstationary Random Processes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1254 Numerical Comparisons with the Corresponding Stationary Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 126 Conclusions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Related Titles
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                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Chapter 13 Seismic Qualification of Equipment
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 131 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 132 Distribution Qualification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1321 Drive-Signal Generation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1322 Distribution Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1323 Test Procedures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 133 Seismic Qualification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1331 Stages of Seismic Qualification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1332 Test Preliminaries
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1333 Single-Frequency Testing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1334 Multifrequency Testing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1335 Generation of RRS Specifications
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 53191ch14
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Chapter 14 Human Response to Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 141 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 142 Vibration Excitations on Humans
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1421 Excitation Characteristics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 143 Human Response to Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1431 Vibration Perception
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1432 Frequency Weighting Curve
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1433 Iso-Perception Curves
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1434 Detection Threshold Curve
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 144 Regulation of Human Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1441 Acceptable Vibration Levels in Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1442 Whole-Body Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1443 HandndashArm Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
Page 5: Vibration Monitoring, Testing, and Instrumentationpreview.kingborn.net › 646000 › d1a74678d91943e5ba1d5e... · The MEMS Handbook, Second Edition MEMS: Introduction and Fundamentals

Preface

Individual chapters authored by distinguished leaders and experienced professionals in their

respective topics this book provides for engineers technicians designers researchers educators and

students a convenient thorough up-to-date and authoritative reference source on techniques tools

and data for monitoring testing and instrumentation of mechanical vibration and shock Included

are shock and vibration methodologies particularly for civil and mechanical engineering systems

instrumentation and testing methods including sensors exciters signal acquisition conditioning

and recording and LabVIEWw tools for virtual instrumentation testing and design for seismic

vibration and related regulatory issues and human response to vibration Important information

and results are summarized as windows tables graphs and lists throughout the chapters for easy

reference and information tracking References are given at the end of each chapter for further

information and study Cross-referencing is used throughout to indicate other places in the book

where further information on a particular topic is provided

In the book equal emphasis is given to theory and practical application Analytical

formulations design approaches monitoring and testing techniques and commercial software

tools are presented and illustrated Commercial equipment computer hardware and instrumenta-

tion are described analyzed and demonstrated for field application practical implementation and

experimentation Examples and case studies are given throughout the book to illustrate the use

and application of the included information The material is presented in a format that is

convenient for easy reference and recollection

Mechanical vibration is a manifestation of the oscillatory behavior in mechanical systems as a

result of either the repetitive interchange of kinetic and potential energies among components in

the system or a forcing excitation that is oscillatory Such oscillatory responses are not limited to

purely mechanical systems and are found in electrical and fluid systems as well In purely thermal

systems however free natural oscillations are not possible and an oscillatory excitation is needed

to obtain an oscillatory response Sock is vibration caused by brief abrupt and typically high-

intensity excitations Low levels of vibration mean reduced noise and improved work environment

Consequently a considerable effort is devoted today to monitoring studying and modifying the

vibration and shock generated by machinery components machine tools transit vehicles impact

processes civil engineering structures fluid flow systems and aircraft Before designing a system

for good vibratory or shock performance it is important to understand analyze and represent the

dynamic characteristics of the system This may be accomplished through monitoring testing and

analysis of test data which is the emphasis of this book

In recent years educators researchers and practitioners have devoted considerable effort towards

studying monitoring and testing vibration and shock in a range of applications in various branches

of engineering particularly civil mechanical aeronautical and aerospace and production and

v

53191mdash1432007mdash1850mdashVELUmdash246493mdash CRC ndash pp 1ndash15

copy 2007 by Taylor amp Francis Group LLC

manufacturing Specific applications are found in machine tools transit vehicles impact processes

civil engineering structures construction machinery industrial processes product qualification and

quality control fluid flow systems ships and aircraft This book is a contribution towards these

efforts

Clarence W de SilvaEditor-in-Chief

Vancouver Canada

Prefacevi

53191mdash1432007mdash1850mdashVELUmdash246493mdash CRC ndash pp 1ndash15

copy 2007 by Taylor amp Francis Group LLC

Acknowledgments

I wish to express my gratitude to the authors of the chapters for their valuable and highly professional

contributions I am very grateful to Michael Slaughter Acquisitions Editor-Engineering CRC Press for

his enthusiasm and support throughout the project Editorial and production staff at CRC Press have

done an excellent job in getting this volume out in print Finally I wish to lovingly acknowledge the

patience and understanding of my family

vii

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copy 2007 by Taylor amp Francis Group LLC

Editor-in-Chief

Dr Clarence W de Silva PEng Fellow ASME Fellow IEEE Fellow Canadian Academy of

Engineering is Professor of Mechanical Engineering at the University of British Columbia Vancouver

Canada and has occupied the NSERC-BC Packers Research Chair in Industrial Automation since 1988

He has earned PhD degrees from the Massachusetts Institute of Technology and the University of

Cambridge England De Silva has also occupied the Mobil Endowed Chair Professorship in the

Department of Electrical and Computer Engineering at the National University of Singapore He has

served as a consultant to several companies including IBM and Westinghouse in US and has led the

development of eight industrial machines and devices He is recipient of the Henry M Paynter

Outstanding Investigator Award from the Dynamic Systems and Control Division of the American

Society of Mechanical Engineers (ASME) Killam Research Prize Lifetime Achievement Award from the

World Automation Congress Outstanding Engineering Educator Award of IEEE Canada Yasundo

Takahashi Education Award of the Dynamic Systems and Control Division of ASME IEEE Third

Millennium Medal Meritorious Achievement Award of the Association of Professional Engineers of BC

and the Outstanding Contribution Award of the Systems Man and Cybernetics Society of the Institute

of Electrical and Electronics Engineers (IEEE)

He has authored 16 technical books including Sensors and Actuators Control System Instrumentation

(Taylor amp Francis CRC Press 2007) MechatronicsmdashAn Integrated Approach (Taylor amp Francis CRC

Press Boca Raton FL 2005) Soft Computing and Intelligent Systems DesignmdashTheory Tools and

Applications (with F Karry Addison Wesley New York NY 2004) VIBRATION Fundamentals and

Practice (Taylor amp Francis CRC Press 2nd edition 2006) INTELLIGENT CONTROL Fuzzy Logic

Applications (Taylor amp Francis CRC Press 1995) Control Sensors and Actuators (Prentice Hall 1989) 14

edited volumes over 170 journal papers 200 conference papers and 12 book chapters He has served on

the editorial boards of 14 international journals in particular as the Editor-in-Chief of the International

Journal of Control and Intelligent Systems Editor-in-Chief of the International Journal of Knowledge-Based

Intelligent Engineering Systems Senior Technical Editor of Measurements and Control and Regional

Editor North America of Engineering Applications of Artificial Intelligence ndash the International Journal of

Intelligent Real-Time Automation He is a Lilly Fellow at Carnegie Mellon University NASA-ASEE Fellow

Senior Fulbright Fellow at Cambridge University ASI Fellow and a Killam Fellow Research and

development activities of Professor de Silva are primarily centered in the areas of process automation

robotics mechatronics intelligent control and sensors and actuators with cash funding of about $6

million as principal investigator

ix

53191mdash1432007mdash1850mdashVELUmdash246493mdash CRC ndash pp 1ndash15

copy 2007 by Taylor amp Francis Group LLC

Contributors

xi

Kourosh DanaiUniversity of Massachusetts

Amherst Massachusetts

Clarence W de SilvaThe University of British Columbia

Vancouver British Columbia Canada

P S HeynsUniversity of Pretoria

Pretoria South Africa

S HuangNational University of Singapore

Singapore

Hirokazu IemuraKyoto University

Kyoto Japan

Sarvesh Kumar JainMadhav Institute of Technology and

Science

Madhya Pradesh India

Christian LalanneEngineering Consultant

Jalles France

TH LeeNational University of Singapore

Singapore

YP LeowSingapore Institute of Manufacturing

Technology

Singapore

SY LimSingapore Institute of Manufacturing

Technology

Singapore

Jiaohao LinDalian University of Technology

Liaoning Peoplersquos Republic of China

W LinSingapore Institute of Manufacturing

Technology

Singapore

Chris K MechefskeQueenrsquos University

Kingston Ontario Canada

Priyan MendisUniversity of Melbourne

Melbourne Victoria Australia

Tuan NgoUniversity of Melbourne

Melbourne Victoria Australia

Mulyo Harris PradonoKyoto University

Kyoto Japan

C SchefferUniversity of Stellenbosch

Pretoria South Africa

KK TanNational University of Singapore

Singapore

KZ TangNational University of Singapore

Singapore

Yahui ZhangDalian University of Technology

Liaoning Peoplersquos Republic of China

53191mdash1432007mdash1850mdashVELUmdash246493mdash CRC ndash pp 1ndash15

copy 2007 by Taylor amp Francis Group LLC

Contents

1 Vibration Instrumentation Clarence W de Silva 1-1

11 Introduction 1-1

12 Vibration Exciters 1-3

13 Control System 1-15

14 Performance Specification 1-21

15 Motion Sensors and Transducers 1-27

16 Torque Force and Other Sensors 1-50

Appendix 1A Virtual Instrumentation for Data Acquisition Analysis

and Presentation 1-73

2 Signal Conditioning and Modification Clarence W de Silva 2-1

21 Introduction 2-2

22 Amplifiers 2-2

23 Analog Filters 2-15

24 Modulators and Demodulators 2-29

25 AnalogndashDigital Conversion 2-37

26 Bridge Circuits 2-43

27 Linearizing Devices 2-49

28 Miscellaneous Signal Modification Circuitry 2-56

29 Signal Analyzers and Display Devices 2-62

3 Vibration Testing Clarence W de Silva 3-1

31 Introduction 3-1

32 Representation of a Vibration Environment 3-3

33 Pretest Procedures 3-24

34 Testing Procedures 3-37

35 Some Practical Information 3-52

4 Experimental Modal Analysis Clarence W de Silva 4-1

41 Introduction 4-1

42 Frequency-Domain Formulation 4-2

43 Experimental Model Development 4-8

44 Curve Fitting of Transfer Functions 4-10

45 Laboratory Experiments 4-18

46 Commercial EMA Systems 4-24

xiii

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copy 2007 by Taylor amp Francis Group LLC

5 Mechanical Shock Christian Lalanne 5-1

51 Definitions 5-2

52 Description in the Time Domain 5-3

53 Shock Response Spectrum 5-4

54 Pyroshocks 5-17

55 Use of Shock Response Spectra 5-18

56 Standards 5-24

57 Damage Boundary Curve 5-26

58 Shock Machines 5-28

59 Generation of Shock Using Shakers 5-44

510 Control by a Shock Response Spectrum 5-52

511 Pyrotechnic Shock Simulation 5-58

6 Machine Condition Monitoring and Fault Diagnostics Chris K Mechefske 6-1

61 Introduction 6-2

62 Machinery Failure 6-2

63 Basic Maintenance Strategies 6-4

64 Factors Which Influence Maintenance Strategy 6-7

65 Machine Condition Monitoring 6-8

66 Transducer Selection 6-10

67 Transducer Location 6-14

68 Recording and Analysis Instrumentation 6-14

69 Display Formats and Analysis Tools 6-16

610 Fault Detection 6-21

611 Fault Diagnostics 6-25

7 Vibration-Based Tool Condition Monitoring Systems C Scheffer and PS Heyns 7-1

71 Introduction 7-1

72 Mechanics of Turning 7-2

73 Vibration Signal Recording 7-7

74 Signal Processing for Sensor-Based Tool Condition Monitoring 7-11

75 Wear ModelDecision-Making for Sensor-Based Tool Condition Monitoring 7-15

76 Conclusion 7-20

8 Fault Diagnosis of Helicopter Gearboxes Kourosh Danai 8-1

81 Introduction 8-1

82 Abnormality Scaling 8-5

83 The Structure-Based Connectionist Network 8-8

84 Sensor Location Selection 8-11

85 A Case Study 8-14

86 Conclusion 8-23

9 Vibration Suppression and Monitoring in Precision Motion Systems KK Tan

TH Lee KZ Tang S Huang SY Lim W Lin and YP Leow 9-1

91 Introduction 9-1

92 Mechanical Design to Minimize Vibration 9-2

93 Adaptive Notch Filter 9-10

94 Real-Time Vibration Analyzer 9-17

Contentsxiv

53191mdash1432007mdash1850mdashVELUmdash246493mdash CRC ndash pp 1ndash15

copy 2007 by Taylor amp Francis Group LLC

95 Practical Insights and Case Study 9-29

96 Conclusions 9-35

10 Vibration and Shock Problems of Civil Engineering Structures Priyan Mendis

and Tuan Ngo 10-1

101 Introduction 10-2

102 Earthquake-Induced Vibration of Structures 10-3

103 Dynamic Effects of Wind Loading on Structures 10-22

104 Vibrations Due to FluidndashStructure Interaction 10-33

105 Blast Loading and Blast Effects on Structures 10-34

106 Impact Loading 10-47

107 Floor Vibration 10-51

11 Seismic Base Isolation and Vibration Control Hirokazu Iemura Sarvesh Kumar Jain

and Mulyo Harris Pradono 11-1

111 Introduction 11-1

112 Seismic Base Isolation 11-4

113 Seismic Vibration Control 11-33

12 Seismic Random Vibration of Long-Span Structures Jiahao Lin and Yahui Zhang 12-1

121 Introduction 12-2

122 Seismic Random-Excitation Fields 12-11

123 Pseudoexcitation Method for Structural Random Vibration Analysis 12-16

124 Long-Span Structures Subjected to Stationary Random Ground Excitations 12-27

125 Long-Span Structures Subjected to Nonstationary Random Ground Excitations 12-34

126 Conclusions 12-39

13 Seismic Qualification of Equipment Clarence W de Silva 13-1

131 Introduction 13-1

132 Distribution Qualification 13-1

133 Seismic Qualification 13-6

14 Human Response to Vibration Clarence W de Silva 14-1

141 Introduction 14-1

142 Vibration Excitations on Humans 14-2

143 Human Response to Vibration 14-3

144 Regulation of Human Vibration 14-6

Contents xv

53191mdash1432007mdash1850mdashVELUmdash246493mdash CRC ndash pp 1ndash15

copy 2007 by Taylor amp Francis Group LLC

1Vibration

Instrumentation

Clarence W de SilvaThe University of British Columbia

11 Introduction 1-1

12 Vibration Exciters 1-3Shaker Selection dagger Dynamics of Electromagnetic Shakers

13 Control System 1-15Components of a Shaker Controller dagger Signal-Generating

Equipment

14 Performance Specification 1-21Parameters for Performance Specification dagger Linearity dagger

Instrument Ratings dagger Accuracy and Precision

15 Motion Sensors and Transducers 1-27Potentiometer dagger Variable-Inductance Transducers dagger

Mutual-Induction Proximity Sensor dagger Selfinduction

Transducers dagger Permanent-Magnet Transducers dagger

Alternating Current Permanent-Magnet Tachometer dagger

Alternating Current Induction Tachometer dagger Eddy Current

Transducers dagger Variable-Capacitance Transducers dagger

Piezoelectric Transducers

16 Torque Force and Other Sensors 1-50Strain Gage Sensors dagger Miscellaneous Sensors

Appendix 1A Virtual Instrumentation for DataAcquisition Analysis and Presentation 1-73

Summary

Devices useful in instrumenting a mechanical vibrating system are presented in this chapter Shakers whichgenerate vibration excitations are discussed and compared A variety of sensors including motion sensorsproximity sensors forcetorque sensors and other miscellaneous sensors are considered Performance specificationin the time domain and the frequency domain is addressed Rating parameters of instruments are given

11 Introduction

Measurement and associated experimental techniques play a significant role in the practice of vibration

Academic exposure to vibration instrumentation usually arises in laboratories in the context of learning

training and research In vibration practice perhaps the most important task of instrumentation is the

measurement or sensing of vibration Vibration sensing is useful in the following applications

1 Design and development of a product

2 Testing (screening) of a finished product for quality assurance

3 Qualification of a good-quality product to determine its suitability for a specific application

1-1

53191mdash522007mdash1201mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

4 Mechanical aging of a product prior to carrying out a test program

5 Exploratory testing of a product to determine its dynamic characteristics such as resonances

mode shapes and even a complete dynamic model

6 Vibration monitoring for performance evaluation

7 Control and suppression of vibration

Figure 11 indicates a procedure typical of experimental vibration highlighting the essential

instrumentation Vibrations are generated in a device the test object in response to some excitation In

some experimental procedures primarily in vibration testing (see Figure 11) the excitation signal has

to be generated in a signal generator in accordance with some requirement (specification) and applied to

the object through an exciter after amplification and conditioning In some other situations primarily in

performance monitoring and vibration control the excitations are generated as an integral part of the

operating environment of the vibrating object and may originate either within the object (eg engine

excitations in an automobile) or in the environment with which the object interacts during operation

(eg road disturbances on an automobile) Sensors are needed to measure vibrations in the test object In

particular a control sensor is used to check whether the specified excitation is applied to the object

and one or more response sensors may be used to measure the resulting vibrations at key locations of

the object

The sensor signals have to be properly conditioned for example by filtering and amplification and

modified for example through modulation demodulation and analog-to-digital conversion prior to

recording analyzing and display The purpose of the controller is to guarantee that the excitation is

correctly applied to the test object If the signal from the control sensor deviates from the required

excitation the controller modifies the signal to the exciter so as to reduce this deviation Furthermore the

controller will stabilize or limit (compress) the vibrations in the object It follows that instruments in

experimental vibration may be generally classified into the following categories

1 Signal-generating devices

2 Vibration exciters

3 Sensors and transducers

4 Signal conditioningmodifying devices

5 Signal analysis devices

6 Control devices

7 Vibration recording and display devices

AnalogDigital

Interface

DigitalSignal

RecorderAnalyzerDisplay

FilterAmplifier

FilterAmplifier

SignalGenerator

and ExciterController

Reference (Required)Signal (Specification)

PowerAmplifier

MountingFixtures

TestObject

ResponseSensor

ControlSensor

Exciter

SwivelBase

FIGURE 11 Typical instrumentation in experimental vibration

Vibration Monitoring Testing and Instrumentation1-2

53191mdash522007mdash1201mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

Note that one instrument may perform the tasks

of more than one category listed here Also more

than one instrument may be needed to carry out

tasks in a single category In the following sections

we will provide some examples of the types of

vibration instrumentation giving characteristics

operating principles and important practical

considerations Also we will describe several

experiments which can be found in a typical

vibration laboratory

An experimental vibration system generally

consists of four main subsystems

1 Test object

2 Excitation system

3 Control system

4 Signal acquisition and modification system

These are schematically shown in Figure 12 Note that various components shown in Figure 11 may

be incorporated into one of these subsystems In particular component matching hardware and object

mounting fixtures may be considered interfacing devices that are introduced through the interaction

between the main subsystems as shown in Figure 12 Some important issues of vibration testing and

instrumentation are summarized in Box 11

12 Vibration Exciters

Vibration experimentation may require an external exciter to generate the necessary vibration This is the

case in controlled experiments such as product testing where a specified level of vibration is applied to the

test object and the resulting response is monitored A variety of vibration exciters are available with

different capabilities and principles of operation

Three basic types of vibration exciters (shakers) are widely used hydraulic shakers inertial shakers

and electromagnetic shakers The operation-capability ranges of typical exciters in these three categories

are summarized in Table 11 Stroke or maximum displacement is the largest displacement the exciter

is capable of imparting onto a test object whose weight is assumed to be within its design load limit

Maximum velocity and acceleration are similarly defined Maximum force is the largest force that could

be applied by the shaker to a test object of acceptable weight (one within the design load) The values

given in Table 11 should be interpreted with caution Maximum displacement is achieved only at very

low frequencies The achievement of maximum velocity corresponds to intermediate frequencies in the

operating frequency range of the shaker Maximum acceleration and force ratings are usually achieved at

high frequencies It is not feasible for example to operate a vibration exciter at its maximum

displacement and its maximum acceleration simultaneously

Consider a loaded exciter that is executing harmonic motion Its displacement is given by

x frac14 s sin vt eth11THORN

in which s is the displacement amplitude (or stroke) Corresponding velocity and acceleration are

_x frac14 sv cos vt eth12THORN

eurox frac14 2sv2sin vt eth13THORN

SignalModification

System

TestObject

ControlSystem

VibrationExciter (Shaker)

System

FIGURE 12 Interactions between major subsystems of

an experimental vibration system

Vibration Instrumentation 1-3

53191mdash522007mdash1201mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

If the velocity amplitude is denoted by v and the acceleration amplitude by a it follows from Equation

12 and Equation 13 thatv frac14 vs eth14THORN

and

a frac14 vv eth15THORN

Box 11

VIBRATION INSTRUMENTATION

Vibration Testing Applications for Products

Design and Development Production Screening and Quality Assessment Utilization and Qualification for Special Applications

Testing Instrumentation

Exciter (excites the test object) Controller (controls the exciter for accurate excitation) Sensors and Transducers (measure excitations and responses and provide excitation error

signals to controller) Signal Conditioning (converts signals to appropriate form) Recording and Display (perform processing storage and documentation)

Exciters

Shakers

1 Electrodynamic (high bandwidth moderate power complex and multifrequency

excitations)

2 Hydraulic (moderate to high bandwidth high power complex and multifrequency

excitations)

3 Inertial (low bandwidth low power single-frequency harmonic excitations)

TransientInitial Condition

1 Hammers (impulsive bump tests)

2 Cable Release (step excitations)

3 Drop (impulsive)

Signal Conditioning

Filters Amplifiers Amplifiers ModulatorsDemodulators ADCDAC

Sensors

Motion (displacement velocity acceleration) Force (strain torque)

Vibration Monitoring Testing and Instrumentation1-4

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copy 2007 by Taylor amp Francis Group LLC

TABLE 11 Typical Operation-Capability Ranges for Various Shaker Types

Shaker Type Typical Operational Capabilities

Frequency Maximum Displacement

(Stroke)

Maximum

Velocity

Maximum

Acceleration

Maximum

Force

Excitation

Waveform

Hydraulic

(electrohydraulic)

Low

(01ndash500 Hz)

High (20 in 50 cm) Intermediate

(50 insec

125 cmsec)

Intermediate

(20 g)

High (100000 lbf

450000 N)

Average flexibility (simple

to complex and random)

Inertial

(counter-rotating mass)

Intermediate

(2ndash50 Hz)

Low (1 in 25 cm) Intermediate

(50 insec

125 cmsec)

Intermediate

(20 g)

Intermediate

(1000 lbf 4500 N)

Sinusoidal only

Electromagnetic

(electrodynamic)

High

(2ndash10000 Hz)

Low (1 in 25 cm) Intermediate

(50 insec

125 cmsec)

High (100 g) Low to intermediate

(450 lbf 2000 N)

High flexibility and accuracy

(simple to complex and

random)

VibrationInstru

mentation

1-5

53191mdash522007mdash

1201mdashSENTHILKUMARmdash246494mdash

CRCndashpp1ndash112

copy 2007 by Taylor amp Francis Group LLC

An idealized performance curve of a shaker

has a constant displacementndashamplitude region a

constant velocityndashamplitude region and a con-

stant accelerationndashamplitude region for low

intermediate and high frequencies respectively

in the operating frequency range Such an ideal

performance curve is shown in Figure 13(a) on a

frequencyndashvelocity plane Logarithmic axes are

used In practice typical shaker performance

curves would be fairly smooth yet nonlinear

curves similar to those shown in Figure 13(b)

As the mass increases the performance curve

compresses Note that the acceleration limit of a

shaker depends on the mass of the test object

(load) Full load corresponds to the heaviest object

that could be tested The ldquono loadrdquo condition

corresponds to a shaker without a test object To

standardize the performance curves they are

usually defined at the rated load of the shaker A

performance curve in the frequencyndashvelocity

plane may be converted to a curve in the

frequencyndashacceleration plane simply by increasing

the slope of the curve by a unit magnitude (ie

20 dbdecade)

Several general observations can be made from

Equation 14 and Equation 15 In the constant-

peak displacement region of the performance

curve the peak velocity increases proportionally

with the excitation frequency and the peak

acceleration increases with the square of the excitation frequency In the constant-peak velocity region

the peak displacement varies inversely with the excitation frequency and the peak acceleration increases

proportionately In the constant-peak acceleration region the peak displacement varies inversely with the

square of the excitation frequency and the peak velocity varies inversely with the excitation frequency

This further explains why rated stroke maximum velocity and maximum acceleration values are not

simultaneously realized

121 Shaker Selection

Vibration testing is accomplished by applying a specified excitation to the test package using a shaker

apparatus and monitoring the response of the test object Test excitation may be represented by its

response spectrum The test requires that the response spectrum of the actual excitation known as the

test response spectrum (TRS) envelops the response spectrum specified for the particular test known as

the required response spectrum (RRS)

A major step in the planning of any vibration testing program is the selection of a proper shaker

(exciter) system for a given test package The three specifications that are of primary importance in

selecting a shaker are the force rating the power rating and the stroke (maximum displacement) rating

Force and power ratings are particularly useful in moderate to high frequency excitations and the stroke

rating is the determining factor for low frequency excitations In this section a procedure is given to

determine conservative estimates for these parameters in a specified test for a given test package

Frequency domain considerations are used here

Stroke

Limit M

ax

Acceleration

MaxVelocity

Peak

Vel

ocity

(cm

s)

01 1 10 100

FullLoad

NoLoad

Frequency (Hz)(a)

Peak

Vel

ocity

(cm

s)

100

10

1

100

10

1

01 1 10 100

FullLoad

NoLoad

Frequency (Hz)(b)

FIGURE 13 Performance curve of a vibration exciter

in the frequencyndashvelocity plane (log) (a) ideal (b)

typical

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copy 2007 by Taylor amp Francis Group LLC

1211 Force Rating

In the frequency domain the (complex) force at the exciter (shaker) head is given by

F frac14 mHethvTHORNasethvTHORN eth16THORNin which v is the excitation frequency variable m is the total mass of the test package including

mounting fixture and attachments asethvTHORN is the Fourier spectrum of the support-location (exciter head)

acceleration and H(v) is frequency response function that takes into account the flexibility and

damping effects (dynamics) of the test package apart from its inertia In the simplified case where the

test package can be represented by a simple oscillator of natural frequency vn and damping ratio by zt

this function becomes

HethvTHORN frac14 1thorn 2jztv=vn=12 ethv=vnTHORN2 thorn 2jztv=vn eth17THORNin which j frac14 ffiffiffiffi

21p

This approximation is adequate for most practical purposes The static weight of the

test object is not included in Equation 16 Most heavy-duty shakers which are typically hydraulic

have static load support systems such as pneumatic cushion arrangements that can exactly balance the

dead load The exciter provides only the dynamic force In cases where shaker directly supports the

gravity load in the vertical test configuration Equation 16 should be modified by adding a term to

represent this weight

A common practice in vibration test applications is to specify the excitation signal by its response

spectrum This is simply the peak response of a simple oscillator expressed as a function of its natural

frequency when its support location is excited by the specified signal Clearly the damping of the simple

oscillator is an added parameter in a response spectrum specification Typical damping ratios ethzrTHORN used inresponse spectra specifications are less than 01 (or 10) It follows that an approximate relationship

between the Fourier spectrum of the support acceleration and its response spectrum is

as frac14 2jzrarethvTHORN eth18THORNThe magnitude larethvTHORNl is the response spectrumEquation 18 substituted into Equation 16 gives

F frac14 mHethvTHORN2jzrarethvTHORN eth19THORNIn view of Equation 17 for test packages having low damping the peak value of H(v) is

approximately 1=eth2jztTHORN this should be used in computing the force rating if the test package has a

resonance within the frequency range of testing On the other hand if the test package is assumed to be

rigid then HethvTHORN oslash 1 A conservative estimate for the force rating is

Fmax frac14 methzr=ztTHORNlarethvTHORNlmax eth110THORNIt should be noted that larethvTHORNlmax is the peak value of the specified (required) response spectrum (RRS)

for acceleration

1212 Power Rating

The exciter head does not develop its maximum force when driven at maximum velocity Output power

is determined by using

p frac14 Refrac12FvsethvTHORN eth111THORNin which vsethvTHORN is the Fourier spectrum of the exciter velocity and Re [ ] denotes the real part of a complex

function Note that as frac14 jvvs Substituting Equation 16 and Equation 18 into Equation 111 gives

p frac14 eth4mz2r =vTHORNRefrac12jHethvTHORNa2r ethvTHORN eth112THORNIt follows that a conservative estimate for the power rating is

pmax frac14 2methz2r =ztTHORNfrac12larethvTHORNl2=v max eth113THORN

Vibration Instrumentation 1-7

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copy 2007 by Taylor amp Francis Group LLC

Representative segments of typical acceleration RRS curves have slope n as given by

a frac14 k1vn eth114THORN

It should be clear from Equation 113 that the maximum output power is given by

pmax frac14 k2v2n21 eth115THORN

This is an increasing function for n 1=2 and a decreasing function for n 1=2 It follows that the power

rating corresponds to the highest point of contact between the acceleration RRS curve and a line of slope

equal to 12 A similar relationship may be derived if velocity RRS curves (having slopes n2 1) are used

1213 Stroke Rating

From Equation 18 it should be clear that the Fourier spectrum xs of the exciter displacement time

history can be expressed as

xs frac14 2zrarethvTHORN=jv2 eth116THORNAn estimate for stroke rating is

xmax frac14 2zrfrac12larethvTHORNl=v2 max eth117THORNThis is of the form

xmax frac14 kvn22 eth118THORNIt follows that the stroke rating corresponds to the highest point of contact between the acceleration

RRS curve and a line of slope equal to two

Example 11

A test package of overall mass 100 kg is to be

subjected to dynamic excitation represented by the

acceleration RRS (at 5 damping) as shown in

Figure 14 The estimated damping of the test

package is 7 The test package is known to have a

resonance within the frequency range of the

specified test Determine the exciter specifications

for the test

Solution

From the development presented in the previous

section it is clear that the point F (or P) in

Figure 14 corresponds to the force and output

power ratings and the point S corresponds to

the stroke rating The co-ordinates of these

critical points are F P frac14 eth42 Hz 40 gTHORN and S frac14 eth08 Hz 075 gTHORN Equation 110 gives the force

rating as

Fmax frac14 100 pound eth005=007THORN pound 40 pound 981 N frac14 2803 N

Equation 113 gives the power rating as

pmax frac14 2 pound 100 pound eth0052=007THORN pound frac12eth40 pound 981THORN2=42 pound 2p watts frac14 417 W

Equation 117 gives the stroke rating as

xmax frac14 2 pound 005 pound frac12eth075 pound 98THORN=eth08 pound 2pTHORN2 m frac14 3 cm

Acc

eler

atio

n(g

)

Con

stan

t Dis

plac

emen

t

Constant Velo

city

Frequency (Hz)

S

FP

0101

10 10 100

10

10

FIGURE 14 Test excitation specified by an accelera-

tion RRS (5 damping)

Vibration Monitoring Testing and Instrumentation1-8

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copy 2007 by Taylor amp Francis Group LLC

1214 Hydraulic Shakers

A typical hydraulic shaker consists of a piston-cylinder arrangement (also called a ram) a servo-valve a

fluid pump and a driving electric motor Hydraulic fluid (oil) is pressurized (typical operating pressure

4000 psi) and pumped into the cylinder through a servo-valve by means of a pump that is driven by an

electric motor (typical power 150 hp) The flow (typical rate 100 galmin) that enters the cylinder is

controlled (modulated) by the servo-valve which in effect controls the resulting piston (ram) motion

A typical servo-valve consists of a two-stage spool valve which provides a pressure difference and a

controlled (modulated) flow to the piston which sets it in motion

The servo-valve itself is moved by means of a linear torque motor which is driven by the excitation-

input signal (electrical) A primary function of the servo-valve is to provide a stabilizing feedback to the

ram In this respect the servo-valve complements the main control system of the test setup The ram is

coupled to the shaker table by means of a link with some flexibility The cylinder frame is mounted on the

support foundation with swivel joints This allows for some angular and lateral misalignment which

might be caused primarily by test-object dynamics as the table moves

Two-degree-of-freedom (Two-DoF) testing requires two independent sets of actuators and three-DoF

testing requires three independent actuator sets Each independent actuator set can consist of several

actuators operated in parallel using the same pump and the same excitation-input signal to the torque

motors

If the test table is directly supported on the vertical actuators they must withstand the total dead

weight (ie the weight of the test table the test object the mounting fixtures and the instrumentation)

This is requirement is usually prevented by providing a pressurized air cushion in the gap between the

test table and the foundation walls Air should be pressurized so as to balance the total dead weight

exactly (typical required gage pressure 3 psi)

Figure 15(a) shows the basic components of a typical hydraulic shaker The corresponding

operational block diagram is shown in Figure 15(b) It is desirable to locate the actuators in a pit in the

test laboratory so that the test tabletop is flushed with the test laboratory floor under no-load conditions

This minimizes the effort required to place the test object on the test table Otherwise the test object has

to be lifted onto the test table with a forklift Also installation of an aircushion to support the system

dead weight is difficult under these circumstances of elevated mounting

Hydraulic actuators are most suitable for heavy load testing and are widely used in industrial and civil

engineering applications They canbeoperated at very low frequencies (almost direct current [DC]) aswell

as at intermediate frequencies (see Table 11) Large displacements (stroke) are possible at low frequencies

Hydraulic shakers have the advantage of providing high flexibility of operation during the test their

capabilities include variable-force and constant-force testing and wide-band random-input testing The

velocity and acceleration capabilities of hydraulic shakers are moderate Although any general excitation-

input motion (for example sine wave sine beat wide-band random) can be used in hydraulic shakers

faithful reproduction of these signals is virtually impossible at high frequencies because of distortion and

higher-order harmonics introduced by the high noise levels that are common in hydraulic systems This

is only a minor drawback in heavy-duty intermediate-frequency applications Dynamic interactions are

reduced through feedback control

1215 Inertial Shakers

In inertial shakers or ldquomechanical excitersrdquo the force that causes the shaker-table motion is generated by

inertia forces (accelerating masses) Counter-rotating-mass inertial shakers are typical in this category

To understand their principle of operation consider two equal masses rotating in opposite directions at

the same angular speed v and in the same circle of radius r (see Figure 16) This produces a resultant

force equal to 2mv2r cos vt in a fixed direction (the direction of symmetry of the two rotating arms)

Consequently a sinusoidal force with a frequency of v and an amplitude proportional to v2 is generated

This reaction force is applied to the shaker table

Figure 17 shows a sketch of a typical counter-rotating-mass inertial shaker It consists of two identical

rods rotating at the same speed in opposite directions Each rod has a series of slots in which to

Vibration Instrumentation 1-9

53191mdash522007mdash1201mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

place weights In this manner the magnitude of

the eccentric mass can be varied to achieve various

force capabilities The rods are driven by a

variable-speed electric motor through a gear

mechanism that usually provides several speed

ratios A speed ratio is selected depending on the

required test-frequency range The whole system is

symmetrically supported on a carriage that is

directly connected to the test table The test object

is mounted on the test table The preferred

mounting configuration is horizontal so that the

excitation force is applied to the test object in a

horizontal direction In this configuration there

are no variable gravity moments (weight pounddistance to center of gravity) acting on the drive

mechanism Figure 17 shows the vertical con-

figuration In dynamic testing of large structures

the carriage can be mounted directly on the

structure at a location where the excitation force

should be applied By incorporating two pairs of

counter-rotating masses it is possible to generate

test moments as well as test forces

FIGURE 15 A typical hydraulic shaker arrangement (a) schematic diagram (b) operational block diagram

m m

2mw2r cos wt

wtw w

wt

FIGURE 16 Principle of operation of a counter-

rotating-mass inertial shaker

Vibration Monitoring Testing and Instrumentation1-10

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copy 2007 by Taylor amp Francis Group LLC

Reaction-type shakers driven by inertia are widely used for the prototype testing of civil engineering

structures Their first application dates back to 1935 Inertial shakers are capable of producing

intermediate excitation forces The force generated is limited by the strength of the carriage frame The

frequency range of operation and the maximum velocity and acceleration capabilities are also

intermediate for inertial shakers whereas the maximum displacement capability is typically low A major

limitation of inertial shakers is that their excitation force is exclusively sinusoidal and that the force

amplitude is directly proportional to the square of the excitation frequency As a result complex and

random excitation testing constant-force testing (for example transmissibility tests and constant-force

sine-sweep tests) and flexibility to vary the force amplitude or the displacement amplitude during a test

are not generally feasible with this type of shakers Excitation frequency and amplitude can be varied

during testing however by incorporating a variable-speed drive for the motor The sinusoidal excitation

generated by inertial shakers is virtually undistorted which gives them an advantage over the other types

of shakers when used in sine-dwell and sine-sweep tests Small portable shakers with low-force capability

are available for use in on-site testing

1216 Electromagnetic Shakers

In electromagnetic shakers or ldquoelectrodynamic excitersrdquo the motion is generated using the principle of

operation of an electric motor Specifically the excitation force is produced when a variable excitation

signal (electrical) is passed through a moving coil placed in a magnetic field

The components of a commercial electromagnetic shaker are shown in Figure 18 A steady magnetic

field is generated by a stationary electromagnet that consists of field coils wound on a ferromagnetic base

that is rigidly attached to a protective shell structure The shaker head has a coil wound around it When

the excitation electrical signal is passed through this drive coil the shaker head which is supported on

flexure mounts will be set in motion The shaker head consists of the test table on which the test object

is mounted Shakers with interchangeable heads are available The choice of appropriate shaker head is

based on the geometry and mounting features of the test object The shaker head can be turned to

different angles by means of a swivel joint In this manner different directions of excitation (in biaxial

and triaxial testing) can be obtained

FIGURE 17 Sketch of a counter-rotating-mass inertial shaker

Vibration Instrumentation 1-11

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copy 2007 by Taylor amp Francis Group LLC

122 Dynamics of Electromagnetic Shakers

Consider a single axis electromagnetic shaker (Figure 18) with a test object having a single natural

frequency of importance within the test frequency range The dynamic interactions between the shaker

and the test object give rise to two significant natural frequencies (and correspondingly two significant

resonances) These appear as peaks in the frequency response curve of the test setup Furthermore the

natural frequency (resonance) of the test package alone causes a ldquotroughrdquo or depression (antiresonance)

in the frequency response curve of the overall test setup To explain this characteristic consider the

dynamic model shown in Figure 19 The following mechanical parameters are defined for

Figure 19(a) m k and b are the mass stiffness and equivalent viscous damping constant respectively

of the test package and me ke and be are the corresponding parameters of the exciter (shaker) Also in

the equivalent electrical circuit of the shaker head as shown in Figure 19(b) the following electrical

parameters are defined Re and Le are the resistance and (leakage) inductance and kb is the back

electromotive force (back emf) of the linear motor Assuming that the gravitational forces are supported

FIGURE 18 Schematic sectional view of a typical electromagnetic shaker manufactured by Bruel and Kjaer

Denmark

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by the static deflections of the flexible elements and that the displacements are measured from the static

equilibrium position we have the following system equations

Test object meuroy frac14 2kethy2 yeTHORN2 beth_y2 _yeTHORN eth119THORNShaker head me euroye frac14 fe thorn kethy2 yeTHORN thorn beth_y2 _yeTHORN2 key 2 be _ye eth120THORN

Electrical Lediedt

thorn Reie thorn kb _ye frac14 vethtTHORN eth121THORN

The electromagnetic force fe generated in the shaker head is a result of the interaction of the magnetic

field generated by the current ie with coil of the moving shaker head and the constant magnetic field

(stator) in which the head coil is located Here we have

fe frac14 kbie eth122THORNNote that v(t) is the voltage signal that is applied by the amplifier to the shaker coil ye is the displacement

of the shaker head and y is the displacement response of the test package

It is assumed that kb has consistent electrical and mechanical units (Vmsec and NA) Usually

the electrical time constant of the shaker is quite small compared with the primarily mechanical

time constants of the shaker and the test package In such cases the Ledie=dt term in Equation 121 may

be neglected Consequently the equations from Equation 119 through Equation 122 may be

expressed in the Laplace (frequency) domain with the Laplace variable s taking the place of the derivative

d=dt as

ethms2 thorn bsthorn kTHORNy frac14 ethbsthorn kTHORNye eth123THORN

FIGURE 19 Dynamic models of an electromagnetic shaker and a flexible test package (a) mechanical model

(b) electrical model

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frac12mes2 thorn ethbthorn beTHORNsthorn ethkthorn keTHORN ye frac14 ethbsthorn kTHORNy thorn kb

Rev2

k2bs

Reye eth124THORN

It follows that the transfer function of the shaker head motion with respect to the excitation voltage is

given by

yevfrac14 kb

Re

DethsTHORNDdethsTHORN eth125THORN

where DethsTHORN is the characteristic function of the primary dynamics of the test object

DethsTHORN frac14 ms2 thorn bsthorn k eth126THORN

and DdethsTHORN is the characteristic function of the primary dynamic interactions between the shaker and thetest object

DcethsTHORN frac14 mmes4 thorn frac12methbe thorn bthorn boTHORN thornmeb s

3 thorn frac12methke thorn kTHORN thornmekthorn bethbe thorn boTHORN s2thorn frac12bke thorn ethbe thorn boTHORNk sthorn kke

eth127THORN

where

bo frac14 k2bRe

eth128THORN

It is clear that under low damping conditions DdethsTHORN will produce two resonances as it is fourth order in sand similarly DethsTHORN will produce one antiresonance (trough) corresponding to the resonance of the testobject Note that in the frequency domain s frac14 jv and hence the frequency response function given by

Equation 125 is in fact

yevfrac14 kb

Rb

DethjvTHORNDdethjvTHORN eth129THORN

The magnitude of this frequency response function for a typical test system is sketched in Figure 110

Note that this curve is for the ldquoopen-looprdquo case where there is no feedback from the shaker controller

In practice the shaker controller will be able

to compensate for the resonances and anti-

resonances to some degree depending on its

effectiveness

The main advantages of electromagnetic

shakers are their high frequency range of

operation their high degree of operating flexi-

bility and the high level of accuracy of the

generated shaker motion Faithful reproduction

of complex excitations is possible because of the

advanced electronics and control systems used in

this type of shakers Electromagnetic shakers are

not suitable for heavy-duty applications (large test

objects) however High test-input accelerations

are possible at high frequencies when electromag-

netic shakers are used but their displacement and

velocity capabilities are limited to low or

intermediate values (see Table 11)

100

10

1 10 100Excitation Frequency (Hz)

Antiresonance

Resonance

Shak

erD

ispl

acem

entM

agni

tude

Resonance

1000

FIGURE 110 Frequency response curve of a typical

electromagnetic shaker with a test object

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1221 Transient Exciters

Other varieties of exciters are commonly used in

transient-type vibration testing In these tests

either an impulsive force or an initial excitation is

applied to the test object and the resulting

response is monitored The excitations and the

responses are ldquotransientrdquo in this case Hammer

test drop tests and pluck tests fall into this

category For example a hammer test may be

conducted by hitting the object with an instru-

mented hammer and then measuring the response

of the object The hammer has a force sensor at its

tip as sketched in Figure 111 A piezoelectric or

strain-gage type force sensor may be used More

sophisticated hammers have impedance heads in

place of force sensors An impedance head

measures force and acceleration simultaneously

The results of a hammer test will depend on many

factors for example the dynamics of the hammer

body how firmly the hammer is held during the

impact how quickly the impact is applied and

whether there are multiple impacts

13 Control System

The two primary functions of the shaker control system in vibration testing are (1) to guarantee that the

specified excitation is applied to the test object and (2) to ensure that the dynamic stability (motion

constraints) of the test setup is preserved An operational block diagram illustrating these control

functions is given in Figure 112 The reference input to the control system represents the desired

excitation force that should be applied to the test object In the absence of any control however the force

reaching the test object will be distorted primarily because of (1) dynamic interactions and

nonlinearities of the shaker the test table the mounting fixtures the auxiliary instruments and the test

object itself (2) noise and errors in the signal generator amplifiers filters and other equipment and (3)

external loads and disturbances acting on the test object and other components (for example external

restraints aerodynamic forces friction) To compensate for these distorting factors response

measurements (displacements velocities acceleration and so on) are made at various locations in the

test setup and are used to control the system dynamics In particular the responses of the shaker the test

table and the test object are measured These responses are used to compare the actual excitation felt by

FIGURE 111 An instrumented hammer used in bump

tests or hammer tests

ExcitationInput

(Reference)

Feedback Paths

DriveSignal

ShakerResponse

TestTable

TestObject

Test ObjectResponse

Test TableResponseExciter

(Shaker)(Ram)

Controllerand

Amplifier

FIGURE 112 Operational block diagram illustrating a general shaker control system

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the test object at the shaker interface with the desired (specified) input The drive signal to the shaker is

modified depending on the error that is present

Two types of control are commonly employed in shaker apparatus simple manual control and

complex automatic control Manual control normally consists of simple open-loop trial-and-error

methods of manual adjustments (or calibration) of the control equipment to obtain a desired dynamic

response The actual response is usually monitored (on an oscilloscope or frequency analyzer screen for

example) during manual-control operations The pretest adjustments in manual control can be very

time-consuming as a result the test object might be subjected to overtesting which could produce

cumulative damage is undesirable and could defeat the test purpose Furthermore the calibration

procedure for the experimental setup must be repeated for each new test object

The disadvantages ofmanual control suggest that automatic control is desirable in complex test schemes

in which high accuracy of testing is desired The first step of automatic control involves automatic

measurement of the system response using control sensors and transducers The measurement is then fed

back into the control system which instantaneously determines the best drive signal to actuate the shaker

in order to get the desired excitation This may be done by either analog or digital methods

Primitive control systems require an accurate mathematical description of the test object This

dependency of the control system on the knowledge of test-object dynamics is clearly undesirable

Performance of a good control system should not be considerably affected by the dynamic interactions

and nonlinearities of the test object or by the nature of the excitation Proper selection of feedback signals

and control-system components can reduce such effects and will make the system robust

In the response-spectrum method of vibration testing it is customary to use displacement control at

low frequencies velocity control at intermediate frequency and acceleration control at high frequencies

This necessitates feedback of displacement velocity and acceleration responses Generally however the

most important feedback is the velocity feedback In sine-sweep tests the shaker velocity must change

steadily over the frequency band of interest In particular the velocity control must be precise near the

resonances of the test object Velocity (speed) feedback has a stabilizing effect on the dynamics which is

desirable This effect is particularly useful in ensuring stability in motion when testing is done near

resonances of lightly damped test objects On the contrary displacement (position) feedback can have a

destabilizing effect on some systems particularly when high feedback gains are used

The controller usually consists of various instruments equipment and computation hardware and

software Often the functions of the data-acquisition and processing system overlap with those of the

controller to some extent As an example consider the digital-controller of vibration testing apparatus

First the responses are measured through sensors (and transducers) filtered and amplified

(conditioned) These data channels may be passed through a multiplexer whose purpose is to select

one data channel at a time for processing Most modern data acquisition hardware does not need a

separate multiplexer to handle multiple signals The analog data are converted into digital data using

analog-to-digital converters (ADCs) The resulting sampled data are stored on a disk or as a block data in

the computer memory The reference input signal (typically a signal recorded on an FM tape) is also

sampled (if it is not already in the digital form) using an ADC and fed into the computer Digital

processing is done on the reference signal and the response data with the objective of computing the

command signal to drive the shaker The digital command signal is converted into an analog signal using

a digital-to-analog converter (DAC) and amplified (conditioned) before it is used to drive the exciter

The nature of the control components depends to a large extent on the nature and objectives of the

particular test to be conducted Some of the basic components in a shaker controller are described in

the following subsections

131 Components of a Shaker Controller

1311 Compressor

A compressor circuit is incorporated in automatic excitation control devices to control the excitation-

input level automatically The level of control depends on the feedback signal from a control sensor and

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the specified (reference) excitation signal Usually the compressor circuit is included in the excitation-

signal generator (for example in a sine generator) The control by this means may be done on the basis of

a single-frequency component (eg the fundamental frequency)

1312 Equalizer (Spectrum Shaper)

Random-signal equalizers are used to shape the spectrum of a random signal in a desired manner In

essence and equalizer consists of a bank of narrow-band filters (for example 80 filters) in parallel over

the operating frequency range By passing the signal through each filter the spectral density (or the mean

square value) of the signal in that narrow frequency band (for example each one-third-octave band) is

determined This is compared with the desired spectral level and automatic adjustment is made in that

filter in case there is an error In some systems response-spectrum analysis is made in place of power

spectral density analysis In that case the equalizer consists of a bank of simple oscillators whose

resonant frequencies are distributed over the operating frequency range of the equalizer The feedback

signal is passed through each oscillator and the peak value of its output is determined This value is

compared with the desired response spectrum value at that frequency If there is an error automatic gain

adjustment is made in the appropriate excitation signal components

Random-noise equalizers are used in conjunction with random signal generators They receive

feedback signals from the control sensors In some digital control systems there are algorithms (software)

that are used to iteratively converge the spectrum of the excitation signal felt by the test object into the

desired spectrum

1313 Tracking Filter

Many vibration tests are based on single-frequency excitations In such cases the control functions

should be performed on the basis of the amplitudes of the fundamental-frequency component of the

signal A tracking filter is simply a frequency-tuned band-pass filter It automatically tunes the center

frequency of its very narrow-band-pass filter to the frequency of a carrier signal Then when a noisy

signal is passed through the tuned filter the output of the filter will be the required fundamental

frequency component in the signal Tracking filters also are useful in obtaining amplitudendashfrequency

plots using an XndashY plotter In such cases the frequency value comes from the signal generator (sweep

oscillator) which produces the carrier signal to the tracking filter The tracking filter then determines the

corresponding amplitude of a signal that is fed into it Most tracking filters have dual channels so that two

signals can be handled (tracked) simultaneously

1314 Excitation Controller (Amplitude Servo-Monitor)

An excitation controller is typically an integral part of the signal generator It can be set so that automatic

sweep between two frequency limits can be performed at a selected sweep rate (linear or logarithmic)

More advanced excitation controllers have the capability of an automatic switch-over between constant-

displacement constant-velocity and constant-acceleration excitation-input control at specified

frequencies over the sweep frequency interval Consequently integrator circuits should be present

within the excitation controller unit to determine velocities and displacements from acceleration signals

Sometimes integration is performed by a separate unit called a vibration meter This unit also offers

the operator the capability of selecting the desired level of each signal (acceleration velocity or

displacement) There is an automatic cut-off level for large displacement values that could result from

noise in acceleration signals A compressor is also a subcomponent of the excitation controller The

complete unit is sometimes known as an amplitude servo-monitor

132 Signal-Generating Equipment

Shakers are force-generating devices that are operated using drive (excitation) signals generated from a

source The excitation-signal source is known as the signal generator Three major types of signal

generators are used in vibration testing applications (1) oscillators (2) random-signal generators and

(3) storage devices In some units oscillators and random-signal generators are combined We shall

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copy 2007 by Taylor amp Francis Group LLC

discuss these two generators separately however because of their difference in function It also should be

noted that almost any digital signal (deterministic or random) can be generated by a digital computer

using a suitable computer program the signal eventually can be passed through a DAC to obtain

the corresponding analog signal These lsquodigitalrsquo signal generators along with analog sources such as

magnetic tape players (FM) are classified into the category of storage devices

The dynamic range of equipment is the ratio of the maximum and minimum output levels (expressed

in decibels) at which it is capable of operating without significant error This is an important specification

for many types of equipment particularly for signal-generating devices The output level of the signal

generator should be set to a value within its dynamic range

1321 Oscillators

Oscillators are essentially single-frequency generators Typically sine signals are generated but other

waveforms (such as rectangular and triangular pulses) are also available in most oscillators Normally

an oscillator has two modes of operation (1) sweeping up and down between two frequency limits and

(2) dwelling at a specified frequency In the sweep operation the sweep rate should be specified This can

be done either on a linear scale (Hzmin) or on a logarithmic scale (octavesmin) In the dwell operation

the frequency points (or intervals) should be specified In either case a desired signal level can be chosen

using the gain-control knob An oscillator that is operated exclusively in the sweep mode is called a sweep

oscillator

The early generation of oscillators employed variable inductor-capacitor types of electronic circuits to

generate signals oscillating at a desired frequency The oscillator is tuned to the required frequency by

varying the capacitance or inductance parameters A DC voltage is applied to energize the capacitor

and to obtain the desired oscillating voltage signal which subsequently is amplified and conditioned

Modern oscillators use operational amplifier circuits along with resistor capacitor and semiconductor

(SC) elements Also common are crystal (quartz) parallel-resonance oscillators used to generate voltage

signals accurately at a fixed frequency The circuit is activated using a DC-voltage source Other

frequencies of interest are obtained by passing this high-frequency signal through a frequency converter

The signal is then conditioned (amplified and filtered) Required shaping (for example rectangular

pulse) is obtained using a shape circuit Finally the required signal level is obtained by passing the

resulting signal through a variable-gain amplifier A block diagram of an oscillator illustrating various

stages in the generation of a periodic signal is given in Figure 113

A typical oscillator offers a choice of several (typically six) linear and logarithmic frequency ranges and

a sizable level of control capability (for example 80 dB) Upper and lower frequency limits in a sweep can

be preset on the front panel to any of the available frequency ranges Sweep-rate settings are continuously

DC Voltage

Oscillator

FrequencySpecification

FrequencyConverter

FilterAmplifier

ShaperPeriodicSignal

FrequencyCounter

Fixed-FrequencySignal

Variable-GainOutput

Amplifier

SignalSpecification

LevelSpecification

FIGURE 113 Block diagram of an oscillator-type signal generator

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copy 2007 by Taylor amp Francis Group LLC

  • 53191fm
    • Vibration Monitoring Testing and Instrumentation
      • Preface
      • Acknowledgments
      • Editor-in-Chief
      • Contributors
      • Contents
      • Related Titles
          • 53191ch1
            • Table of Contents
            • Chapter 1 Vibration Instrumentation
              • Summary
              • 11 Introduction
              • 12 Vibration Exciters
                • 121 Shaker Selection
                  • 1211 Force Rating
                  • 1212 Power Rating
                  • 1213 Stroke Rating
                  • 1214 Hydraulic Shakers
                  • 1215 Inertial Shakers
                  • 1216 Electromagnetic Shakers
                    • 122 Dynamics of Electromagnetic Shakers
                      • 1221 Transient Exciters
                          • 13 Control System
                            • 131 Components of a Shaker Controller
                              • 1311 Compressor
                              • 1312 Equalizer (Spectrum Shaper)
                              • 1313 Tracking Filter
                              • 1314 Excitation Controller (Amplitude Servo-Monitor)
                                • 132 Signal-Generating Equipment
                                  • 1321 Oscillators
                                  • 1322 Random Signal Generators
                                  • 1323 Tape Players
                                  • 1324 Data Processing
                                      • 14 Performance Specification
                                        • 141 Parameters for Performance Specification
                                          • 1411 Time-Domain Specifications
                                          • 1412 Frequency-Domain Specifications
                                            • 142 Linearity
                                            • 143 Instrument Ratings
                                              • 1431 Rating Parameters
                                                • 144 Accuracy and Precision
                                                  • 15 Motion Sensors and Transducers
                                                    • 151 Potentiometer
                                                      • 1511 Potentiometer Resolution
                                                      • 1512 Optical Potentiometer
                                                        • 152 Variable-Inductance Transducers
                                                          • 1521 Mutual-Induction Transducers
                                                          • 1522 Linear-Variable Differential Transformer
                                                          • 1523 Signal Conditioning
                                                            • 153 Mutual-Induction Proximity Sensor
                                                            • 154 Selfinduction Transducers
                                                            • 155 Permanent-Magnet Transducers
                                                            • 156 Alternating Current Permanent-Magnet Tachometer
                                                            • 157 Alternating Current Induction Tachometer
                                                            • 158 Eddy Current Transducers
                                                            • 159 Variable-Capacitance Transducers
                                                              • 1591 Capacitive Displacement Sensors
                                                              • 1592 Capacitive Angular Velocity Sensor
                                                              • 1593 Capacitance Bridge Circuit
                                                                • 1510 Piezoelectric Transducers
                                                                  • 15101 Sensitivity
                                                                  • 15102 Piezoelectric Accelerometer
                                                                  • 15103 Charge Amplifier
                                                                      • 16 Torque Force and Other Sensors
                                                                        • 161 Strain Gage Sensors
                                                                          • 1611 Equations for Strain Gage Measurements
                                                                          • 1612 Bridge Sensitivity
                                                                          • 1613 The Bridge Constant
                                                                          • 1614 The Calibration Constant
                                                                          • 1615 Data Acquisition
                                                                          • 1616 Accuracy Considerations
                                                                          • 1617 Semiconductor Strain Gages
                                                                          • 1618 Force and Torque Sensors
                                                                          • 1619 Strain Gage Torque Sensors
                                                                          • 16110 Deflection Torque Sensors
                                                                          • 16111 Variable-Reluctance Torque Sensor
                                                                          • 16112 Reaction Torque Sensors
                                                                            • 162 Miscellaneous Sensors
                                                                              • 1621 Stroboscope
                                                                              • 1622 Fiber Optic Sensors and Lasers
                                                                              • 1623 Fiber-Optic Gyroscope
                                                                              • 1624 Laser Doppler Interferometer
                                                                              • 1625 Ultrasonic Sensors
                                                                              • 1626 Gyroscopic Sensors
                                                                                  • References
                                                                                  • Appendix 1A Virtual Instrumentation for Data Acquisition Analysis and Presentation
                                                                                    • Summary
                                                                                    • List of Abbreviations
                                                                                    • 1A1 Dynamic Signals
                                                                                      • 1A11 Acquiring and Simulating Dynamic Signals
                                                                                        • 1A111 Aliasing
                                                                                        • 1A112 Time Continuity
                                                                                            • 1A2 Measurement Configuration Considerations
                                                                                              • 1A21 Input Signal Considerations
                                                                                                • 1A211 Input Pseudodifferential and Differential Configuration
                                                                                                • 1A212 Gain
                                                                                                • 1A213 Input Coupling
                                                                                                • 1A214 Integrated Electronic Piezoelectric Excitation
                                                                                                • 1A215 Nyquist Frequency and Bandwidth
                                                                                                • 1A216 Analog-to-Digital Conversion
                                                                                                • 1A217 Antialias Filters
                                                                                                • 1A218 Input Filter Delay
                                                                                                • 1A219 Overload Detection
                                                                                                  • 1A22 Output Signal Considerations
                                                                                                    • 1A221 Output Pseudodifferential and Differential Configuration
                                                                                                    • 1A222 Attenuation
                                                                                                    • 1A223 Digital-to-Analog Conversion
                                                                                                    • 1A224 Anti-imaging and Interpolation Filters
                                                                                                    • 1A225 Output Filter Delay
                                                                                                        • 1A3 Scaling and Calibration
                                                                                                          • 1A31 Scaling to Engineering Units
                                                                                                          • 1A32 Performing System Calibration
                                                                                                            • 1A321 Propagation Delay Calibration
                                                                                                                • 1A4 Limit Testing Analysis
                                                                                                                  • 1A41 Limit Testing Overview
                                                                                                                  • 1A42 Using the SVT Limit Testing VI
                                                                                                                    • 1A5 Integration
                                                                                                                      • 1A51 Introduction to Integration
                                                                                                                      • 1A52 Implementing Integration
                                                                                                                        • 1A521 Challenges when Integrating Vibration Data
                                                                                                                          • 1A53 Time-Domain Integration
                                                                                                                            • 1A531 Single-Shot Acquisition and Integration
                                                                                                                            • 1A532 Continuous Acquisition and Integration
                                                                                                                              • 1A54 Frequency-Domain Integration
                                                                                                                                • 1A6 Vibration-Level Measurements
                                                                                                                                  • 1A61 Measuring the Root Mean Square Level
                                                                                                                                    • 1A611 Single-Shot Buffered Acquisition
                                                                                                                                    • 1A612 Continuous Signal Acquisition
                                                                                                                                      • 1A62 Performing a Running RMS Level Measurement
                                                                                                                                      • 1A63 Computing the Peak Level
                                                                                                                                      • 1A64 Computing the Crest Factor
                                                                                                                                        • 1A7 Frequency Analysis
                                                                                                                                          • 1A71 FFT Fundamentals
                                                                                                                                            • 1A711 Number of Samples
                                                                                                                                            • 1A712 Frequency Resolution
                                                                                                                                            • 1A713 Maximum Resolvable Frequency
                                                                                                                                            • 1A714 Minimum Resolvable Frequency
                                                                                                                                            • 1A715 Number of Spectral Lines
                                                                                                                                            • 1A716 Relationship between Time-Domain and Frequency-Domain Specifications and Parameters
                                                                                                                                              • 1A72 Increasing Frequency Resolution
                                                                                                                                                • 1A721 Zoom FFT Analysis
                                                                                                                                                • 1A722 Frequency Resolution of the Zoom FFT VIs
                                                                                                                                                • 1A723 Zoom Measurement
                                                                                                                                                • 1A724 Zoom Settings
                                                                                                                                                • 1A725 Subset Analysis
                                                                                                                                                    • 1A8 Transient Analysis
                                                                                                                                                      • 1A81 Transient Analysis with the Sound and Vibration Toolkit
                                                                                                                                                      • 1A82 Performing an STFT vs Time
                                                                                                                                                        • 1A821 Selecting the FFT Block Size
                                                                                                                                                        • 1A822 Overlapping
                                                                                                                                                        • 1A823 Using the SVT STFT vs Time VI
                                                                                                                                                          • 1A83 Performing an STFT vs Rotational Speed
                                                                                                                                                            • 1A831 Converting the Pulse Train to Rotational Speed
                                                                                                                                                            • 1A832 STFT vs RPM
                                                                                                                                                              • 1A84 Measuring a Shock Response Spectrum
                                                                                                                                                                • 1A9 Waterfall Display
                                                                                                                                                                  • 1A91 Using the Display VIs
                                                                                                                                                                    • 1A911 Initializing the Display
                                                                                                                                                                    • 1A912 Sending Data to the Display
                                                                                                                                                                    • 1A913 Waterfall Display for Frequency Analysis
                                                                                                                                                                    • 1A914 Waterfall Display for Transient Analysis
                                                                                                                                                                    • 1A915 Waterfall Display for Octave Spectra
                                                                                                                                                                        • 1A10 Swept-Sine Measurements
                                                                                                                                                                          • 1A101 Swept-Sine Overview
                                                                                                                                                                          • 1A102 Choosing Swept-Sine vs FFT Measurements
                                                                                                                                                                          • 1A103 Taking a Swept-Sine Measurement
                                                                                                                                                                          • 1A104 Swept-Sine Measurement Example
                                                                                                                                                                              • Bibliography
                                                                                                                                                                              • Related Titles
                                                                                                                                                                                  • 53191ch2
                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                    • Chapter 2 Signal Conditioning and Modification
                                                                                                                                                                                      • Summary
                                                                                                                                                                                      • 21 Introduction
                                                                                                                                                                                      • 22 Amplifiers
                                                                                                                                                                                        • 221 Operational Amplifier
                                                                                                                                                                                        • 222 Use of Feedback in Opamp
                                                                                                                                                                                        • 223 Voltage Current and Power Amplifiers
                                                                                                                                                                                          • 2231 Charge Amplifiers
                                                                                                                                                                                            • 224 Instrumentation Amplifiers
                                                                                                                                                                                              • 2241 Differential Amplifier
                                                                                                                                                                                              • 2242 Common Mode
                                                                                                                                                                                                • 225 Amplifier Performance Ratings
                                                                                                                                                                                                  • 2251 Common-Mode Rejection Ratio
                                                                                                                                                                                                    • 226 Component Interconnection
                                                                                                                                                                                                      • 2261 Impedance Characteristics
                                                                                                                                                                                                      • 2262 Cascade Connection of Devices
                                                                                                                                                                                                      • 2263 AC-Coupled Ampliers
                                                                                                                                                                                                          • 23 Analog Filters
                                                                                                                                                                                                            • 231 Passive Filters and Active Filters
                                                                                                                                                                                                              • 2311 Number of Poles
                                                                                                                                                                                                                • 232 Low-Pass Filters
                                                                                                                                                                                                                  • 2321 Low-Pass Butterworth Filter
                                                                                                                                                                                                                    • 233 High-Pass Filters
                                                                                                                                                                                                                    • 234 Band-Pass Filters
                                                                                                                                                                                                                      • 2341 Resonance-Type Band-Pass Filters
                                                                                                                                                                                                                        • 235 Band-Reject Filters
                                                                                                                                                                                                                          • 24 Modulators and Demodulators
                                                                                                                                                                                                                            • 241 Amplitude Modulation
                                                                                                                                                                                                                              • 2411 Modulation Theorem
                                                                                                                                                                                                                              • 2412 Side Frequencies and Side Bands
                                                                                                                                                                                                                                • 242 Application of Amplitude Modulation
                                                                                                                                                                                                                                  • 2421 Fault Detection and Diagnosis
                                                                                                                                                                                                                                    • 243 Demodulation
                                                                                                                                                                                                                                      • 25 Analog ndashDigital Conversion
                                                                                                                                                                                                                                        • 251 Digital-to-Analog Conversion
                                                                                                                                                                                                                                          • 2511 DAC Error Sources
                                                                                                                                                                                                                                            • 252 Analog-to-Digital Conversion
                                                                                                                                                                                                                                            • 253 Analog-to-Digital Converter Performance Characteristics
                                                                                                                                                                                                                                              • 2531 Resolution and Quantization Error
                                                                                                                                                                                                                                              • 2532 Monotonicity Nonlinearity and Offset Error
                                                                                                                                                                                                                                              • 2533 Analog-to-Digital Converter Conversion Rate
                                                                                                                                                                                                                                                • 254 Sample-and-Hold Circuitry
                                                                                                                                                                                                                                                • 255 Digital Filters
                                                                                                                                                                                                                                                  • 2551 Software Implementation and Hardware Implementation
                                                                                                                                                                                                                                                      • 26 Bridge Circuits
                                                                                                                                                                                                                                                        • 261 Wheatstone Bridge
                                                                                                                                                                                                                                                        • 262 Constant-Current Bridge
                                                                                                                                                                                                                                                        • 263 Bridge Amplifiers
                                                                                                                                                                                                                                                          • 2631 Half-Bridge Circuits
                                                                                                                                                                                                                                                            • 264 Impedance Bridges
                                                                                                                                                                                                                                                              • 2641 Owen Bridge
                                                                                                                                                                                                                                                              • 2642 Wien-Bridge Oscillator
                                                                                                                                                                                                                                                                  • 27 Linearizing Devices
                                                                                                                                                                                                                                                                    • 271 Linearization by Software
                                                                                                                                                                                                                                                                    • 272 Linearization by Hardware Logic
                                                                                                                                                                                                                                                                    • 273 Analog Linearizing Circuitry
                                                                                                                                                                                                                                                                    • 274 Offsetting Circuitry
                                                                                                                                                                                                                                                                    • 275 Proportional-Output Circuitry
                                                                                                                                                                                                                                                                      • 2751 Curve-Shaping Circuitry
                                                                                                                                                                                                                                                                          • 28 Miscellaneous Signal Modification Circuitry
                                                                                                                                                                                                                                                                            • 281 Phase Shifters
                                                                                                                                                                                                                                                                            • 282 Voltage-to-Frequency Converter
                                                                                                                                                                                                                                                                            • 283 Frequency-to-Voltage Converter
                                                                                                                                                                                                                                                                            • 284 Voltage-to-Current Converters
                                                                                                                                                                                                                                                                            • 285 Peak-Hold Circuits
                                                                                                                                                                                                                                                                              • 29 Signal Analyzers and Display Devices
                                                                                                                                                                                                                                                                                • 291 Signal Analyzers
                                                                                                                                                                                                                                                                                • 292 Oscilloscopes
                                                                                                                                                                                                                                                                                  • 2921 Triggering
                                                                                                                                                                                                                                                                                  • 2922 Lissajous Patterns
                                                                                                                                                                                                                                                                                  • 2923 Digital Oscilloscopes
                                                                                                                                                                                                                                                                                      • Bibliography
                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                          • 53191ch3
                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                            • Chapter 3 Vibration Testing
                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                              • 31 Introduction
                                                                                                                                                                                                                                                                                              • 32 Representation of a Vibration Environment
                                                                                                                                                                                                                                                                                                • 321 Test Signals
                                                                                                                                                                                                                                                                                                  • 3211 Stochastic vs Deterministic Signals
                                                                                                                                                                                                                                                                                                    • 322 Deterministic Signal Representation
                                                                                                                                                                                                                                                                                                      • 3221 Single-Frequency Signals
                                                                                                                                                                                                                                                                                                      • 3222 Sine Sweep
                                                                                                                                                                                                                                                                                                      • 3223 Sine Dwell
                                                                                                                                                                                                                                                                                                      • 3224 Decaying Sine
                                                                                                                                                                                                                                                                                                      • 3225 Sine Beat
                                                                                                                                                                                                                                                                                                      • 3226 Sine Beat with Pauses
                                                                                                                                                                                                                                                                                                      • 3227 Multifrequency Signals
                                                                                                                                                                                                                                                                                                      • 3228 Actual Excitation Records
                                                                                                                                                                                                                                                                                                      • 3229 Simulated Excitation Signals
                                                                                                                                                                                                                                                                                                        • 323 Stochastic Signal Representation
                                                                                                                                                                                                                                                                                                          • 3231 Ergodic Random Signals
                                                                                                                                                                                                                                                                                                          • 3232 Stationary Random Signals
                                                                                                                                                                                                                                                                                                          • 3233 Independent and Uncorrelated Signals
                                                                                                                                                                                                                                                                                                          • 3234 Transmission of Random Excitations
                                                                                                                                                                                                                                                                                                            • 324 Frequency-Domain Representations
                                                                                                                                                                                                                                                                                                              • 3241 Fourier Spectrum Method
                                                                                                                                                                                                                                                                                                              • 3242 Power Spectral Density Method
                                                                                                                                                                                                                                                                                                                • 325 Response Spectrum
                                                                                                                                                                                                                                                                                                                  • 3251 Displacement Velocity and Acceleration Spectra
                                                                                                                                                                                                                                                                                                                  • 3252 Response-Spectra Plotting Paper
                                                                                                                                                                                                                                                                                                                  • 3253 Zero-Period Acceleration
                                                                                                                                                                                                                                                                                                                  • 3254 Uses of Response Spectra
                                                                                                                                                                                                                                                                                                                    • 326 Comparison of Various Representations
                                                                                                                                                                                                                                                                                                                      • 33 Pretest Procedures
                                                                                                                                                                                                                                                                                                                        • 331 Purpose of Testing
                                                                                                                                                                                                                                                                                                                        • 332 Service Functions
                                                                                                                                                                                                                                                                                                                          • 3321 Active Equipment
                                                                                                                                                                                                                                                                                                                          • 3322 Passive Equipment
                                                                                                                                                                                                                                                                                                                          • 3323 Functional Testing
                                                                                                                                                                                                                                                                                                                            • 333 Information Acquisition
                                                                                                                                                                                                                                                                                                                              • 3331 Interface Details
                                                                                                                                                                                                                                                                                                                              • 3332 Effect of Neglecting Interface Dynamics
                                                                                                                                                                                                                                                                                                                              • 3333 Effects of Damping
                                                                                                                                                                                                                                                                                                                              • 3334 Effects of Inertia
                                                                                                                                                                                                                                                                                                                              • 3335 Effect of Natural Frequency
                                                                                                                                                                                                                                                                                                                              • 3336 Effect of Excitation Frequency
                                                                                                                                                                                                                                                                                                                              • 3337 Other Effects of Interface
                                                                                                                                                                                                                                                                                                                                • 334 Test-Program Planning
                                                                                                                                                                                                                                                                                                                                  • 3341 Testing of Cabinet-Mounted Equipment
                                                                                                                                                                                                                                                                                                                                    • 335 Pretest Inspection
                                                                                                                                                                                                                                                                                                                                      • 34 Testing Procedures
                                                                                                                                                                                                                                                                                                                                        • 341 Resonance Search
                                                                                                                                                                                                                                                                                                                                        • 342 Methods of Determining Frequency-Response Functions
                                                                                                                                                                                                                                                                                                                                          • 3421 Fourier Transform Method
                                                                                                                                                                                                                                                                                                                                          • 3422 Spectral Density Method
                                                                                                                                                                                                                                                                                                                                          • 3423 Harmonic Excitation Method
                                                                                                                                                                                                                                                                                                                                            • 343 Resonance-Search Test Methods
                                                                                                                                                                                                                                                                                                                                              • 3431 Hammer (Bump) Test and Drop Test
                                                                                                                                                                                                                                                                                                                                              • 3432 Pluck Test
                                                                                                                                                                                                                                                                                                                                              • 3433 Shaker Tests
                                                                                                                                                                                                                                                                                                                                                • 344 Mechanical Aging
                                                                                                                                                                                                                                                                                                                                                  • 3441 Equivalence for Mechanical Aging
                                                                                                                                                                                                                                                                                                                                                  • 3442 Excitation-Intensity Equivalence
                                                                                                                                                                                                                                                                                                                                                  • 3443 Dynamic-Excitation Equivalence
                                                                                                                                                                                                                                                                                                                                                  • 3444 Cumulative Damage Theory
                                                                                                                                                                                                                                                                                                                                                    • 345 Test-Response Spectrum Generation
                                                                                                                                                                                                                                                                                                                                                    • 346 Instrument Calibration
                                                                                                                                                                                                                                                                                                                                                    • 347 Test-Object Mounting
                                                                                                                                                                                                                                                                                                                                                    • 348 Test-Input Considerations
                                                                                                                                                                                                                                                                                                                                                      • 3481 Test Nomenclature
                                                                                                                                                                                                                                                                                                                                                      • 3482 Testing with Uncorrelated Excitations
                                                                                                                                                                                                                                                                                                                                                      • 3483 Symmetrical Rectilinear Testing
                                                                                                                                                                                                                                                                                                                                                      • 3484 Geometry vs Dynamics
                                                                                                                                                                                                                                                                                                                                                      • 3485 Some Limitations
                                                                                                                                                                                                                                                                                                                                                      • 3486 Testing Black Boxes
                                                                                                                                                                                                                                                                                                                                                      • 3487 Phasing of Excitations
                                                                                                                                                                                                                                                                                                                                                      • 3488 Testing a Gray or White Box
                                                                                                                                                                                                                                                                                                                                                      • 3489 Overtesting in Multitest Sequences
                                                                                                                                                                                                                                                                                                                                                          • 35 Some Practical Information
                                                                                                                                                                                                                                                                                                                                                            • 351 Random Vibration Test Example
                                                                                                                                                                                                                                                                                                                                                            • 352 Vibration Shakers and Control Systems
                                                                                                                                                                                                                                                                                                                                                              • Bibliography
                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                  • 53191ch4
                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                    • Chapter 4 Experimental Modal Analysis
                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                      • 41 Introduction
                                                                                                                                                                                                                                                                                                                                                                      • 42 Frequency-Domain Formulation
                                                                                                                                                                                                                                                                                                                                                                        • 421 Transfer-Function Matrix
                                                                                                                                                                                                                                                                                                                                                                        • 422 Principle of Reciprocity
                                                                                                                                                                                                                                                                                                                                                                          • 43 Experimental Model Development
                                                                                                                                                                                                                                                                                                                                                                            • 431 Extraction of the Time-Domain Model
                                                                                                                                                                                                                                                                                                                                                                              • 44 Curve Fitting of Transfer Functions
                                                                                                                                                                                                                                                                                                                                                                                • 441 Problem Identification
                                                                                                                                                                                                                                                                                                                                                                                • 442 Single- and Multi-Degree-of-Freedom Techniques
                                                                                                                                                                                                                                                                                                                                                                                • 443 Single-Degree-of-Freedom Parameter Extraction in the Frequency Domain
                                                                                                                                                                                                                                                                                                                                                                                  • 4431 Circle-Fit Method
                                                                                                                                                                                                                                                                                                                                                                                    • Case of Viscous Damping
                                                                                                                                                                                                                                                                                                                                                                                    • Case of Hysteretic Damping
                                                                                                                                                                                                                                                                                                                                                                                      • 4432 Peak-Picking Method
                                                                                                                                                                                                                                                                                                                                                                                        • 444 Multi-Degree of Freedom Curve Fitting
                                                                                                                                                                                                                                                                                                                                                                                          • 4441 Formulation of the Method
                                                                                                                                                                                                                                                                                                                                                                                            • 445 A Comment on Static Modes and Rigid-Body Modes
                                                                                                                                                                                                                                                                                                                                                                                            • 446 Residue Extraction
                                                                                                                                                                                                                                                                                                                                                                                              • 45 Laboratory Experiments
                                                                                                                                                                                                                                                                                                                                                                                                • 451 Lumped-Parameter System
                                                                                                                                                                                                                                                                                                                                                                                                  • 4511 Frequency-Domain Test
                                                                                                                                                                                                                                                                                                                                                                                                  • 4512 Time-Domain Tests
                                                                                                                                                                                                                                                                                                                                                                                                    • 452 Distributed-Parameter System
                                                                                                                                                                                                                                                                                                                                                                                                      • 46 Commercial EMA Systems
                                                                                                                                                                                                                                                                                                                                                                                                        • 461 System Configuration
                                                                                                                                                                                                                                                                                                                                                                                                          • 4611 FFT Analysis Options
                                                                                                                                                                                                                                                                                                                                                                                                          • 4612 Modal Analysis Components
                                                                                                                                                                                                                                                                                                                                                                                                              • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                  • 53191ch5
                                                                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                    • Chapter 5 Mechanical Shock
                                                                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                      • 51 Definitions
                                                                                                                                                                                                                                                                                                                                                                                                                        • 511 Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 512 Simple (or Perfect) Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 513 Half-Sine Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 514 Versed-Sine (or Haversine) Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 515 Terminal Peak Sawtooth Shock or Final Peak Sawtooth Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 516 Rectangular Shock
                                                                                                                                                                                                                                                                                                                                                                                                                          • 5161 Trapezoidal Shock
                                                                                                                                                                                                                                                                                                                                                                                                                              • 52 Description in the Time Domain
                                                                                                                                                                                                                                                                                                                                                                                                                              • 53 Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                • 531 Need
                                                                                                                                                                                                                                                                                                                                                                                                                                • 532 Shock Response Spectrum Definition
                                                                                                                                                                                                                                                                                                                                                                                                                                • 533 Response of a Linear One-Degree-of-Freedom System
                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5331 Shock Defined by a Force
                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5332 Shock Defined by an Acceleration
                                                                                                                                                                                                                                                                                                                                                                                                                                    • 534 Definitions
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5341 Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5342 Absolute Acceleration Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5343 Relative Displacement Shock Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5344 Primary Positive Shock Response Spectrum or Initial Positive Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5345 Primary (or Initial) Negative Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5346 Secondary (or Residual) Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5347 Positive (or Maximum Positive) Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5348 Negative (or Maximum Negative) Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5349 Maximax Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53410 Choice of Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                        • 535 Standardized Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5351 Definition
                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5352 Standardized Shock Response Spectra of Simple Shocks
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53521 Half-Sine Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53522 Versed Sine Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53523 Terminal Peak Sawtooth Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53524 Rectangular Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53525 Trapezoidal Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 536 Choice of Damping
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 537 Shock Response Spectra Domains
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 538 Algorithms for Calculation of the Shock Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 539 Choice of the Digitization Frequency of the Signal
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5310 Use of Shock Response Spectra for the Study of Systems with Several Degrees of Freedom
                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 54 Pyroshocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 55 Use of Shock Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 551 Severity Comparison of Several Shocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 552 Test Specification Development from Real Environment Data
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5521 Synthesis of Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5522 Nature of the Specification
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5523 Choice of Shape
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5524 Amplitude
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5525 Duration
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5526 Difficulties
                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 56 Standards
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 561 Types of Standards
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 562 Installation Conditions of Test Item
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 563 Uncertainty Factor
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 564 Bump Test
                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 57 Damage Boundary Curve
                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 571 Definition
                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 572 Analysis of Test Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 58 Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 581 Main Types
                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 582 Impact Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5821 Universal Shock-Test Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 58211 Impact Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 58212 Impulse Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 583 Shock Simulators (Programmers)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5831 Half-Sine Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58311 Shock Duration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58312 Impact Velocity
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58313 Maximum Deformation of the Shock Simulator (Programmer)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58314 Shock Amplitude
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58315 Characteristics of the Target
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5832 Terminal Peak Sawtooth Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5833 Rectangular Pulse ndash Trapezoidal Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5834 Universal Shock Simulator (Programmer)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 58341 Generating a Half-Sine Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 58342 Generating a Terminal Peak Sawtooth Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 58343 Trapezoidal Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 584 Limitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5841 Limitations of the Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5842 Limitations of Shock Simulators
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 585 Pneumatic Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 586 High Impact Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5861 Lightweight High Impact Shock Machine
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5862 Medium Weight High Impact Shock Machine
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 587 Specific Test Facilities
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 59 Generation of Shock Using Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 591 Principle Behind the Generation of a Simple Shape Signal versus Time
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 592 Main Advantages
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 593 Pre- and Postshocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5931 Requirements
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5932 Solutions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 59321 Optimized Pre- and Postpulses
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5933 Incidence on the Shock Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 594 Limitations of Electrodynamic Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5941 Mechanical Limitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 59411 Abacuses
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5942 Electronic Limitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 595 The Use of Electrohydraulic Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 510 Control by a Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 5101 Principle
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 5102 Principal Shapes of Elementary Signals
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 51021 Decaying Sinusoid
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 51022 ZERD Function
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 51023 WAVSIN Waveform
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 5103 Comparison of WAVSIN SHOC Waveforms and Decaying Sinusoid
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 5104 Criticism of Control by a Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 511 Pyrotechnic Shock Simulation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5111 Simulation Using Pyrotechnic Facilities
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5112 Simulation Using Metal-to-Metal Impact
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5113 Simulation Using Electrodynamic Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5114 Simulation Using Conventional Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53191ch6
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Chapter 6 Machine Condition Monitoring and Fault Diagnostics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 61 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 62 Machinery Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 621 Causes of Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 622 Types of Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 623 Frequency of Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 63 Basic Maintenance Strategies
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 631 Run-to-Failure (Breakdown) Maintenance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 632 Scheduled (Preventative) Maintenance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 633 Condition-Based (Predictive Proactive Reliability Centered On-Condition) Maintenance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 64 Factors Which Influence Maintenance Strategy
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 65 Machine Condition Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 651 Periodic Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 652 Continuous Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 66 Transducer Selection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 661 Noncontact Displacement Transducers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 662 Velocity Transducers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 663 Acceleration Transducers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 67 Transducer Location
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 68 Recording and Analysis Instrumentation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 681 Vibration Meters
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 682 Data Collectors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 683 Frequency-Domain Analyzers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 684 Time-Domain Instruments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 685 Tracking Analyzers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 69 Display Formats and Analysis Tools
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 691 Time Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6911 Time-Waveform Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6912 Time-Waveform Indices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6913 Time-Synchronous Averaging
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6914 Negative Averaging
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6915 Orbits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6916 Probability Density Functions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6917 Probability Density Moments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 692 Frequency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6921 Band-Pass Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6922 Shock Pulse (Spike Energy)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6923 Enveloped Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6924 Signature Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6925 Cascades (Waterfall Plots)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6926 Masks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6927 Frequency-Domain Indices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 693 Modal Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 694 Quefrency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 610 Fault Detection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 6101 Standards
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61011 Standards Based on Machinery Type
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61012 Standards Based on Vibration Severity
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 6102 Acceptance Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 61021 Statistical Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 6103 Frequency-Domain Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61031 Limited Band Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61032 Constant Bandwidth Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61033 Constant Percentage Bandwidth Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 611 Fault Diagnostics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 6111 Forcing Functions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61111 Unbalance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61112 Misalignment
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61113 Mechanical Looseness
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61114 Soft Foot
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61115 Rubs
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61116 Resonances
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61117 Oil Whirl
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61118 Oil Whip
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61119 Structural Vibrations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 611110 Foundation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 6112 Specific Machine Components
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 61121 Damaged or Worn Rolling-Element Bearings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 61122 Damaged or Worn Gears
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 6113 Specific Machine Types
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61131 Pumps
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61132 Fans
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61133 Electric Motors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61134 Steam and Gas Turbines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61135 Compressors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61136 Reciprocating Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 6114 Advanced Fault Diagnostic Techniques
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 53191ch7
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • Chapter 7 Vibration-Based Tool Condition Monitoring Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 71 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 72 Mechanics of Turning
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 721 General Terms
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 722 Chatter Vibrations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 723 Tool Wear
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7231 Tool Failure Mechanisms
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7232 Tool Failure Modes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7233 Tool Wear Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7234 Tool Wear Stages
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 73 Vibration Signal Recording
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 731 Direct and Indirect Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 732 Sensor Requirements for Tool Wear Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 733 Force Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7331 Direct Measurement Dynamometers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7332 Indirect Force Sensors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7333 Piezoelectric Strain Sensors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7334 Resistance Strain Gauges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7335 Customized Force Sensors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 734 Acceleration Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 735 Acoustic Emission Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 736 Sensor Comparisons
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 74 Signal Processing for Sensor-Based Tool Condition Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 741 Feature Extraction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7411 Time Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7412 Frequency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7413 Statistical Processing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7414 TimendashFrequency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 742 Feature Selection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 75 Wear ModelDecision-Making for Sensor-Based Tool Condition Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 751 Trending Threshold
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 752 Neural Networks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7521 Unsupervised Networks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7522 Supervised Networks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 753 Fuzzy Logic
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 754 Other Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 76 Conclusion
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53191ch8
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Chapter 8 Fault Diagnosis of Helicopter Gearboxes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 81 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 82 Abnormality Scaling
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 83 The Structure-Based Connectionist Network
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 84 Sensor Location Selection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 841 Coverage Index
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 842 Overlap Index
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 843 Monitoring Effectiveness
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 85 A Case Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 851 Structural and Featural Influences
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 852 Evaluation of Influences
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 853 Fault Detection Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 854 Fault Diagnostic Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 8541 Faulty Subsystem Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 8542 Faulty Component Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 855 Sensor Location Evaluation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 856 Sensor Location Validation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 86 Conclusion
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 53191ch9
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Chapter 9 Vibration Suppression and Monitoring in Precision Motion Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 91 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 92 Mechanical Design to Minimize Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 921 Stability and Static Determinacy of Machine Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 922 Two-Dimensional Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 923 Three-Dimensional Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 93 Adaptive Notch Filter
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 931 Fast Fourier Transform
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 932 Simulation and Experiments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 94 Real-Time Vibration Analyzer
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 941 Learning Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 942 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 943 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 944 Experiments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 9441 Input Variables mdash the Evaluation Criteria
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 94411 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 94412 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 9442 Evaluation Rules
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 94421 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 94422 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 9443 Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 94431 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 94432 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 95 Practical Insights and Case Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 96 Conclusions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 53191ch10
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Chapter 10 Vibration and Shock Problems of Civil Engineering Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 101 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 102 Earthquake-Induced Vibration of Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1021 Seismicity and Ground Motions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1022 Influence of Local Site Conditions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1023 Response of Structures to Ground Motions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1024 Dynamic Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10241 Equations of Motion for Linear Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10242 Equations of Motion for Linear Multiple-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1025 Earthquake Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10251 Elastic Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10252 Smoothed Design Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10253 Ductility-Modified Response Spectrum Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1026 Design Philosophy and the Code Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10261 Performance-Based Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1027 Analysis Options for Earthquake Effects
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10271 Dynamic Time History Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10272 Response Spectrum Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 102721 Response Spectrum Analysis of Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 102722 Response Spectrum Analysis of Multi-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10273 Equivalent Static Analysis (Force-Based Approach)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10274 Displacement-Based Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1028 SoilndashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1029 Active and Passive Control Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 10210 Worked Examples
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 103 Dynamic Effects of Wind Loading on Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1031 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1032 Wind Speed
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1033 Design Structures for Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10331 Types of Wind Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10332 Design Criteria
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10333 Static Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1034 Along and Across-Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10341 Along-Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10342 Across-Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1035 Wind Tunnel Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1036 Comfort Criteria Human Response to Building Motion
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1037 Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1038 Comparison with Earthquake Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 104 Vibrations Due to Fluid ndashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1041 Added Mass and Inertial Coupling
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1042 Wave-Induced Vibration of Structure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 105 Blast Loading and Blast Effects on Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1051 Explosions and Blast Phenomenon
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1052 Explosive Air-Blast Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10521 Blast Wave Scaling Laws
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10522 Prediction of Blast Pressure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1053 Gas Explosion Loading and Effect of Internal Explosions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1054 Structural Response to Blast Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10541 Elastic Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10542 Elasto-Plastic Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1055 Material Behaviors at High Strain Rate
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10551 Dynamic Properties of Concrete under High Strain Rates
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10552 Dynamic Properties of Reinforcing Steel under High Strain Rates
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1056 Failure Modes of Blast-Loaded Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10561 Global Structural Behavior
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10562 Localized Structural Behavior
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10563 PressurendashImpulse ( PndashI ) Diagrams
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1057 Blast WavendashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1058 Effect of Ground Shocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10581 Loads from Air-Induced Ground Shock
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10582 Loads from Direct Ground Shock
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1059 Technical Design Manuals for Blast-Resistant Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 10510 Computer Programs for Blast and Shock Effects
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 106 Impact Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1061 Structural Impact between Two Bodies mdash Hard Impact and Soft Impact
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1062 Example mdash Aircraft Impact
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 107 Floor Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1071 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1072 Types of Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10721 Walking
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10722 Rhythmic Activities
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10723 Mechanical Equipment
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10724 Analysis Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1073 Natural Frequency of Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10731 Computing the Natural Frequency
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10732 Computing Deflection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10733 Damping
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10734 Resonance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1074 Vibration Caused by Walking
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10741 Minimum Natural Frequency
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1075 Design for Rhythmic Excitation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10751 Harmonics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10752 Minimum Natural Frequency
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1076 Example mdash Vibration Analysis of a Reinforced Concrete Floor
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 53191ch11
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Chapter 11 Seismic Base Isolation and Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 111 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1111 From Ductility Design to Base Isolation and Control Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1112 The Importance of Reducing Seismic Input and Response
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 112 Seismic Base Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1121 Historical Development of Base Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1122 Basic Principle
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1123 Issues in Seismic Base Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11231 Performance Criteria
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11232 Type of Structure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11233 Site Characteristics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11234 Retrofit Issues
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11235 Design of Building Services
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11236 Expected Life of Isolator
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1124 Seismic Isolation Devices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11241 Laminated Rubber Bearings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11242 Lead Rubber Bearing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11243 Friction-Based Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11244 Other Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1125 Design of Isolation Devices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11251 High-Damping Rubber Bearing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112511 Stability against Buckling
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112512 Stability against Roll Out
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11252 Lead Rubber Bearings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112521 Design of Lead Plug
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112522 Design of Laminated Rubber Bearing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11253 Design of Friction Pendulum System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1126 Verification of Properties of Isolation Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11261 Tests for Isolation Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 112611 System Characterization Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 112612 Prototype Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 112613 Quality Control Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11262 Uniform Building Code Recommendations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112621 Units Dependent on Loading Rates
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112622 Units Dependent on Bilateral Load
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112623 System Adequacy
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1127 Analysis of Base-Isolated Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11271 Modeling of a Superstructure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11272 Modeling of Isolation System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11273 Static Analysis Procedure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11274 Dynamic Analysis Procedure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 112741 Response Spectrum Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 112742 Time-History Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11275 Software for Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1128 Experimental Methods for Isolated Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1129 Implementation of Seismic Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11291 New Construction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112911 Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112912 Bridges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11292 Seismic Retrofit
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112921 Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112922 Bridges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11293 Other Implementations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 11210 Performance during Past Earthquakes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 112101 Performance of Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 112102 Performance of Bridges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 113 Seismic Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1131 Historical Development of Seismic Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1132 Basic Principles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11321 Passive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11322 Active Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11323 Semiactive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11324 Hybrid Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11325 Categorization of Basic Principles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1133 Important Issues in Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11331 SoilndashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11332 DevicendashStructure Interaction and Time Delay
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11333 Design Guidelines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1134 Vibration-Control Devices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11341 Passive Control Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113411 Metallic Yielding Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113412 Friction Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113413 Viscoelastic Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113414 Viscous Fluid Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113415 Tuned Mass Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11342 Active Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113421 Electromagnetic Actuator
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113422 Hydraulic Actuators
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11343 Semiactive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113431 Variable-Orifice Hydraulic Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113432 Controllable Fluid Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113433 Controllable Friction Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11344 Hybrid Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1135 Control Algorithm
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11351 Active Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11352 Semiactive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113521 Common Control Schemes for Controllable Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113522 Special Control Schemes for Controllable Damper
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1136 Experimental Performance Verification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11361 Shaking Table Tests of a Flexible Structural Model with TMD AMD and ATMD
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11362 Substructure Hybrid Test
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113621 Hybrid Tests Using Hydraulic Actuator
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113622 Hybrid Tests Using Shaking Table
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113623 Hybrid Tests Using Inertia-Force-Driven Loading System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1137 Implementations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11371 Semiactive Control of Full-Scale Structures Using Variable Joint Damper System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113711 Background of Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113712 Test System Set Up
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113713 Control Algorithm
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113714 Test Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11372 Application of Structural Control Technologies to Seismic Retrofit of a Cable-Stayed Bridge
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113721 Background of Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113722 Basic Concept of Seismic Retrofit
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113723 Modal Shape Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113724 Time-History Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113725 Soil ndash Structure Interaction Effect
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113726 Semiactive Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53191ch12
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Chapter 12 Seismic Random Vibration of Long-Span Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 121 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1211 Basic Concepts of Random Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12111 Stationary Random Process
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12112 Nonstationary Random Process
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1212 Three Methods for Structural Seismic Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12121 Response Spectrum Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12122 Time-History Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12123 Random Vibration Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 121231 Davenport Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 121232 Vanmarcke Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 12124 Comparisons of the Three Seismic-Analysis Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 122 Seismic Random-Excitation Fields
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1221 Power Spectral Density of Spatially Varying Ground Acceleration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1222 Several Coherence Models
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12221 FengndashHu Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12222 Harichandran ndashVanmarcke Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12223 LohndashYeh Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12224 OliveirandashHaondashPenzien Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12225 LucondashWong Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12226 QundashWangndashWang Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1223 Generation of Ground Acceleration Power Spectral Density Curves from Acceleration Response Spectrum Curves
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12231 Kaul Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12232 Iteration Scheme
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1224 Seismic Equations of Motion of Long-Span Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1225 Seismic Waves and Their Geometrical Expressions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 123 Pseudoexcitation Method for Structural Random Vibration Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1231 Structures Subjected to Stationary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12311 Single Stationary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12312 Multiple Stationary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1232 Structures Subjected to Nonstationary Random Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12321 Structures Subjected to Uniformly Modulated Evolutionary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 123211 Single Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 123212 Multiple Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12322 Structures Subjected to Nonuniformly Modulated Evolutionary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 123221 Single Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 123222 Multiple Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1233 Precise Integration Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12331 Precise Integration of Exponential Matrices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12332 Particular Solutions and Precise Integration Formulas for Various Forms of Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 123321 Linear Loading Form (HPD-L Form)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 123322 Sinusoidal Loading Form (HPD-S Form)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 123323 Exponentially Decaying Sinusoidal Loading Form (HPD-E Form)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 124 Long-Span Structures Subjected to Stationary Random Ground Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1241 The Solution of Equations of Motion Using the Pseudoexcitation Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1242 Numerical Comparisons with Other Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12421 Song-Hua-Jiang Suspension Bridge
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 124211 All Supports Move Uniformly
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 124212 Wave Passage Effect Is Taken into Account
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 124213 Wave-Passage Effect and Incoherence Effect Are Jointly Taken into Account
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 12422 San Joaquin Concrete Bridge
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 125 Long-Span Structures Subjected to Nonstationary Random Ground Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1251 Modulation Functions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1252 The Formulas for Nonstationary Multiexcitation Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1253 Expected Extreme Values of Nonstationary Random Processes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1254 Numerical Comparisons with the Corresponding Stationary Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 126 Conclusions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 53191ch13
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Chapter 13 Seismic Qualification of Equipment
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 131 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 132 Distribution Qualification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1321 Drive-Signal Generation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1322 Distribution Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1323 Test Procedures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 133 Seismic Qualification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1331 Stages of Seismic Qualification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1332 Test Preliminaries
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1333 Single-Frequency Testing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1334 Multifrequency Testing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1335 Generation of RRS Specifications
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 53191ch14
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Chapter 14 Human Response to Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 141 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 142 Vibration Excitations on Humans
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1421 Excitation Characteristics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 143 Human Response to Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1431 Vibration Perception
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1432 Frequency Weighting Curve
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1433 Iso-Perception Curves
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1434 Detection Threshold Curve
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 144 Regulation of Human Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1441 Acceptable Vibration Levels in Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1442 Whole-Body Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1443 HandndashArm Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
Page 6: Vibration Monitoring, Testing, and Instrumentationpreview.kingborn.net › 646000 › d1a74678d91943e5ba1d5e... · The MEMS Handbook, Second Edition MEMS: Introduction and Fundamentals

manufacturing Specific applications are found in machine tools transit vehicles impact processes

civil engineering structures construction machinery industrial processes product qualification and

quality control fluid flow systems ships and aircraft This book is a contribution towards these

efforts

Clarence W de SilvaEditor-in-Chief

Vancouver Canada

Prefacevi

53191mdash1432007mdash1850mdashVELUmdash246493mdash CRC ndash pp 1ndash15

copy 2007 by Taylor amp Francis Group LLC

Acknowledgments

I wish to express my gratitude to the authors of the chapters for their valuable and highly professional

contributions I am very grateful to Michael Slaughter Acquisitions Editor-Engineering CRC Press for

his enthusiasm and support throughout the project Editorial and production staff at CRC Press have

done an excellent job in getting this volume out in print Finally I wish to lovingly acknowledge the

patience and understanding of my family

vii

53191mdash1432007mdash1850mdashVELUmdash246493mdash CRC ndash pp 1ndash15

copy 2007 by Taylor amp Francis Group LLC

Editor-in-Chief

Dr Clarence W de Silva PEng Fellow ASME Fellow IEEE Fellow Canadian Academy of

Engineering is Professor of Mechanical Engineering at the University of British Columbia Vancouver

Canada and has occupied the NSERC-BC Packers Research Chair in Industrial Automation since 1988

He has earned PhD degrees from the Massachusetts Institute of Technology and the University of

Cambridge England De Silva has also occupied the Mobil Endowed Chair Professorship in the

Department of Electrical and Computer Engineering at the National University of Singapore He has

served as a consultant to several companies including IBM and Westinghouse in US and has led the

development of eight industrial machines and devices He is recipient of the Henry M Paynter

Outstanding Investigator Award from the Dynamic Systems and Control Division of the American

Society of Mechanical Engineers (ASME) Killam Research Prize Lifetime Achievement Award from the

World Automation Congress Outstanding Engineering Educator Award of IEEE Canada Yasundo

Takahashi Education Award of the Dynamic Systems and Control Division of ASME IEEE Third

Millennium Medal Meritorious Achievement Award of the Association of Professional Engineers of BC

and the Outstanding Contribution Award of the Systems Man and Cybernetics Society of the Institute

of Electrical and Electronics Engineers (IEEE)

He has authored 16 technical books including Sensors and Actuators Control System Instrumentation

(Taylor amp Francis CRC Press 2007) MechatronicsmdashAn Integrated Approach (Taylor amp Francis CRC

Press Boca Raton FL 2005) Soft Computing and Intelligent Systems DesignmdashTheory Tools and

Applications (with F Karry Addison Wesley New York NY 2004) VIBRATION Fundamentals and

Practice (Taylor amp Francis CRC Press 2nd edition 2006) INTELLIGENT CONTROL Fuzzy Logic

Applications (Taylor amp Francis CRC Press 1995) Control Sensors and Actuators (Prentice Hall 1989) 14

edited volumes over 170 journal papers 200 conference papers and 12 book chapters He has served on

the editorial boards of 14 international journals in particular as the Editor-in-Chief of the International

Journal of Control and Intelligent Systems Editor-in-Chief of the International Journal of Knowledge-Based

Intelligent Engineering Systems Senior Technical Editor of Measurements and Control and Regional

Editor North America of Engineering Applications of Artificial Intelligence ndash the International Journal of

Intelligent Real-Time Automation He is a Lilly Fellow at Carnegie Mellon University NASA-ASEE Fellow

Senior Fulbright Fellow at Cambridge University ASI Fellow and a Killam Fellow Research and

development activities of Professor de Silva are primarily centered in the areas of process automation

robotics mechatronics intelligent control and sensors and actuators with cash funding of about $6

million as principal investigator

ix

53191mdash1432007mdash1850mdashVELUmdash246493mdash CRC ndash pp 1ndash15

copy 2007 by Taylor amp Francis Group LLC

Contributors

xi

Kourosh DanaiUniversity of Massachusetts

Amherst Massachusetts

Clarence W de SilvaThe University of British Columbia

Vancouver British Columbia Canada

P S HeynsUniversity of Pretoria

Pretoria South Africa

S HuangNational University of Singapore

Singapore

Hirokazu IemuraKyoto University

Kyoto Japan

Sarvesh Kumar JainMadhav Institute of Technology and

Science

Madhya Pradesh India

Christian LalanneEngineering Consultant

Jalles France

TH LeeNational University of Singapore

Singapore

YP LeowSingapore Institute of Manufacturing

Technology

Singapore

SY LimSingapore Institute of Manufacturing

Technology

Singapore

Jiaohao LinDalian University of Technology

Liaoning Peoplersquos Republic of China

W LinSingapore Institute of Manufacturing

Technology

Singapore

Chris K MechefskeQueenrsquos University

Kingston Ontario Canada

Priyan MendisUniversity of Melbourne

Melbourne Victoria Australia

Tuan NgoUniversity of Melbourne

Melbourne Victoria Australia

Mulyo Harris PradonoKyoto University

Kyoto Japan

C SchefferUniversity of Stellenbosch

Pretoria South Africa

KK TanNational University of Singapore

Singapore

KZ TangNational University of Singapore

Singapore

Yahui ZhangDalian University of Technology

Liaoning Peoplersquos Republic of China

53191mdash1432007mdash1850mdashVELUmdash246493mdash CRC ndash pp 1ndash15

copy 2007 by Taylor amp Francis Group LLC

Contents

1 Vibration Instrumentation Clarence W de Silva 1-1

11 Introduction 1-1

12 Vibration Exciters 1-3

13 Control System 1-15

14 Performance Specification 1-21

15 Motion Sensors and Transducers 1-27

16 Torque Force and Other Sensors 1-50

Appendix 1A Virtual Instrumentation for Data Acquisition Analysis

and Presentation 1-73

2 Signal Conditioning and Modification Clarence W de Silva 2-1

21 Introduction 2-2

22 Amplifiers 2-2

23 Analog Filters 2-15

24 Modulators and Demodulators 2-29

25 AnalogndashDigital Conversion 2-37

26 Bridge Circuits 2-43

27 Linearizing Devices 2-49

28 Miscellaneous Signal Modification Circuitry 2-56

29 Signal Analyzers and Display Devices 2-62

3 Vibration Testing Clarence W de Silva 3-1

31 Introduction 3-1

32 Representation of a Vibration Environment 3-3

33 Pretest Procedures 3-24

34 Testing Procedures 3-37

35 Some Practical Information 3-52

4 Experimental Modal Analysis Clarence W de Silva 4-1

41 Introduction 4-1

42 Frequency-Domain Formulation 4-2

43 Experimental Model Development 4-8

44 Curve Fitting of Transfer Functions 4-10

45 Laboratory Experiments 4-18

46 Commercial EMA Systems 4-24

xiii

53191mdash1432007mdash1850mdashVELUmdash246493mdash CRC ndash pp 1ndash15

copy 2007 by Taylor amp Francis Group LLC

5 Mechanical Shock Christian Lalanne 5-1

51 Definitions 5-2

52 Description in the Time Domain 5-3

53 Shock Response Spectrum 5-4

54 Pyroshocks 5-17

55 Use of Shock Response Spectra 5-18

56 Standards 5-24

57 Damage Boundary Curve 5-26

58 Shock Machines 5-28

59 Generation of Shock Using Shakers 5-44

510 Control by a Shock Response Spectrum 5-52

511 Pyrotechnic Shock Simulation 5-58

6 Machine Condition Monitoring and Fault Diagnostics Chris K Mechefske 6-1

61 Introduction 6-2

62 Machinery Failure 6-2

63 Basic Maintenance Strategies 6-4

64 Factors Which Influence Maintenance Strategy 6-7

65 Machine Condition Monitoring 6-8

66 Transducer Selection 6-10

67 Transducer Location 6-14

68 Recording and Analysis Instrumentation 6-14

69 Display Formats and Analysis Tools 6-16

610 Fault Detection 6-21

611 Fault Diagnostics 6-25

7 Vibration-Based Tool Condition Monitoring Systems C Scheffer and PS Heyns 7-1

71 Introduction 7-1

72 Mechanics of Turning 7-2

73 Vibration Signal Recording 7-7

74 Signal Processing for Sensor-Based Tool Condition Monitoring 7-11

75 Wear ModelDecision-Making for Sensor-Based Tool Condition Monitoring 7-15

76 Conclusion 7-20

8 Fault Diagnosis of Helicopter Gearboxes Kourosh Danai 8-1

81 Introduction 8-1

82 Abnormality Scaling 8-5

83 The Structure-Based Connectionist Network 8-8

84 Sensor Location Selection 8-11

85 A Case Study 8-14

86 Conclusion 8-23

9 Vibration Suppression and Monitoring in Precision Motion Systems KK Tan

TH Lee KZ Tang S Huang SY Lim W Lin and YP Leow 9-1

91 Introduction 9-1

92 Mechanical Design to Minimize Vibration 9-2

93 Adaptive Notch Filter 9-10

94 Real-Time Vibration Analyzer 9-17

Contentsxiv

53191mdash1432007mdash1850mdashVELUmdash246493mdash CRC ndash pp 1ndash15

copy 2007 by Taylor amp Francis Group LLC

95 Practical Insights and Case Study 9-29

96 Conclusions 9-35

10 Vibration and Shock Problems of Civil Engineering Structures Priyan Mendis

and Tuan Ngo 10-1

101 Introduction 10-2

102 Earthquake-Induced Vibration of Structures 10-3

103 Dynamic Effects of Wind Loading on Structures 10-22

104 Vibrations Due to FluidndashStructure Interaction 10-33

105 Blast Loading and Blast Effects on Structures 10-34

106 Impact Loading 10-47

107 Floor Vibration 10-51

11 Seismic Base Isolation and Vibration Control Hirokazu Iemura Sarvesh Kumar Jain

and Mulyo Harris Pradono 11-1

111 Introduction 11-1

112 Seismic Base Isolation 11-4

113 Seismic Vibration Control 11-33

12 Seismic Random Vibration of Long-Span Structures Jiahao Lin and Yahui Zhang 12-1

121 Introduction 12-2

122 Seismic Random-Excitation Fields 12-11

123 Pseudoexcitation Method for Structural Random Vibration Analysis 12-16

124 Long-Span Structures Subjected to Stationary Random Ground Excitations 12-27

125 Long-Span Structures Subjected to Nonstationary Random Ground Excitations 12-34

126 Conclusions 12-39

13 Seismic Qualification of Equipment Clarence W de Silva 13-1

131 Introduction 13-1

132 Distribution Qualification 13-1

133 Seismic Qualification 13-6

14 Human Response to Vibration Clarence W de Silva 14-1

141 Introduction 14-1

142 Vibration Excitations on Humans 14-2

143 Human Response to Vibration 14-3

144 Regulation of Human Vibration 14-6

Contents xv

53191mdash1432007mdash1850mdashVELUmdash246493mdash CRC ndash pp 1ndash15

copy 2007 by Taylor amp Francis Group LLC

1Vibration

Instrumentation

Clarence W de SilvaThe University of British Columbia

11 Introduction 1-1

12 Vibration Exciters 1-3Shaker Selection dagger Dynamics of Electromagnetic Shakers

13 Control System 1-15Components of a Shaker Controller dagger Signal-Generating

Equipment

14 Performance Specification 1-21Parameters for Performance Specification dagger Linearity dagger

Instrument Ratings dagger Accuracy and Precision

15 Motion Sensors and Transducers 1-27Potentiometer dagger Variable-Inductance Transducers dagger

Mutual-Induction Proximity Sensor dagger Selfinduction

Transducers dagger Permanent-Magnet Transducers dagger

Alternating Current Permanent-Magnet Tachometer dagger

Alternating Current Induction Tachometer dagger Eddy Current

Transducers dagger Variable-Capacitance Transducers dagger

Piezoelectric Transducers

16 Torque Force and Other Sensors 1-50Strain Gage Sensors dagger Miscellaneous Sensors

Appendix 1A Virtual Instrumentation for DataAcquisition Analysis and Presentation 1-73

Summary

Devices useful in instrumenting a mechanical vibrating system are presented in this chapter Shakers whichgenerate vibration excitations are discussed and compared A variety of sensors including motion sensorsproximity sensors forcetorque sensors and other miscellaneous sensors are considered Performance specificationin the time domain and the frequency domain is addressed Rating parameters of instruments are given

11 Introduction

Measurement and associated experimental techniques play a significant role in the practice of vibration

Academic exposure to vibration instrumentation usually arises in laboratories in the context of learning

training and research In vibration practice perhaps the most important task of instrumentation is the

measurement or sensing of vibration Vibration sensing is useful in the following applications

1 Design and development of a product

2 Testing (screening) of a finished product for quality assurance

3 Qualification of a good-quality product to determine its suitability for a specific application

1-1

53191mdash522007mdash1201mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

4 Mechanical aging of a product prior to carrying out a test program

5 Exploratory testing of a product to determine its dynamic characteristics such as resonances

mode shapes and even a complete dynamic model

6 Vibration monitoring for performance evaluation

7 Control and suppression of vibration

Figure 11 indicates a procedure typical of experimental vibration highlighting the essential

instrumentation Vibrations are generated in a device the test object in response to some excitation In

some experimental procedures primarily in vibration testing (see Figure 11) the excitation signal has

to be generated in a signal generator in accordance with some requirement (specification) and applied to

the object through an exciter after amplification and conditioning In some other situations primarily in

performance monitoring and vibration control the excitations are generated as an integral part of the

operating environment of the vibrating object and may originate either within the object (eg engine

excitations in an automobile) or in the environment with which the object interacts during operation

(eg road disturbances on an automobile) Sensors are needed to measure vibrations in the test object In

particular a control sensor is used to check whether the specified excitation is applied to the object

and one or more response sensors may be used to measure the resulting vibrations at key locations of

the object

The sensor signals have to be properly conditioned for example by filtering and amplification and

modified for example through modulation demodulation and analog-to-digital conversion prior to

recording analyzing and display The purpose of the controller is to guarantee that the excitation is

correctly applied to the test object If the signal from the control sensor deviates from the required

excitation the controller modifies the signal to the exciter so as to reduce this deviation Furthermore the

controller will stabilize or limit (compress) the vibrations in the object It follows that instruments in

experimental vibration may be generally classified into the following categories

1 Signal-generating devices

2 Vibration exciters

3 Sensors and transducers

4 Signal conditioningmodifying devices

5 Signal analysis devices

6 Control devices

7 Vibration recording and display devices

AnalogDigital

Interface

DigitalSignal

RecorderAnalyzerDisplay

FilterAmplifier

FilterAmplifier

SignalGenerator

and ExciterController

Reference (Required)Signal (Specification)

PowerAmplifier

MountingFixtures

TestObject

ResponseSensor

ControlSensor

Exciter

SwivelBase

FIGURE 11 Typical instrumentation in experimental vibration

Vibration Monitoring Testing and Instrumentation1-2

53191mdash522007mdash1201mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

Note that one instrument may perform the tasks

of more than one category listed here Also more

than one instrument may be needed to carry out

tasks in a single category In the following sections

we will provide some examples of the types of

vibration instrumentation giving characteristics

operating principles and important practical

considerations Also we will describe several

experiments which can be found in a typical

vibration laboratory

An experimental vibration system generally

consists of four main subsystems

1 Test object

2 Excitation system

3 Control system

4 Signal acquisition and modification system

These are schematically shown in Figure 12 Note that various components shown in Figure 11 may

be incorporated into one of these subsystems In particular component matching hardware and object

mounting fixtures may be considered interfacing devices that are introduced through the interaction

between the main subsystems as shown in Figure 12 Some important issues of vibration testing and

instrumentation are summarized in Box 11

12 Vibration Exciters

Vibration experimentation may require an external exciter to generate the necessary vibration This is the

case in controlled experiments such as product testing where a specified level of vibration is applied to the

test object and the resulting response is monitored A variety of vibration exciters are available with

different capabilities and principles of operation

Three basic types of vibration exciters (shakers) are widely used hydraulic shakers inertial shakers

and electromagnetic shakers The operation-capability ranges of typical exciters in these three categories

are summarized in Table 11 Stroke or maximum displacement is the largest displacement the exciter

is capable of imparting onto a test object whose weight is assumed to be within its design load limit

Maximum velocity and acceleration are similarly defined Maximum force is the largest force that could

be applied by the shaker to a test object of acceptable weight (one within the design load) The values

given in Table 11 should be interpreted with caution Maximum displacement is achieved only at very

low frequencies The achievement of maximum velocity corresponds to intermediate frequencies in the

operating frequency range of the shaker Maximum acceleration and force ratings are usually achieved at

high frequencies It is not feasible for example to operate a vibration exciter at its maximum

displacement and its maximum acceleration simultaneously

Consider a loaded exciter that is executing harmonic motion Its displacement is given by

x frac14 s sin vt eth11THORN

in which s is the displacement amplitude (or stroke) Corresponding velocity and acceleration are

_x frac14 sv cos vt eth12THORN

eurox frac14 2sv2sin vt eth13THORN

SignalModification

System

TestObject

ControlSystem

VibrationExciter (Shaker)

System

FIGURE 12 Interactions between major subsystems of

an experimental vibration system

Vibration Instrumentation 1-3

53191mdash522007mdash1201mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

If the velocity amplitude is denoted by v and the acceleration amplitude by a it follows from Equation

12 and Equation 13 thatv frac14 vs eth14THORN

and

a frac14 vv eth15THORN

Box 11

VIBRATION INSTRUMENTATION

Vibration Testing Applications for Products

Design and Development Production Screening and Quality Assessment Utilization and Qualification for Special Applications

Testing Instrumentation

Exciter (excites the test object) Controller (controls the exciter for accurate excitation) Sensors and Transducers (measure excitations and responses and provide excitation error

signals to controller) Signal Conditioning (converts signals to appropriate form) Recording and Display (perform processing storage and documentation)

Exciters

Shakers

1 Electrodynamic (high bandwidth moderate power complex and multifrequency

excitations)

2 Hydraulic (moderate to high bandwidth high power complex and multifrequency

excitations)

3 Inertial (low bandwidth low power single-frequency harmonic excitations)

TransientInitial Condition

1 Hammers (impulsive bump tests)

2 Cable Release (step excitations)

3 Drop (impulsive)

Signal Conditioning

Filters Amplifiers Amplifiers ModulatorsDemodulators ADCDAC

Sensors

Motion (displacement velocity acceleration) Force (strain torque)

Vibration Monitoring Testing and Instrumentation1-4

53191mdash522007mdash1201mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

TABLE 11 Typical Operation-Capability Ranges for Various Shaker Types

Shaker Type Typical Operational Capabilities

Frequency Maximum Displacement

(Stroke)

Maximum

Velocity

Maximum

Acceleration

Maximum

Force

Excitation

Waveform

Hydraulic

(electrohydraulic)

Low

(01ndash500 Hz)

High (20 in 50 cm) Intermediate

(50 insec

125 cmsec)

Intermediate

(20 g)

High (100000 lbf

450000 N)

Average flexibility (simple

to complex and random)

Inertial

(counter-rotating mass)

Intermediate

(2ndash50 Hz)

Low (1 in 25 cm) Intermediate

(50 insec

125 cmsec)

Intermediate

(20 g)

Intermediate

(1000 lbf 4500 N)

Sinusoidal only

Electromagnetic

(electrodynamic)

High

(2ndash10000 Hz)

Low (1 in 25 cm) Intermediate

(50 insec

125 cmsec)

High (100 g) Low to intermediate

(450 lbf 2000 N)

High flexibility and accuracy

(simple to complex and

random)

VibrationInstru

mentation

1-5

53191mdash522007mdash

1201mdashSENTHILKUMARmdash246494mdash

CRCndashpp1ndash112

copy 2007 by Taylor amp Francis Group LLC

An idealized performance curve of a shaker

has a constant displacementndashamplitude region a

constant velocityndashamplitude region and a con-

stant accelerationndashamplitude region for low

intermediate and high frequencies respectively

in the operating frequency range Such an ideal

performance curve is shown in Figure 13(a) on a

frequencyndashvelocity plane Logarithmic axes are

used In practice typical shaker performance

curves would be fairly smooth yet nonlinear

curves similar to those shown in Figure 13(b)

As the mass increases the performance curve

compresses Note that the acceleration limit of a

shaker depends on the mass of the test object

(load) Full load corresponds to the heaviest object

that could be tested The ldquono loadrdquo condition

corresponds to a shaker without a test object To

standardize the performance curves they are

usually defined at the rated load of the shaker A

performance curve in the frequencyndashvelocity

plane may be converted to a curve in the

frequencyndashacceleration plane simply by increasing

the slope of the curve by a unit magnitude (ie

20 dbdecade)

Several general observations can be made from

Equation 14 and Equation 15 In the constant-

peak displacement region of the performance

curve the peak velocity increases proportionally

with the excitation frequency and the peak

acceleration increases with the square of the excitation frequency In the constant-peak velocity region

the peak displacement varies inversely with the excitation frequency and the peak acceleration increases

proportionately In the constant-peak acceleration region the peak displacement varies inversely with the

square of the excitation frequency and the peak velocity varies inversely with the excitation frequency

This further explains why rated stroke maximum velocity and maximum acceleration values are not

simultaneously realized

121 Shaker Selection

Vibration testing is accomplished by applying a specified excitation to the test package using a shaker

apparatus and monitoring the response of the test object Test excitation may be represented by its

response spectrum The test requires that the response spectrum of the actual excitation known as the

test response spectrum (TRS) envelops the response spectrum specified for the particular test known as

the required response spectrum (RRS)

A major step in the planning of any vibration testing program is the selection of a proper shaker

(exciter) system for a given test package The three specifications that are of primary importance in

selecting a shaker are the force rating the power rating and the stroke (maximum displacement) rating

Force and power ratings are particularly useful in moderate to high frequency excitations and the stroke

rating is the determining factor for low frequency excitations In this section a procedure is given to

determine conservative estimates for these parameters in a specified test for a given test package

Frequency domain considerations are used here

Stroke

Limit M

ax

Acceleration

MaxVelocity

Peak

Vel

ocity

(cm

s)

01 1 10 100

FullLoad

NoLoad

Frequency (Hz)(a)

Peak

Vel

ocity

(cm

s)

100

10

1

100

10

1

01 1 10 100

FullLoad

NoLoad

Frequency (Hz)(b)

FIGURE 13 Performance curve of a vibration exciter

in the frequencyndashvelocity plane (log) (a) ideal (b)

typical

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copy 2007 by Taylor amp Francis Group LLC

1211 Force Rating

In the frequency domain the (complex) force at the exciter (shaker) head is given by

F frac14 mHethvTHORNasethvTHORN eth16THORNin which v is the excitation frequency variable m is the total mass of the test package including

mounting fixture and attachments asethvTHORN is the Fourier spectrum of the support-location (exciter head)

acceleration and H(v) is frequency response function that takes into account the flexibility and

damping effects (dynamics) of the test package apart from its inertia In the simplified case where the

test package can be represented by a simple oscillator of natural frequency vn and damping ratio by zt

this function becomes

HethvTHORN frac14 1thorn 2jztv=vn=12 ethv=vnTHORN2 thorn 2jztv=vn eth17THORNin which j frac14 ffiffiffiffi

21p

This approximation is adequate for most practical purposes The static weight of the

test object is not included in Equation 16 Most heavy-duty shakers which are typically hydraulic

have static load support systems such as pneumatic cushion arrangements that can exactly balance the

dead load The exciter provides only the dynamic force In cases where shaker directly supports the

gravity load in the vertical test configuration Equation 16 should be modified by adding a term to

represent this weight

A common practice in vibration test applications is to specify the excitation signal by its response

spectrum This is simply the peak response of a simple oscillator expressed as a function of its natural

frequency when its support location is excited by the specified signal Clearly the damping of the simple

oscillator is an added parameter in a response spectrum specification Typical damping ratios ethzrTHORN used inresponse spectra specifications are less than 01 (or 10) It follows that an approximate relationship

between the Fourier spectrum of the support acceleration and its response spectrum is

as frac14 2jzrarethvTHORN eth18THORNThe magnitude larethvTHORNl is the response spectrumEquation 18 substituted into Equation 16 gives

F frac14 mHethvTHORN2jzrarethvTHORN eth19THORNIn view of Equation 17 for test packages having low damping the peak value of H(v) is

approximately 1=eth2jztTHORN this should be used in computing the force rating if the test package has a

resonance within the frequency range of testing On the other hand if the test package is assumed to be

rigid then HethvTHORN oslash 1 A conservative estimate for the force rating is

Fmax frac14 methzr=ztTHORNlarethvTHORNlmax eth110THORNIt should be noted that larethvTHORNlmax is the peak value of the specified (required) response spectrum (RRS)

for acceleration

1212 Power Rating

The exciter head does not develop its maximum force when driven at maximum velocity Output power

is determined by using

p frac14 Refrac12FvsethvTHORN eth111THORNin which vsethvTHORN is the Fourier spectrum of the exciter velocity and Re [ ] denotes the real part of a complex

function Note that as frac14 jvvs Substituting Equation 16 and Equation 18 into Equation 111 gives

p frac14 eth4mz2r =vTHORNRefrac12jHethvTHORNa2r ethvTHORN eth112THORNIt follows that a conservative estimate for the power rating is

pmax frac14 2methz2r =ztTHORNfrac12larethvTHORNl2=v max eth113THORN

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Representative segments of typical acceleration RRS curves have slope n as given by

a frac14 k1vn eth114THORN

It should be clear from Equation 113 that the maximum output power is given by

pmax frac14 k2v2n21 eth115THORN

This is an increasing function for n 1=2 and a decreasing function for n 1=2 It follows that the power

rating corresponds to the highest point of contact between the acceleration RRS curve and a line of slope

equal to 12 A similar relationship may be derived if velocity RRS curves (having slopes n2 1) are used

1213 Stroke Rating

From Equation 18 it should be clear that the Fourier spectrum xs of the exciter displacement time

history can be expressed as

xs frac14 2zrarethvTHORN=jv2 eth116THORNAn estimate for stroke rating is

xmax frac14 2zrfrac12larethvTHORNl=v2 max eth117THORNThis is of the form

xmax frac14 kvn22 eth118THORNIt follows that the stroke rating corresponds to the highest point of contact between the acceleration

RRS curve and a line of slope equal to two

Example 11

A test package of overall mass 100 kg is to be

subjected to dynamic excitation represented by the

acceleration RRS (at 5 damping) as shown in

Figure 14 The estimated damping of the test

package is 7 The test package is known to have a

resonance within the frequency range of the

specified test Determine the exciter specifications

for the test

Solution

From the development presented in the previous

section it is clear that the point F (or P) in

Figure 14 corresponds to the force and output

power ratings and the point S corresponds to

the stroke rating The co-ordinates of these

critical points are F P frac14 eth42 Hz 40 gTHORN and S frac14 eth08 Hz 075 gTHORN Equation 110 gives the force

rating as

Fmax frac14 100 pound eth005=007THORN pound 40 pound 981 N frac14 2803 N

Equation 113 gives the power rating as

pmax frac14 2 pound 100 pound eth0052=007THORN pound frac12eth40 pound 981THORN2=42 pound 2p watts frac14 417 W

Equation 117 gives the stroke rating as

xmax frac14 2 pound 005 pound frac12eth075 pound 98THORN=eth08 pound 2pTHORN2 m frac14 3 cm

Acc

eler

atio

n(g

)

Con

stan

t Dis

plac

emen

t

Constant Velo

city

Frequency (Hz)

S

FP

0101

10 10 100

10

10

FIGURE 14 Test excitation specified by an accelera-

tion RRS (5 damping)

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1214 Hydraulic Shakers

A typical hydraulic shaker consists of a piston-cylinder arrangement (also called a ram) a servo-valve a

fluid pump and a driving electric motor Hydraulic fluid (oil) is pressurized (typical operating pressure

4000 psi) and pumped into the cylinder through a servo-valve by means of a pump that is driven by an

electric motor (typical power 150 hp) The flow (typical rate 100 galmin) that enters the cylinder is

controlled (modulated) by the servo-valve which in effect controls the resulting piston (ram) motion

A typical servo-valve consists of a two-stage spool valve which provides a pressure difference and a

controlled (modulated) flow to the piston which sets it in motion

The servo-valve itself is moved by means of a linear torque motor which is driven by the excitation-

input signal (electrical) A primary function of the servo-valve is to provide a stabilizing feedback to the

ram In this respect the servo-valve complements the main control system of the test setup The ram is

coupled to the shaker table by means of a link with some flexibility The cylinder frame is mounted on the

support foundation with swivel joints This allows for some angular and lateral misalignment which

might be caused primarily by test-object dynamics as the table moves

Two-degree-of-freedom (Two-DoF) testing requires two independent sets of actuators and three-DoF

testing requires three independent actuator sets Each independent actuator set can consist of several

actuators operated in parallel using the same pump and the same excitation-input signal to the torque

motors

If the test table is directly supported on the vertical actuators they must withstand the total dead

weight (ie the weight of the test table the test object the mounting fixtures and the instrumentation)

This is requirement is usually prevented by providing a pressurized air cushion in the gap between the

test table and the foundation walls Air should be pressurized so as to balance the total dead weight

exactly (typical required gage pressure 3 psi)

Figure 15(a) shows the basic components of a typical hydraulic shaker The corresponding

operational block diagram is shown in Figure 15(b) It is desirable to locate the actuators in a pit in the

test laboratory so that the test tabletop is flushed with the test laboratory floor under no-load conditions

This minimizes the effort required to place the test object on the test table Otherwise the test object has

to be lifted onto the test table with a forklift Also installation of an aircushion to support the system

dead weight is difficult under these circumstances of elevated mounting

Hydraulic actuators are most suitable for heavy load testing and are widely used in industrial and civil

engineering applications They canbeoperated at very low frequencies (almost direct current [DC]) aswell

as at intermediate frequencies (see Table 11) Large displacements (stroke) are possible at low frequencies

Hydraulic shakers have the advantage of providing high flexibility of operation during the test their

capabilities include variable-force and constant-force testing and wide-band random-input testing The

velocity and acceleration capabilities of hydraulic shakers are moderate Although any general excitation-

input motion (for example sine wave sine beat wide-band random) can be used in hydraulic shakers

faithful reproduction of these signals is virtually impossible at high frequencies because of distortion and

higher-order harmonics introduced by the high noise levels that are common in hydraulic systems This

is only a minor drawback in heavy-duty intermediate-frequency applications Dynamic interactions are

reduced through feedback control

1215 Inertial Shakers

In inertial shakers or ldquomechanical excitersrdquo the force that causes the shaker-table motion is generated by

inertia forces (accelerating masses) Counter-rotating-mass inertial shakers are typical in this category

To understand their principle of operation consider two equal masses rotating in opposite directions at

the same angular speed v and in the same circle of radius r (see Figure 16) This produces a resultant

force equal to 2mv2r cos vt in a fixed direction (the direction of symmetry of the two rotating arms)

Consequently a sinusoidal force with a frequency of v and an amplitude proportional to v2 is generated

This reaction force is applied to the shaker table

Figure 17 shows a sketch of a typical counter-rotating-mass inertial shaker It consists of two identical

rods rotating at the same speed in opposite directions Each rod has a series of slots in which to

Vibration Instrumentation 1-9

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copy 2007 by Taylor amp Francis Group LLC

place weights In this manner the magnitude of

the eccentric mass can be varied to achieve various

force capabilities The rods are driven by a

variable-speed electric motor through a gear

mechanism that usually provides several speed

ratios A speed ratio is selected depending on the

required test-frequency range The whole system is

symmetrically supported on a carriage that is

directly connected to the test table The test object

is mounted on the test table The preferred

mounting configuration is horizontal so that the

excitation force is applied to the test object in a

horizontal direction In this configuration there

are no variable gravity moments (weight pounddistance to center of gravity) acting on the drive

mechanism Figure 17 shows the vertical con-

figuration In dynamic testing of large structures

the carriage can be mounted directly on the

structure at a location where the excitation force

should be applied By incorporating two pairs of

counter-rotating masses it is possible to generate

test moments as well as test forces

FIGURE 15 A typical hydraulic shaker arrangement (a) schematic diagram (b) operational block diagram

m m

2mw2r cos wt

wtw w

wt

FIGURE 16 Principle of operation of a counter-

rotating-mass inertial shaker

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copy 2007 by Taylor amp Francis Group LLC

Reaction-type shakers driven by inertia are widely used for the prototype testing of civil engineering

structures Their first application dates back to 1935 Inertial shakers are capable of producing

intermediate excitation forces The force generated is limited by the strength of the carriage frame The

frequency range of operation and the maximum velocity and acceleration capabilities are also

intermediate for inertial shakers whereas the maximum displacement capability is typically low A major

limitation of inertial shakers is that their excitation force is exclusively sinusoidal and that the force

amplitude is directly proportional to the square of the excitation frequency As a result complex and

random excitation testing constant-force testing (for example transmissibility tests and constant-force

sine-sweep tests) and flexibility to vary the force amplitude or the displacement amplitude during a test

are not generally feasible with this type of shakers Excitation frequency and amplitude can be varied

during testing however by incorporating a variable-speed drive for the motor The sinusoidal excitation

generated by inertial shakers is virtually undistorted which gives them an advantage over the other types

of shakers when used in sine-dwell and sine-sweep tests Small portable shakers with low-force capability

are available for use in on-site testing

1216 Electromagnetic Shakers

In electromagnetic shakers or ldquoelectrodynamic excitersrdquo the motion is generated using the principle of

operation of an electric motor Specifically the excitation force is produced when a variable excitation

signal (electrical) is passed through a moving coil placed in a magnetic field

The components of a commercial electromagnetic shaker are shown in Figure 18 A steady magnetic

field is generated by a stationary electromagnet that consists of field coils wound on a ferromagnetic base

that is rigidly attached to a protective shell structure The shaker head has a coil wound around it When

the excitation electrical signal is passed through this drive coil the shaker head which is supported on

flexure mounts will be set in motion The shaker head consists of the test table on which the test object

is mounted Shakers with interchangeable heads are available The choice of appropriate shaker head is

based on the geometry and mounting features of the test object The shaker head can be turned to

different angles by means of a swivel joint In this manner different directions of excitation (in biaxial

and triaxial testing) can be obtained

FIGURE 17 Sketch of a counter-rotating-mass inertial shaker

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copy 2007 by Taylor amp Francis Group LLC

122 Dynamics of Electromagnetic Shakers

Consider a single axis electromagnetic shaker (Figure 18) with a test object having a single natural

frequency of importance within the test frequency range The dynamic interactions between the shaker

and the test object give rise to two significant natural frequencies (and correspondingly two significant

resonances) These appear as peaks in the frequency response curve of the test setup Furthermore the

natural frequency (resonance) of the test package alone causes a ldquotroughrdquo or depression (antiresonance)

in the frequency response curve of the overall test setup To explain this characteristic consider the

dynamic model shown in Figure 19 The following mechanical parameters are defined for

Figure 19(a) m k and b are the mass stiffness and equivalent viscous damping constant respectively

of the test package and me ke and be are the corresponding parameters of the exciter (shaker) Also in

the equivalent electrical circuit of the shaker head as shown in Figure 19(b) the following electrical

parameters are defined Re and Le are the resistance and (leakage) inductance and kb is the back

electromotive force (back emf) of the linear motor Assuming that the gravitational forces are supported

FIGURE 18 Schematic sectional view of a typical electromagnetic shaker manufactured by Bruel and Kjaer

Denmark

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by the static deflections of the flexible elements and that the displacements are measured from the static

equilibrium position we have the following system equations

Test object meuroy frac14 2kethy2 yeTHORN2 beth_y2 _yeTHORN eth119THORNShaker head me euroye frac14 fe thorn kethy2 yeTHORN thorn beth_y2 _yeTHORN2 key 2 be _ye eth120THORN

Electrical Lediedt

thorn Reie thorn kb _ye frac14 vethtTHORN eth121THORN

The electromagnetic force fe generated in the shaker head is a result of the interaction of the magnetic

field generated by the current ie with coil of the moving shaker head and the constant magnetic field

(stator) in which the head coil is located Here we have

fe frac14 kbie eth122THORNNote that v(t) is the voltage signal that is applied by the amplifier to the shaker coil ye is the displacement

of the shaker head and y is the displacement response of the test package

It is assumed that kb has consistent electrical and mechanical units (Vmsec and NA) Usually

the electrical time constant of the shaker is quite small compared with the primarily mechanical

time constants of the shaker and the test package In such cases the Ledie=dt term in Equation 121 may

be neglected Consequently the equations from Equation 119 through Equation 122 may be

expressed in the Laplace (frequency) domain with the Laplace variable s taking the place of the derivative

d=dt as

ethms2 thorn bsthorn kTHORNy frac14 ethbsthorn kTHORNye eth123THORN

FIGURE 19 Dynamic models of an electromagnetic shaker and a flexible test package (a) mechanical model

(b) electrical model

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copy 2007 by Taylor amp Francis Group LLC

frac12mes2 thorn ethbthorn beTHORNsthorn ethkthorn keTHORN ye frac14 ethbsthorn kTHORNy thorn kb

Rev2

k2bs

Reye eth124THORN

It follows that the transfer function of the shaker head motion with respect to the excitation voltage is

given by

yevfrac14 kb

Re

DethsTHORNDdethsTHORN eth125THORN

where DethsTHORN is the characteristic function of the primary dynamics of the test object

DethsTHORN frac14 ms2 thorn bsthorn k eth126THORN

and DdethsTHORN is the characteristic function of the primary dynamic interactions between the shaker and thetest object

DcethsTHORN frac14 mmes4 thorn frac12methbe thorn bthorn boTHORN thornmeb s

3 thorn frac12methke thorn kTHORN thornmekthorn bethbe thorn boTHORN s2thorn frac12bke thorn ethbe thorn boTHORNk sthorn kke

eth127THORN

where

bo frac14 k2bRe

eth128THORN

It is clear that under low damping conditions DdethsTHORN will produce two resonances as it is fourth order in sand similarly DethsTHORN will produce one antiresonance (trough) corresponding to the resonance of the testobject Note that in the frequency domain s frac14 jv and hence the frequency response function given by

Equation 125 is in fact

yevfrac14 kb

Rb

DethjvTHORNDdethjvTHORN eth129THORN

The magnitude of this frequency response function for a typical test system is sketched in Figure 110

Note that this curve is for the ldquoopen-looprdquo case where there is no feedback from the shaker controller

In practice the shaker controller will be able

to compensate for the resonances and anti-

resonances to some degree depending on its

effectiveness

The main advantages of electromagnetic

shakers are their high frequency range of

operation their high degree of operating flexi-

bility and the high level of accuracy of the

generated shaker motion Faithful reproduction

of complex excitations is possible because of the

advanced electronics and control systems used in

this type of shakers Electromagnetic shakers are

not suitable for heavy-duty applications (large test

objects) however High test-input accelerations

are possible at high frequencies when electromag-

netic shakers are used but their displacement and

velocity capabilities are limited to low or

intermediate values (see Table 11)

100

10

1 10 100Excitation Frequency (Hz)

Antiresonance

Resonance

Shak

erD

ispl

acem

entM

agni

tude

Resonance

1000

FIGURE 110 Frequency response curve of a typical

electromagnetic shaker with a test object

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1221 Transient Exciters

Other varieties of exciters are commonly used in

transient-type vibration testing In these tests

either an impulsive force or an initial excitation is

applied to the test object and the resulting

response is monitored The excitations and the

responses are ldquotransientrdquo in this case Hammer

test drop tests and pluck tests fall into this

category For example a hammer test may be

conducted by hitting the object with an instru-

mented hammer and then measuring the response

of the object The hammer has a force sensor at its

tip as sketched in Figure 111 A piezoelectric or

strain-gage type force sensor may be used More

sophisticated hammers have impedance heads in

place of force sensors An impedance head

measures force and acceleration simultaneously

The results of a hammer test will depend on many

factors for example the dynamics of the hammer

body how firmly the hammer is held during the

impact how quickly the impact is applied and

whether there are multiple impacts

13 Control System

The two primary functions of the shaker control system in vibration testing are (1) to guarantee that the

specified excitation is applied to the test object and (2) to ensure that the dynamic stability (motion

constraints) of the test setup is preserved An operational block diagram illustrating these control

functions is given in Figure 112 The reference input to the control system represents the desired

excitation force that should be applied to the test object In the absence of any control however the force

reaching the test object will be distorted primarily because of (1) dynamic interactions and

nonlinearities of the shaker the test table the mounting fixtures the auxiliary instruments and the test

object itself (2) noise and errors in the signal generator amplifiers filters and other equipment and (3)

external loads and disturbances acting on the test object and other components (for example external

restraints aerodynamic forces friction) To compensate for these distorting factors response

measurements (displacements velocities acceleration and so on) are made at various locations in the

test setup and are used to control the system dynamics In particular the responses of the shaker the test

table and the test object are measured These responses are used to compare the actual excitation felt by

FIGURE 111 An instrumented hammer used in bump

tests or hammer tests

ExcitationInput

(Reference)

Feedback Paths

DriveSignal

ShakerResponse

TestTable

TestObject

Test ObjectResponse

Test TableResponseExciter

(Shaker)(Ram)

Controllerand

Amplifier

FIGURE 112 Operational block diagram illustrating a general shaker control system

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the test object at the shaker interface with the desired (specified) input The drive signal to the shaker is

modified depending on the error that is present

Two types of control are commonly employed in shaker apparatus simple manual control and

complex automatic control Manual control normally consists of simple open-loop trial-and-error

methods of manual adjustments (or calibration) of the control equipment to obtain a desired dynamic

response The actual response is usually monitored (on an oscilloscope or frequency analyzer screen for

example) during manual-control operations The pretest adjustments in manual control can be very

time-consuming as a result the test object might be subjected to overtesting which could produce

cumulative damage is undesirable and could defeat the test purpose Furthermore the calibration

procedure for the experimental setup must be repeated for each new test object

The disadvantages ofmanual control suggest that automatic control is desirable in complex test schemes

in which high accuracy of testing is desired The first step of automatic control involves automatic

measurement of the system response using control sensors and transducers The measurement is then fed

back into the control system which instantaneously determines the best drive signal to actuate the shaker

in order to get the desired excitation This may be done by either analog or digital methods

Primitive control systems require an accurate mathematical description of the test object This

dependency of the control system on the knowledge of test-object dynamics is clearly undesirable

Performance of a good control system should not be considerably affected by the dynamic interactions

and nonlinearities of the test object or by the nature of the excitation Proper selection of feedback signals

and control-system components can reduce such effects and will make the system robust

In the response-spectrum method of vibration testing it is customary to use displacement control at

low frequencies velocity control at intermediate frequency and acceleration control at high frequencies

This necessitates feedback of displacement velocity and acceleration responses Generally however the

most important feedback is the velocity feedback In sine-sweep tests the shaker velocity must change

steadily over the frequency band of interest In particular the velocity control must be precise near the

resonances of the test object Velocity (speed) feedback has a stabilizing effect on the dynamics which is

desirable This effect is particularly useful in ensuring stability in motion when testing is done near

resonances of lightly damped test objects On the contrary displacement (position) feedback can have a

destabilizing effect on some systems particularly when high feedback gains are used

The controller usually consists of various instruments equipment and computation hardware and

software Often the functions of the data-acquisition and processing system overlap with those of the

controller to some extent As an example consider the digital-controller of vibration testing apparatus

First the responses are measured through sensors (and transducers) filtered and amplified

(conditioned) These data channels may be passed through a multiplexer whose purpose is to select

one data channel at a time for processing Most modern data acquisition hardware does not need a

separate multiplexer to handle multiple signals The analog data are converted into digital data using

analog-to-digital converters (ADCs) The resulting sampled data are stored on a disk or as a block data in

the computer memory The reference input signal (typically a signal recorded on an FM tape) is also

sampled (if it is not already in the digital form) using an ADC and fed into the computer Digital

processing is done on the reference signal and the response data with the objective of computing the

command signal to drive the shaker The digital command signal is converted into an analog signal using

a digital-to-analog converter (DAC) and amplified (conditioned) before it is used to drive the exciter

The nature of the control components depends to a large extent on the nature and objectives of the

particular test to be conducted Some of the basic components in a shaker controller are described in

the following subsections

131 Components of a Shaker Controller

1311 Compressor

A compressor circuit is incorporated in automatic excitation control devices to control the excitation-

input level automatically The level of control depends on the feedback signal from a control sensor and

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the specified (reference) excitation signal Usually the compressor circuit is included in the excitation-

signal generator (for example in a sine generator) The control by this means may be done on the basis of

a single-frequency component (eg the fundamental frequency)

1312 Equalizer (Spectrum Shaper)

Random-signal equalizers are used to shape the spectrum of a random signal in a desired manner In

essence and equalizer consists of a bank of narrow-band filters (for example 80 filters) in parallel over

the operating frequency range By passing the signal through each filter the spectral density (or the mean

square value) of the signal in that narrow frequency band (for example each one-third-octave band) is

determined This is compared with the desired spectral level and automatic adjustment is made in that

filter in case there is an error In some systems response-spectrum analysis is made in place of power

spectral density analysis In that case the equalizer consists of a bank of simple oscillators whose

resonant frequencies are distributed over the operating frequency range of the equalizer The feedback

signal is passed through each oscillator and the peak value of its output is determined This value is

compared with the desired response spectrum value at that frequency If there is an error automatic gain

adjustment is made in the appropriate excitation signal components

Random-noise equalizers are used in conjunction with random signal generators They receive

feedback signals from the control sensors In some digital control systems there are algorithms (software)

that are used to iteratively converge the spectrum of the excitation signal felt by the test object into the

desired spectrum

1313 Tracking Filter

Many vibration tests are based on single-frequency excitations In such cases the control functions

should be performed on the basis of the amplitudes of the fundamental-frequency component of the

signal A tracking filter is simply a frequency-tuned band-pass filter It automatically tunes the center

frequency of its very narrow-band-pass filter to the frequency of a carrier signal Then when a noisy

signal is passed through the tuned filter the output of the filter will be the required fundamental

frequency component in the signal Tracking filters also are useful in obtaining amplitudendashfrequency

plots using an XndashY plotter In such cases the frequency value comes from the signal generator (sweep

oscillator) which produces the carrier signal to the tracking filter The tracking filter then determines the

corresponding amplitude of a signal that is fed into it Most tracking filters have dual channels so that two

signals can be handled (tracked) simultaneously

1314 Excitation Controller (Amplitude Servo-Monitor)

An excitation controller is typically an integral part of the signal generator It can be set so that automatic

sweep between two frequency limits can be performed at a selected sweep rate (linear or logarithmic)

More advanced excitation controllers have the capability of an automatic switch-over between constant-

displacement constant-velocity and constant-acceleration excitation-input control at specified

frequencies over the sweep frequency interval Consequently integrator circuits should be present

within the excitation controller unit to determine velocities and displacements from acceleration signals

Sometimes integration is performed by a separate unit called a vibration meter This unit also offers

the operator the capability of selecting the desired level of each signal (acceleration velocity or

displacement) There is an automatic cut-off level for large displacement values that could result from

noise in acceleration signals A compressor is also a subcomponent of the excitation controller The

complete unit is sometimes known as an amplitude servo-monitor

132 Signal-Generating Equipment

Shakers are force-generating devices that are operated using drive (excitation) signals generated from a

source The excitation-signal source is known as the signal generator Three major types of signal

generators are used in vibration testing applications (1) oscillators (2) random-signal generators and

(3) storage devices In some units oscillators and random-signal generators are combined We shall

Vibration Instrumentation 1-17

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copy 2007 by Taylor amp Francis Group LLC

discuss these two generators separately however because of their difference in function It also should be

noted that almost any digital signal (deterministic or random) can be generated by a digital computer

using a suitable computer program the signal eventually can be passed through a DAC to obtain

the corresponding analog signal These lsquodigitalrsquo signal generators along with analog sources such as

magnetic tape players (FM) are classified into the category of storage devices

The dynamic range of equipment is the ratio of the maximum and minimum output levels (expressed

in decibels) at which it is capable of operating without significant error This is an important specification

for many types of equipment particularly for signal-generating devices The output level of the signal

generator should be set to a value within its dynamic range

1321 Oscillators

Oscillators are essentially single-frequency generators Typically sine signals are generated but other

waveforms (such as rectangular and triangular pulses) are also available in most oscillators Normally

an oscillator has two modes of operation (1) sweeping up and down between two frequency limits and

(2) dwelling at a specified frequency In the sweep operation the sweep rate should be specified This can

be done either on a linear scale (Hzmin) or on a logarithmic scale (octavesmin) In the dwell operation

the frequency points (or intervals) should be specified In either case a desired signal level can be chosen

using the gain-control knob An oscillator that is operated exclusively in the sweep mode is called a sweep

oscillator

The early generation of oscillators employed variable inductor-capacitor types of electronic circuits to

generate signals oscillating at a desired frequency The oscillator is tuned to the required frequency by

varying the capacitance or inductance parameters A DC voltage is applied to energize the capacitor

and to obtain the desired oscillating voltage signal which subsequently is amplified and conditioned

Modern oscillators use operational amplifier circuits along with resistor capacitor and semiconductor

(SC) elements Also common are crystal (quartz) parallel-resonance oscillators used to generate voltage

signals accurately at a fixed frequency The circuit is activated using a DC-voltage source Other

frequencies of interest are obtained by passing this high-frequency signal through a frequency converter

The signal is then conditioned (amplified and filtered) Required shaping (for example rectangular

pulse) is obtained using a shape circuit Finally the required signal level is obtained by passing the

resulting signal through a variable-gain amplifier A block diagram of an oscillator illustrating various

stages in the generation of a periodic signal is given in Figure 113

A typical oscillator offers a choice of several (typically six) linear and logarithmic frequency ranges and

a sizable level of control capability (for example 80 dB) Upper and lower frequency limits in a sweep can

be preset on the front panel to any of the available frequency ranges Sweep-rate settings are continuously

DC Voltage

Oscillator

FrequencySpecification

FrequencyConverter

FilterAmplifier

ShaperPeriodicSignal

FrequencyCounter

Fixed-FrequencySignal

Variable-GainOutput

Amplifier

SignalSpecification

LevelSpecification

FIGURE 113 Block diagram of an oscillator-type signal generator

Vibration Monitoring Testing and Instrumentation1-18

53191mdash522007mdash1202mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

  • 53191fm
    • Vibration Monitoring Testing and Instrumentation
      • Preface
      • Acknowledgments
      • Editor-in-Chief
      • Contributors
      • Contents
      • Related Titles
          • 53191ch1
            • Table of Contents
            • Chapter 1 Vibration Instrumentation
              • Summary
              • 11 Introduction
              • 12 Vibration Exciters
                • 121 Shaker Selection
                  • 1211 Force Rating
                  • 1212 Power Rating
                  • 1213 Stroke Rating
                  • 1214 Hydraulic Shakers
                  • 1215 Inertial Shakers
                  • 1216 Electromagnetic Shakers
                    • 122 Dynamics of Electromagnetic Shakers
                      • 1221 Transient Exciters
                          • 13 Control System
                            • 131 Components of a Shaker Controller
                              • 1311 Compressor
                              • 1312 Equalizer (Spectrum Shaper)
                              • 1313 Tracking Filter
                              • 1314 Excitation Controller (Amplitude Servo-Monitor)
                                • 132 Signal-Generating Equipment
                                  • 1321 Oscillators
                                  • 1322 Random Signal Generators
                                  • 1323 Tape Players
                                  • 1324 Data Processing
                                      • 14 Performance Specification
                                        • 141 Parameters for Performance Specification
                                          • 1411 Time-Domain Specifications
                                          • 1412 Frequency-Domain Specifications
                                            • 142 Linearity
                                            • 143 Instrument Ratings
                                              • 1431 Rating Parameters
                                                • 144 Accuracy and Precision
                                                  • 15 Motion Sensors and Transducers
                                                    • 151 Potentiometer
                                                      • 1511 Potentiometer Resolution
                                                      • 1512 Optical Potentiometer
                                                        • 152 Variable-Inductance Transducers
                                                          • 1521 Mutual-Induction Transducers
                                                          • 1522 Linear-Variable Differential Transformer
                                                          • 1523 Signal Conditioning
                                                            • 153 Mutual-Induction Proximity Sensor
                                                            • 154 Selfinduction Transducers
                                                            • 155 Permanent-Magnet Transducers
                                                            • 156 Alternating Current Permanent-Magnet Tachometer
                                                            • 157 Alternating Current Induction Tachometer
                                                            • 158 Eddy Current Transducers
                                                            • 159 Variable-Capacitance Transducers
                                                              • 1591 Capacitive Displacement Sensors
                                                              • 1592 Capacitive Angular Velocity Sensor
                                                              • 1593 Capacitance Bridge Circuit
                                                                • 1510 Piezoelectric Transducers
                                                                  • 15101 Sensitivity
                                                                  • 15102 Piezoelectric Accelerometer
                                                                  • 15103 Charge Amplifier
                                                                      • 16 Torque Force and Other Sensors
                                                                        • 161 Strain Gage Sensors
                                                                          • 1611 Equations for Strain Gage Measurements
                                                                          • 1612 Bridge Sensitivity
                                                                          • 1613 The Bridge Constant
                                                                          • 1614 The Calibration Constant
                                                                          • 1615 Data Acquisition
                                                                          • 1616 Accuracy Considerations
                                                                          • 1617 Semiconductor Strain Gages
                                                                          • 1618 Force and Torque Sensors
                                                                          • 1619 Strain Gage Torque Sensors
                                                                          • 16110 Deflection Torque Sensors
                                                                          • 16111 Variable-Reluctance Torque Sensor
                                                                          • 16112 Reaction Torque Sensors
                                                                            • 162 Miscellaneous Sensors
                                                                              • 1621 Stroboscope
                                                                              • 1622 Fiber Optic Sensors and Lasers
                                                                              • 1623 Fiber-Optic Gyroscope
                                                                              • 1624 Laser Doppler Interferometer
                                                                              • 1625 Ultrasonic Sensors
                                                                              • 1626 Gyroscopic Sensors
                                                                                  • References
                                                                                  • Appendix 1A Virtual Instrumentation for Data Acquisition Analysis and Presentation
                                                                                    • Summary
                                                                                    • List of Abbreviations
                                                                                    • 1A1 Dynamic Signals
                                                                                      • 1A11 Acquiring and Simulating Dynamic Signals
                                                                                        • 1A111 Aliasing
                                                                                        • 1A112 Time Continuity
                                                                                            • 1A2 Measurement Configuration Considerations
                                                                                              • 1A21 Input Signal Considerations
                                                                                                • 1A211 Input Pseudodifferential and Differential Configuration
                                                                                                • 1A212 Gain
                                                                                                • 1A213 Input Coupling
                                                                                                • 1A214 Integrated Electronic Piezoelectric Excitation
                                                                                                • 1A215 Nyquist Frequency and Bandwidth
                                                                                                • 1A216 Analog-to-Digital Conversion
                                                                                                • 1A217 Antialias Filters
                                                                                                • 1A218 Input Filter Delay
                                                                                                • 1A219 Overload Detection
                                                                                                  • 1A22 Output Signal Considerations
                                                                                                    • 1A221 Output Pseudodifferential and Differential Configuration
                                                                                                    • 1A222 Attenuation
                                                                                                    • 1A223 Digital-to-Analog Conversion
                                                                                                    • 1A224 Anti-imaging and Interpolation Filters
                                                                                                    • 1A225 Output Filter Delay
                                                                                                        • 1A3 Scaling and Calibration
                                                                                                          • 1A31 Scaling to Engineering Units
                                                                                                          • 1A32 Performing System Calibration
                                                                                                            • 1A321 Propagation Delay Calibration
                                                                                                                • 1A4 Limit Testing Analysis
                                                                                                                  • 1A41 Limit Testing Overview
                                                                                                                  • 1A42 Using the SVT Limit Testing VI
                                                                                                                    • 1A5 Integration
                                                                                                                      • 1A51 Introduction to Integration
                                                                                                                      • 1A52 Implementing Integration
                                                                                                                        • 1A521 Challenges when Integrating Vibration Data
                                                                                                                          • 1A53 Time-Domain Integration
                                                                                                                            • 1A531 Single-Shot Acquisition and Integration
                                                                                                                            • 1A532 Continuous Acquisition and Integration
                                                                                                                              • 1A54 Frequency-Domain Integration
                                                                                                                                • 1A6 Vibration-Level Measurements
                                                                                                                                  • 1A61 Measuring the Root Mean Square Level
                                                                                                                                    • 1A611 Single-Shot Buffered Acquisition
                                                                                                                                    • 1A612 Continuous Signal Acquisition
                                                                                                                                      • 1A62 Performing a Running RMS Level Measurement
                                                                                                                                      • 1A63 Computing the Peak Level
                                                                                                                                      • 1A64 Computing the Crest Factor
                                                                                                                                        • 1A7 Frequency Analysis
                                                                                                                                          • 1A71 FFT Fundamentals
                                                                                                                                            • 1A711 Number of Samples
                                                                                                                                            • 1A712 Frequency Resolution
                                                                                                                                            • 1A713 Maximum Resolvable Frequency
                                                                                                                                            • 1A714 Minimum Resolvable Frequency
                                                                                                                                            • 1A715 Number of Spectral Lines
                                                                                                                                            • 1A716 Relationship between Time-Domain and Frequency-Domain Specifications and Parameters
                                                                                                                                              • 1A72 Increasing Frequency Resolution
                                                                                                                                                • 1A721 Zoom FFT Analysis
                                                                                                                                                • 1A722 Frequency Resolution of the Zoom FFT VIs
                                                                                                                                                • 1A723 Zoom Measurement
                                                                                                                                                • 1A724 Zoom Settings
                                                                                                                                                • 1A725 Subset Analysis
                                                                                                                                                    • 1A8 Transient Analysis
                                                                                                                                                      • 1A81 Transient Analysis with the Sound and Vibration Toolkit
                                                                                                                                                      • 1A82 Performing an STFT vs Time
                                                                                                                                                        • 1A821 Selecting the FFT Block Size
                                                                                                                                                        • 1A822 Overlapping
                                                                                                                                                        • 1A823 Using the SVT STFT vs Time VI
                                                                                                                                                          • 1A83 Performing an STFT vs Rotational Speed
                                                                                                                                                            • 1A831 Converting the Pulse Train to Rotational Speed
                                                                                                                                                            • 1A832 STFT vs RPM
                                                                                                                                                              • 1A84 Measuring a Shock Response Spectrum
                                                                                                                                                                • 1A9 Waterfall Display
                                                                                                                                                                  • 1A91 Using the Display VIs
                                                                                                                                                                    • 1A911 Initializing the Display
                                                                                                                                                                    • 1A912 Sending Data to the Display
                                                                                                                                                                    • 1A913 Waterfall Display for Frequency Analysis
                                                                                                                                                                    • 1A914 Waterfall Display for Transient Analysis
                                                                                                                                                                    • 1A915 Waterfall Display for Octave Spectra
                                                                                                                                                                        • 1A10 Swept-Sine Measurements
                                                                                                                                                                          • 1A101 Swept-Sine Overview
                                                                                                                                                                          • 1A102 Choosing Swept-Sine vs FFT Measurements
                                                                                                                                                                          • 1A103 Taking a Swept-Sine Measurement
                                                                                                                                                                          • 1A104 Swept-Sine Measurement Example
                                                                                                                                                                              • Bibliography
                                                                                                                                                                              • Related Titles
                                                                                                                                                                                  • 53191ch2
                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                    • Chapter 2 Signal Conditioning and Modification
                                                                                                                                                                                      • Summary
                                                                                                                                                                                      • 21 Introduction
                                                                                                                                                                                      • 22 Amplifiers
                                                                                                                                                                                        • 221 Operational Amplifier
                                                                                                                                                                                        • 222 Use of Feedback in Opamp
                                                                                                                                                                                        • 223 Voltage Current and Power Amplifiers
                                                                                                                                                                                          • 2231 Charge Amplifiers
                                                                                                                                                                                            • 224 Instrumentation Amplifiers
                                                                                                                                                                                              • 2241 Differential Amplifier
                                                                                                                                                                                              • 2242 Common Mode
                                                                                                                                                                                                • 225 Amplifier Performance Ratings
                                                                                                                                                                                                  • 2251 Common-Mode Rejection Ratio
                                                                                                                                                                                                    • 226 Component Interconnection
                                                                                                                                                                                                      • 2261 Impedance Characteristics
                                                                                                                                                                                                      • 2262 Cascade Connection of Devices
                                                                                                                                                                                                      • 2263 AC-Coupled Ampliers
                                                                                                                                                                                                          • 23 Analog Filters
                                                                                                                                                                                                            • 231 Passive Filters and Active Filters
                                                                                                                                                                                                              • 2311 Number of Poles
                                                                                                                                                                                                                • 232 Low-Pass Filters
                                                                                                                                                                                                                  • 2321 Low-Pass Butterworth Filter
                                                                                                                                                                                                                    • 233 High-Pass Filters
                                                                                                                                                                                                                    • 234 Band-Pass Filters
                                                                                                                                                                                                                      • 2341 Resonance-Type Band-Pass Filters
                                                                                                                                                                                                                        • 235 Band-Reject Filters
                                                                                                                                                                                                                          • 24 Modulators and Demodulators
                                                                                                                                                                                                                            • 241 Amplitude Modulation
                                                                                                                                                                                                                              • 2411 Modulation Theorem
                                                                                                                                                                                                                              • 2412 Side Frequencies and Side Bands
                                                                                                                                                                                                                                • 242 Application of Amplitude Modulation
                                                                                                                                                                                                                                  • 2421 Fault Detection and Diagnosis
                                                                                                                                                                                                                                    • 243 Demodulation
                                                                                                                                                                                                                                      • 25 Analog ndashDigital Conversion
                                                                                                                                                                                                                                        • 251 Digital-to-Analog Conversion
                                                                                                                                                                                                                                          • 2511 DAC Error Sources
                                                                                                                                                                                                                                            • 252 Analog-to-Digital Conversion
                                                                                                                                                                                                                                            • 253 Analog-to-Digital Converter Performance Characteristics
                                                                                                                                                                                                                                              • 2531 Resolution and Quantization Error
                                                                                                                                                                                                                                              • 2532 Monotonicity Nonlinearity and Offset Error
                                                                                                                                                                                                                                              • 2533 Analog-to-Digital Converter Conversion Rate
                                                                                                                                                                                                                                                • 254 Sample-and-Hold Circuitry
                                                                                                                                                                                                                                                • 255 Digital Filters
                                                                                                                                                                                                                                                  • 2551 Software Implementation and Hardware Implementation
                                                                                                                                                                                                                                                      • 26 Bridge Circuits
                                                                                                                                                                                                                                                        • 261 Wheatstone Bridge
                                                                                                                                                                                                                                                        • 262 Constant-Current Bridge
                                                                                                                                                                                                                                                        • 263 Bridge Amplifiers
                                                                                                                                                                                                                                                          • 2631 Half-Bridge Circuits
                                                                                                                                                                                                                                                            • 264 Impedance Bridges
                                                                                                                                                                                                                                                              • 2641 Owen Bridge
                                                                                                                                                                                                                                                              • 2642 Wien-Bridge Oscillator
                                                                                                                                                                                                                                                                  • 27 Linearizing Devices
                                                                                                                                                                                                                                                                    • 271 Linearization by Software
                                                                                                                                                                                                                                                                    • 272 Linearization by Hardware Logic
                                                                                                                                                                                                                                                                    • 273 Analog Linearizing Circuitry
                                                                                                                                                                                                                                                                    • 274 Offsetting Circuitry
                                                                                                                                                                                                                                                                    • 275 Proportional-Output Circuitry
                                                                                                                                                                                                                                                                      • 2751 Curve-Shaping Circuitry
                                                                                                                                                                                                                                                                          • 28 Miscellaneous Signal Modification Circuitry
                                                                                                                                                                                                                                                                            • 281 Phase Shifters
                                                                                                                                                                                                                                                                            • 282 Voltage-to-Frequency Converter
                                                                                                                                                                                                                                                                            • 283 Frequency-to-Voltage Converter
                                                                                                                                                                                                                                                                            • 284 Voltage-to-Current Converters
                                                                                                                                                                                                                                                                            • 285 Peak-Hold Circuits
                                                                                                                                                                                                                                                                              • 29 Signal Analyzers and Display Devices
                                                                                                                                                                                                                                                                                • 291 Signal Analyzers
                                                                                                                                                                                                                                                                                • 292 Oscilloscopes
                                                                                                                                                                                                                                                                                  • 2921 Triggering
                                                                                                                                                                                                                                                                                  • 2922 Lissajous Patterns
                                                                                                                                                                                                                                                                                  • 2923 Digital Oscilloscopes
                                                                                                                                                                                                                                                                                      • Bibliography
                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                          • 53191ch3
                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                            • Chapter 3 Vibration Testing
                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                              • 31 Introduction
                                                                                                                                                                                                                                                                                              • 32 Representation of a Vibration Environment
                                                                                                                                                                                                                                                                                                • 321 Test Signals
                                                                                                                                                                                                                                                                                                  • 3211 Stochastic vs Deterministic Signals
                                                                                                                                                                                                                                                                                                    • 322 Deterministic Signal Representation
                                                                                                                                                                                                                                                                                                      • 3221 Single-Frequency Signals
                                                                                                                                                                                                                                                                                                      • 3222 Sine Sweep
                                                                                                                                                                                                                                                                                                      • 3223 Sine Dwell
                                                                                                                                                                                                                                                                                                      • 3224 Decaying Sine
                                                                                                                                                                                                                                                                                                      • 3225 Sine Beat
                                                                                                                                                                                                                                                                                                      • 3226 Sine Beat with Pauses
                                                                                                                                                                                                                                                                                                      • 3227 Multifrequency Signals
                                                                                                                                                                                                                                                                                                      • 3228 Actual Excitation Records
                                                                                                                                                                                                                                                                                                      • 3229 Simulated Excitation Signals
                                                                                                                                                                                                                                                                                                        • 323 Stochastic Signal Representation
                                                                                                                                                                                                                                                                                                          • 3231 Ergodic Random Signals
                                                                                                                                                                                                                                                                                                          • 3232 Stationary Random Signals
                                                                                                                                                                                                                                                                                                          • 3233 Independent and Uncorrelated Signals
                                                                                                                                                                                                                                                                                                          • 3234 Transmission of Random Excitations
                                                                                                                                                                                                                                                                                                            • 324 Frequency-Domain Representations
                                                                                                                                                                                                                                                                                                              • 3241 Fourier Spectrum Method
                                                                                                                                                                                                                                                                                                              • 3242 Power Spectral Density Method
                                                                                                                                                                                                                                                                                                                • 325 Response Spectrum
                                                                                                                                                                                                                                                                                                                  • 3251 Displacement Velocity and Acceleration Spectra
                                                                                                                                                                                                                                                                                                                  • 3252 Response-Spectra Plotting Paper
                                                                                                                                                                                                                                                                                                                  • 3253 Zero-Period Acceleration
                                                                                                                                                                                                                                                                                                                  • 3254 Uses of Response Spectra
                                                                                                                                                                                                                                                                                                                    • 326 Comparison of Various Representations
                                                                                                                                                                                                                                                                                                                      • 33 Pretest Procedures
                                                                                                                                                                                                                                                                                                                        • 331 Purpose of Testing
                                                                                                                                                                                                                                                                                                                        • 332 Service Functions
                                                                                                                                                                                                                                                                                                                          • 3321 Active Equipment
                                                                                                                                                                                                                                                                                                                          • 3322 Passive Equipment
                                                                                                                                                                                                                                                                                                                          • 3323 Functional Testing
                                                                                                                                                                                                                                                                                                                            • 333 Information Acquisition
                                                                                                                                                                                                                                                                                                                              • 3331 Interface Details
                                                                                                                                                                                                                                                                                                                              • 3332 Effect of Neglecting Interface Dynamics
                                                                                                                                                                                                                                                                                                                              • 3333 Effects of Damping
                                                                                                                                                                                                                                                                                                                              • 3334 Effects of Inertia
                                                                                                                                                                                                                                                                                                                              • 3335 Effect of Natural Frequency
                                                                                                                                                                                                                                                                                                                              • 3336 Effect of Excitation Frequency
                                                                                                                                                                                                                                                                                                                              • 3337 Other Effects of Interface
                                                                                                                                                                                                                                                                                                                                • 334 Test-Program Planning
                                                                                                                                                                                                                                                                                                                                  • 3341 Testing of Cabinet-Mounted Equipment
                                                                                                                                                                                                                                                                                                                                    • 335 Pretest Inspection
                                                                                                                                                                                                                                                                                                                                      • 34 Testing Procedures
                                                                                                                                                                                                                                                                                                                                        • 341 Resonance Search
                                                                                                                                                                                                                                                                                                                                        • 342 Methods of Determining Frequency-Response Functions
                                                                                                                                                                                                                                                                                                                                          • 3421 Fourier Transform Method
                                                                                                                                                                                                                                                                                                                                          • 3422 Spectral Density Method
                                                                                                                                                                                                                                                                                                                                          • 3423 Harmonic Excitation Method
                                                                                                                                                                                                                                                                                                                                            • 343 Resonance-Search Test Methods
                                                                                                                                                                                                                                                                                                                                              • 3431 Hammer (Bump) Test and Drop Test
                                                                                                                                                                                                                                                                                                                                              • 3432 Pluck Test
                                                                                                                                                                                                                                                                                                                                              • 3433 Shaker Tests
                                                                                                                                                                                                                                                                                                                                                • 344 Mechanical Aging
                                                                                                                                                                                                                                                                                                                                                  • 3441 Equivalence for Mechanical Aging
                                                                                                                                                                                                                                                                                                                                                  • 3442 Excitation-Intensity Equivalence
                                                                                                                                                                                                                                                                                                                                                  • 3443 Dynamic-Excitation Equivalence
                                                                                                                                                                                                                                                                                                                                                  • 3444 Cumulative Damage Theory
                                                                                                                                                                                                                                                                                                                                                    • 345 Test-Response Spectrum Generation
                                                                                                                                                                                                                                                                                                                                                    • 346 Instrument Calibration
                                                                                                                                                                                                                                                                                                                                                    • 347 Test-Object Mounting
                                                                                                                                                                                                                                                                                                                                                    • 348 Test-Input Considerations
                                                                                                                                                                                                                                                                                                                                                      • 3481 Test Nomenclature
                                                                                                                                                                                                                                                                                                                                                      • 3482 Testing with Uncorrelated Excitations
                                                                                                                                                                                                                                                                                                                                                      • 3483 Symmetrical Rectilinear Testing
                                                                                                                                                                                                                                                                                                                                                      • 3484 Geometry vs Dynamics
                                                                                                                                                                                                                                                                                                                                                      • 3485 Some Limitations
                                                                                                                                                                                                                                                                                                                                                      • 3486 Testing Black Boxes
                                                                                                                                                                                                                                                                                                                                                      • 3487 Phasing of Excitations
                                                                                                                                                                                                                                                                                                                                                      • 3488 Testing a Gray or White Box
                                                                                                                                                                                                                                                                                                                                                      • 3489 Overtesting in Multitest Sequences
                                                                                                                                                                                                                                                                                                                                                          • 35 Some Practical Information
                                                                                                                                                                                                                                                                                                                                                            • 351 Random Vibration Test Example
                                                                                                                                                                                                                                                                                                                                                            • 352 Vibration Shakers and Control Systems
                                                                                                                                                                                                                                                                                                                                                              • Bibliography
                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                  • 53191ch4
                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                    • Chapter 4 Experimental Modal Analysis
                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                      • 41 Introduction
                                                                                                                                                                                                                                                                                                                                                                      • 42 Frequency-Domain Formulation
                                                                                                                                                                                                                                                                                                                                                                        • 421 Transfer-Function Matrix
                                                                                                                                                                                                                                                                                                                                                                        • 422 Principle of Reciprocity
                                                                                                                                                                                                                                                                                                                                                                          • 43 Experimental Model Development
                                                                                                                                                                                                                                                                                                                                                                            • 431 Extraction of the Time-Domain Model
                                                                                                                                                                                                                                                                                                                                                                              • 44 Curve Fitting of Transfer Functions
                                                                                                                                                                                                                                                                                                                                                                                • 441 Problem Identification
                                                                                                                                                                                                                                                                                                                                                                                • 442 Single- and Multi-Degree-of-Freedom Techniques
                                                                                                                                                                                                                                                                                                                                                                                • 443 Single-Degree-of-Freedom Parameter Extraction in the Frequency Domain
                                                                                                                                                                                                                                                                                                                                                                                  • 4431 Circle-Fit Method
                                                                                                                                                                                                                                                                                                                                                                                    • Case of Viscous Damping
                                                                                                                                                                                                                                                                                                                                                                                    • Case of Hysteretic Damping
                                                                                                                                                                                                                                                                                                                                                                                      • 4432 Peak-Picking Method
                                                                                                                                                                                                                                                                                                                                                                                        • 444 Multi-Degree of Freedom Curve Fitting
                                                                                                                                                                                                                                                                                                                                                                                          • 4441 Formulation of the Method
                                                                                                                                                                                                                                                                                                                                                                                            • 445 A Comment on Static Modes and Rigid-Body Modes
                                                                                                                                                                                                                                                                                                                                                                                            • 446 Residue Extraction
                                                                                                                                                                                                                                                                                                                                                                                              • 45 Laboratory Experiments
                                                                                                                                                                                                                                                                                                                                                                                                • 451 Lumped-Parameter System
                                                                                                                                                                                                                                                                                                                                                                                                  • 4511 Frequency-Domain Test
                                                                                                                                                                                                                                                                                                                                                                                                  • 4512 Time-Domain Tests
                                                                                                                                                                                                                                                                                                                                                                                                    • 452 Distributed-Parameter System
                                                                                                                                                                                                                                                                                                                                                                                                      • 46 Commercial EMA Systems
                                                                                                                                                                                                                                                                                                                                                                                                        • 461 System Configuration
                                                                                                                                                                                                                                                                                                                                                                                                          • 4611 FFT Analysis Options
                                                                                                                                                                                                                                                                                                                                                                                                          • 4612 Modal Analysis Components
                                                                                                                                                                                                                                                                                                                                                                                                              • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                  • 53191ch5
                                                                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                    • Chapter 5 Mechanical Shock
                                                                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                      • 51 Definitions
                                                                                                                                                                                                                                                                                                                                                                                                                        • 511 Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 512 Simple (or Perfect) Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 513 Half-Sine Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 514 Versed-Sine (or Haversine) Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 515 Terminal Peak Sawtooth Shock or Final Peak Sawtooth Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 516 Rectangular Shock
                                                                                                                                                                                                                                                                                                                                                                                                                          • 5161 Trapezoidal Shock
                                                                                                                                                                                                                                                                                                                                                                                                                              • 52 Description in the Time Domain
                                                                                                                                                                                                                                                                                                                                                                                                                              • 53 Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                • 531 Need
                                                                                                                                                                                                                                                                                                                                                                                                                                • 532 Shock Response Spectrum Definition
                                                                                                                                                                                                                                                                                                                                                                                                                                • 533 Response of a Linear One-Degree-of-Freedom System
                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5331 Shock Defined by a Force
                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5332 Shock Defined by an Acceleration
                                                                                                                                                                                                                                                                                                                                                                                                                                    • 534 Definitions
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5341 Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5342 Absolute Acceleration Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5343 Relative Displacement Shock Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5344 Primary Positive Shock Response Spectrum or Initial Positive Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5345 Primary (or Initial) Negative Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5346 Secondary (or Residual) Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5347 Positive (or Maximum Positive) Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5348 Negative (or Maximum Negative) Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5349 Maximax Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53410 Choice of Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                        • 535 Standardized Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5351 Definition
                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5352 Standardized Shock Response Spectra of Simple Shocks
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53521 Half-Sine Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53522 Versed Sine Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53523 Terminal Peak Sawtooth Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53524 Rectangular Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53525 Trapezoidal Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 536 Choice of Damping
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 537 Shock Response Spectra Domains
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 538 Algorithms for Calculation of the Shock Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 539 Choice of the Digitization Frequency of the Signal
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5310 Use of Shock Response Spectra for the Study of Systems with Several Degrees of Freedom
                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 54 Pyroshocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 55 Use of Shock Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 551 Severity Comparison of Several Shocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 552 Test Specification Development from Real Environment Data
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5521 Synthesis of Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5522 Nature of the Specification
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5523 Choice of Shape
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5524 Amplitude
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5525 Duration
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5526 Difficulties
                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 56 Standards
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 561 Types of Standards
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 562 Installation Conditions of Test Item
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 563 Uncertainty Factor
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 564 Bump Test
                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 57 Damage Boundary Curve
                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 571 Definition
                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 572 Analysis of Test Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 58 Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 581 Main Types
                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 582 Impact Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5821 Universal Shock-Test Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 58211 Impact Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 58212 Impulse Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 583 Shock Simulators (Programmers)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5831 Half-Sine Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58311 Shock Duration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58312 Impact Velocity
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58313 Maximum Deformation of the Shock Simulator (Programmer)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58314 Shock Amplitude
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58315 Characteristics of the Target
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5832 Terminal Peak Sawtooth Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5833 Rectangular Pulse ndash Trapezoidal Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5834 Universal Shock Simulator (Programmer)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 58341 Generating a Half-Sine Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 58342 Generating a Terminal Peak Sawtooth Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 58343 Trapezoidal Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 584 Limitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5841 Limitations of the Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5842 Limitations of Shock Simulators
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 585 Pneumatic Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 586 High Impact Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5861 Lightweight High Impact Shock Machine
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5862 Medium Weight High Impact Shock Machine
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 587 Specific Test Facilities
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 59 Generation of Shock Using Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 591 Principle Behind the Generation of a Simple Shape Signal versus Time
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 592 Main Advantages
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 593 Pre- and Postshocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5931 Requirements
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5932 Solutions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 59321 Optimized Pre- and Postpulses
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5933 Incidence on the Shock Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 594 Limitations of Electrodynamic Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5941 Mechanical Limitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 59411 Abacuses
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5942 Electronic Limitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 595 The Use of Electrohydraulic Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 510 Control by a Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 5101 Principle
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 5102 Principal Shapes of Elementary Signals
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 51021 Decaying Sinusoid
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 51022 ZERD Function
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 51023 WAVSIN Waveform
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 5103 Comparison of WAVSIN SHOC Waveforms and Decaying Sinusoid
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 5104 Criticism of Control by a Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 511 Pyrotechnic Shock Simulation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5111 Simulation Using Pyrotechnic Facilities
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5112 Simulation Using Metal-to-Metal Impact
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5113 Simulation Using Electrodynamic Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5114 Simulation Using Conventional Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53191ch6
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Chapter 6 Machine Condition Monitoring and Fault Diagnostics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 61 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 62 Machinery Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 621 Causes of Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 622 Types of Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 623 Frequency of Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 63 Basic Maintenance Strategies
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 631 Run-to-Failure (Breakdown) Maintenance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 632 Scheduled (Preventative) Maintenance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 633 Condition-Based (Predictive Proactive Reliability Centered On-Condition) Maintenance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 64 Factors Which Influence Maintenance Strategy
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 65 Machine Condition Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 651 Periodic Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 652 Continuous Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 66 Transducer Selection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 661 Noncontact Displacement Transducers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 662 Velocity Transducers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 663 Acceleration Transducers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 67 Transducer Location
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 68 Recording and Analysis Instrumentation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 681 Vibration Meters
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 682 Data Collectors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 683 Frequency-Domain Analyzers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 684 Time-Domain Instruments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 685 Tracking Analyzers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 69 Display Formats and Analysis Tools
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 691 Time Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6911 Time-Waveform Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6912 Time-Waveform Indices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6913 Time-Synchronous Averaging
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6914 Negative Averaging
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6915 Orbits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6916 Probability Density Functions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6917 Probability Density Moments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 692 Frequency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6921 Band-Pass Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6922 Shock Pulse (Spike Energy)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6923 Enveloped Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6924 Signature Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6925 Cascades (Waterfall Plots)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6926 Masks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6927 Frequency-Domain Indices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 693 Modal Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 694 Quefrency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 610 Fault Detection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 6101 Standards
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61011 Standards Based on Machinery Type
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61012 Standards Based on Vibration Severity
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 6102 Acceptance Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 61021 Statistical Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 6103 Frequency-Domain Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61031 Limited Band Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61032 Constant Bandwidth Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61033 Constant Percentage Bandwidth Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 611 Fault Diagnostics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 6111 Forcing Functions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61111 Unbalance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61112 Misalignment
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61113 Mechanical Looseness
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61114 Soft Foot
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61115 Rubs
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61116 Resonances
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61117 Oil Whirl
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61118 Oil Whip
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61119 Structural Vibrations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 611110 Foundation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 6112 Specific Machine Components
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 61121 Damaged or Worn Rolling-Element Bearings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 61122 Damaged or Worn Gears
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 6113 Specific Machine Types
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61131 Pumps
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61132 Fans
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61133 Electric Motors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61134 Steam and Gas Turbines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61135 Compressors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61136 Reciprocating Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 6114 Advanced Fault Diagnostic Techniques
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 53191ch7
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • Chapter 7 Vibration-Based Tool Condition Monitoring Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 71 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 72 Mechanics of Turning
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 721 General Terms
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 722 Chatter Vibrations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 723 Tool Wear
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7231 Tool Failure Mechanisms
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7232 Tool Failure Modes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7233 Tool Wear Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7234 Tool Wear Stages
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 73 Vibration Signal Recording
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 731 Direct and Indirect Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 732 Sensor Requirements for Tool Wear Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 733 Force Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7331 Direct Measurement Dynamometers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7332 Indirect Force Sensors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7333 Piezoelectric Strain Sensors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7334 Resistance Strain Gauges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7335 Customized Force Sensors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 734 Acceleration Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 735 Acoustic Emission Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 736 Sensor Comparisons
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 74 Signal Processing for Sensor-Based Tool Condition Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 741 Feature Extraction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7411 Time Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7412 Frequency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7413 Statistical Processing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7414 TimendashFrequency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 742 Feature Selection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 75 Wear ModelDecision-Making for Sensor-Based Tool Condition Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 751 Trending Threshold
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 752 Neural Networks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7521 Unsupervised Networks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7522 Supervised Networks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 753 Fuzzy Logic
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 754 Other Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 76 Conclusion
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53191ch8
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Chapter 8 Fault Diagnosis of Helicopter Gearboxes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 81 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 82 Abnormality Scaling
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 83 The Structure-Based Connectionist Network
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 84 Sensor Location Selection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 841 Coverage Index
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 842 Overlap Index
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 843 Monitoring Effectiveness
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 85 A Case Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 851 Structural and Featural Influences
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 852 Evaluation of Influences
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 853 Fault Detection Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 854 Fault Diagnostic Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 8541 Faulty Subsystem Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 8542 Faulty Component Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 855 Sensor Location Evaluation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 856 Sensor Location Validation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 86 Conclusion
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 53191ch9
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Chapter 9 Vibration Suppression and Monitoring in Precision Motion Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 91 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 92 Mechanical Design to Minimize Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 921 Stability and Static Determinacy of Machine Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 922 Two-Dimensional Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 923 Three-Dimensional Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 93 Adaptive Notch Filter
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 931 Fast Fourier Transform
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 932 Simulation and Experiments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 94 Real-Time Vibration Analyzer
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 941 Learning Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 942 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 943 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 944 Experiments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 9441 Input Variables mdash the Evaluation Criteria
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 94411 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 94412 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 9442 Evaluation Rules
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 94421 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 94422 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 9443 Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 94431 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 94432 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 95 Practical Insights and Case Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 96 Conclusions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 53191ch10
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Chapter 10 Vibration and Shock Problems of Civil Engineering Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 101 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 102 Earthquake-Induced Vibration of Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1021 Seismicity and Ground Motions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1022 Influence of Local Site Conditions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1023 Response of Structures to Ground Motions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1024 Dynamic Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10241 Equations of Motion for Linear Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10242 Equations of Motion for Linear Multiple-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1025 Earthquake Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10251 Elastic Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10252 Smoothed Design Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10253 Ductility-Modified Response Spectrum Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1026 Design Philosophy and the Code Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10261 Performance-Based Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1027 Analysis Options for Earthquake Effects
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10271 Dynamic Time History Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10272 Response Spectrum Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 102721 Response Spectrum Analysis of Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 102722 Response Spectrum Analysis of Multi-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10273 Equivalent Static Analysis (Force-Based Approach)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10274 Displacement-Based Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1028 SoilndashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1029 Active and Passive Control Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 10210 Worked Examples
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 103 Dynamic Effects of Wind Loading on Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1031 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1032 Wind Speed
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1033 Design Structures for Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10331 Types of Wind Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10332 Design Criteria
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10333 Static Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1034 Along and Across-Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10341 Along-Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10342 Across-Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1035 Wind Tunnel Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1036 Comfort Criteria Human Response to Building Motion
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1037 Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1038 Comparison with Earthquake Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 104 Vibrations Due to Fluid ndashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1041 Added Mass and Inertial Coupling
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1042 Wave-Induced Vibration of Structure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 105 Blast Loading and Blast Effects on Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1051 Explosions and Blast Phenomenon
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1052 Explosive Air-Blast Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10521 Blast Wave Scaling Laws
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10522 Prediction of Blast Pressure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1053 Gas Explosion Loading and Effect of Internal Explosions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1054 Structural Response to Blast Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10541 Elastic Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10542 Elasto-Plastic Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1055 Material Behaviors at High Strain Rate
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10551 Dynamic Properties of Concrete under High Strain Rates
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10552 Dynamic Properties of Reinforcing Steel under High Strain Rates
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1056 Failure Modes of Blast-Loaded Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10561 Global Structural Behavior
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10562 Localized Structural Behavior
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10563 PressurendashImpulse ( PndashI ) Diagrams
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1057 Blast WavendashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1058 Effect of Ground Shocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10581 Loads from Air-Induced Ground Shock
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10582 Loads from Direct Ground Shock
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1059 Technical Design Manuals for Blast-Resistant Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 10510 Computer Programs for Blast and Shock Effects
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 106 Impact Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1061 Structural Impact between Two Bodies mdash Hard Impact and Soft Impact
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1062 Example mdash Aircraft Impact
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 107 Floor Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1071 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1072 Types of Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10721 Walking
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10722 Rhythmic Activities
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10723 Mechanical Equipment
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10724 Analysis Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1073 Natural Frequency of Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10731 Computing the Natural Frequency
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10732 Computing Deflection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10733 Damping
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10734 Resonance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1074 Vibration Caused by Walking
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10741 Minimum Natural Frequency
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1075 Design for Rhythmic Excitation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10751 Harmonics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10752 Minimum Natural Frequency
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1076 Example mdash Vibration Analysis of a Reinforced Concrete Floor
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 53191ch11
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Chapter 11 Seismic Base Isolation and Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 111 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1111 From Ductility Design to Base Isolation and Control Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1112 The Importance of Reducing Seismic Input and Response
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 112 Seismic Base Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1121 Historical Development of Base Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1122 Basic Principle
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1123 Issues in Seismic Base Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11231 Performance Criteria
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11232 Type of Structure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11233 Site Characteristics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11234 Retrofit Issues
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11235 Design of Building Services
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11236 Expected Life of Isolator
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1124 Seismic Isolation Devices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11241 Laminated Rubber Bearings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11242 Lead Rubber Bearing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11243 Friction-Based Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11244 Other Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1125 Design of Isolation Devices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11251 High-Damping Rubber Bearing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112511 Stability against Buckling
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112512 Stability against Roll Out
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11252 Lead Rubber Bearings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112521 Design of Lead Plug
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112522 Design of Laminated Rubber Bearing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11253 Design of Friction Pendulum System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1126 Verification of Properties of Isolation Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11261 Tests for Isolation Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 112611 System Characterization Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 112612 Prototype Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 112613 Quality Control Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11262 Uniform Building Code Recommendations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112621 Units Dependent on Loading Rates
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112622 Units Dependent on Bilateral Load
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112623 System Adequacy
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1127 Analysis of Base-Isolated Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11271 Modeling of a Superstructure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11272 Modeling of Isolation System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11273 Static Analysis Procedure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11274 Dynamic Analysis Procedure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 112741 Response Spectrum Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 112742 Time-History Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11275 Software for Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1128 Experimental Methods for Isolated Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1129 Implementation of Seismic Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11291 New Construction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112911 Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112912 Bridges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11292 Seismic Retrofit
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112921 Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112922 Bridges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11293 Other Implementations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 11210 Performance during Past Earthquakes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 112101 Performance of Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 112102 Performance of Bridges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 113 Seismic Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1131 Historical Development of Seismic Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1132 Basic Principles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11321 Passive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11322 Active Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11323 Semiactive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11324 Hybrid Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11325 Categorization of Basic Principles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1133 Important Issues in Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11331 SoilndashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11332 DevicendashStructure Interaction and Time Delay
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11333 Design Guidelines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1134 Vibration-Control Devices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11341 Passive Control Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113411 Metallic Yielding Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113412 Friction Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113413 Viscoelastic Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113414 Viscous Fluid Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113415 Tuned Mass Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11342 Active Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113421 Electromagnetic Actuator
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113422 Hydraulic Actuators
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11343 Semiactive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113431 Variable-Orifice Hydraulic Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113432 Controllable Fluid Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113433 Controllable Friction Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11344 Hybrid Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1135 Control Algorithm
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11351 Active Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11352 Semiactive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113521 Common Control Schemes for Controllable Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113522 Special Control Schemes for Controllable Damper
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1136 Experimental Performance Verification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11361 Shaking Table Tests of a Flexible Structural Model with TMD AMD and ATMD
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11362 Substructure Hybrid Test
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113621 Hybrid Tests Using Hydraulic Actuator
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113622 Hybrid Tests Using Shaking Table
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113623 Hybrid Tests Using Inertia-Force-Driven Loading System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1137 Implementations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11371 Semiactive Control of Full-Scale Structures Using Variable Joint Damper System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113711 Background of Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113712 Test System Set Up
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113713 Control Algorithm
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113714 Test Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11372 Application of Structural Control Technologies to Seismic Retrofit of a Cable-Stayed Bridge
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113721 Background of Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113722 Basic Concept of Seismic Retrofit
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113723 Modal Shape Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113724 Time-History Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113725 Soil ndash Structure Interaction Effect
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113726 Semiactive Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53191ch12
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Chapter 12 Seismic Random Vibration of Long-Span Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 121 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1211 Basic Concepts of Random Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12111 Stationary Random Process
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12112 Nonstationary Random Process
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1212 Three Methods for Structural Seismic Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12121 Response Spectrum Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12122 Time-History Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12123 Random Vibration Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 121231 Davenport Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 121232 Vanmarcke Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 12124 Comparisons of the Three Seismic-Analysis Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 122 Seismic Random-Excitation Fields
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1221 Power Spectral Density of Spatially Varying Ground Acceleration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1222 Several Coherence Models
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12221 FengndashHu Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12222 Harichandran ndashVanmarcke Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12223 LohndashYeh Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12224 OliveirandashHaondashPenzien Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12225 LucondashWong Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12226 QundashWangndashWang Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1223 Generation of Ground Acceleration Power Spectral Density Curves from Acceleration Response Spectrum Curves
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12231 Kaul Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12232 Iteration Scheme
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1224 Seismic Equations of Motion of Long-Span Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1225 Seismic Waves and Their Geometrical Expressions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 123 Pseudoexcitation Method for Structural Random Vibration Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1231 Structures Subjected to Stationary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12311 Single Stationary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12312 Multiple Stationary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1232 Structures Subjected to Nonstationary Random Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12321 Structures Subjected to Uniformly Modulated Evolutionary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 123211 Single Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 123212 Multiple Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12322 Structures Subjected to Nonuniformly Modulated Evolutionary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 123221 Single Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 123222 Multiple Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1233 Precise Integration Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12331 Precise Integration of Exponential Matrices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12332 Particular Solutions and Precise Integration Formulas for Various Forms of Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 123321 Linear Loading Form (HPD-L Form)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 123322 Sinusoidal Loading Form (HPD-S Form)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 123323 Exponentially Decaying Sinusoidal Loading Form (HPD-E Form)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 124 Long-Span Structures Subjected to Stationary Random Ground Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1241 The Solution of Equations of Motion Using the Pseudoexcitation Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1242 Numerical Comparisons with Other Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12421 Song-Hua-Jiang Suspension Bridge
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 124211 All Supports Move Uniformly
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 124212 Wave Passage Effect Is Taken into Account
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 124213 Wave-Passage Effect and Incoherence Effect Are Jointly Taken into Account
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 12422 San Joaquin Concrete Bridge
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 125 Long-Span Structures Subjected to Nonstationary Random Ground Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1251 Modulation Functions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1252 The Formulas for Nonstationary Multiexcitation Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1253 Expected Extreme Values of Nonstationary Random Processes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1254 Numerical Comparisons with the Corresponding Stationary Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 126 Conclusions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 53191ch13
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Chapter 13 Seismic Qualification of Equipment
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 131 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 132 Distribution Qualification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1321 Drive-Signal Generation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1322 Distribution Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1323 Test Procedures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 133 Seismic Qualification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1331 Stages of Seismic Qualification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1332 Test Preliminaries
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1333 Single-Frequency Testing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1334 Multifrequency Testing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1335 Generation of RRS Specifications
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 53191ch14
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                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Chapter 14 Human Response to Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 141 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 142 Vibration Excitations on Humans
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1421 Excitation Characteristics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 143 Human Response to Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1431 Vibration Perception
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1432 Frequency Weighting Curve
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1433 Iso-Perception Curves
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1434 Detection Threshold Curve
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 144 Regulation of Human Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1441 Acceptable Vibration Levels in Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1442 Whole-Body Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1443 HandndashArm Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
Page 7: Vibration Monitoring, Testing, and Instrumentationpreview.kingborn.net › 646000 › d1a74678d91943e5ba1d5e... · The MEMS Handbook, Second Edition MEMS: Introduction and Fundamentals

Acknowledgments

I wish to express my gratitude to the authors of the chapters for their valuable and highly professional

contributions I am very grateful to Michael Slaughter Acquisitions Editor-Engineering CRC Press for

his enthusiasm and support throughout the project Editorial and production staff at CRC Press have

done an excellent job in getting this volume out in print Finally I wish to lovingly acknowledge the

patience and understanding of my family

vii

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copy 2007 by Taylor amp Francis Group LLC

Editor-in-Chief

Dr Clarence W de Silva PEng Fellow ASME Fellow IEEE Fellow Canadian Academy of

Engineering is Professor of Mechanical Engineering at the University of British Columbia Vancouver

Canada and has occupied the NSERC-BC Packers Research Chair in Industrial Automation since 1988

He has earned PhD degrees from the Massachusetts Institute of Technology and the University of

Cambridge England De Silva has also occupied the Mobil Endowed Chair Professorship in the

Department of Electrical and Computer Engineering at the National University of Singapore He has

served as a consultant to several companies including IBM and Westinghouse in US and has led the

development of eight industrial machines and devices He is recipient of the Henry M Paynter

Outstanding Investigator Award from the Dynamic Systems and Control Division of the American

Society of Mechanical Engineers (ASME) Killam Research Prize Lifetime Achievement Award from the

World Automation Congress Outstanding Engineering Educator Award of IEEE Canada Yasundo

Takahashi Education Award of the Dynamic Systems and Control Division of ASME IEEE Third

Millennium Medal Meritorious Achievement Award of the Association of Professional Engineers of BC

and the Outstanding Contribution Award of the Systems Man and Cybernetics Society of the Institute

of Electrical and Electronics Engineers (IEEE)

He has authored 16 technical books including Sensors and Actuators Control System Instrumentation

(Taylor amp Francis CRC Press 2007) MechatronicsmdashAn Integrated Approach (Taylor amp Francis CRC

Press Boca Raton FL 2005) Soft Computing and Intelligent Systems DesignmdashTheory Tools and

Applications (with F Karry Addison Wesley New York NY 2004) VIBRATION Fundamentals and

Practice (Taylor amp Francis CRC Press 2nd edition 2006) INTELLIGENT CONTROL Fuzzy Logic

Applications (Taylor amp Francis CRC Press 1995) Control Sensors and Actuators (Prentice Hall 1989) 14

edited volumes over 170 journal papers 200 conference papers and 12 book chapters He has served on

the editorial boards of 14 international journals in particular as the Editor-in-Chief of the International

Journal of Control and Intelligent Systems Editor-in-Chief of the International Journal of Knowledge-Based

Intelligent Engineering Systems Senior Technical Editor of Measurements and Control and Regional

Editor North America of Engineering Applications of Artificial Intelligence ndash the International Journal of

Intelligent Real-Time Automation He is a Lilly Fellow at Carnegie Mellon University NASA-ASEE Fellow

Senior Fulbright Fellow at Cambridge University ASI Fellow and a Killam Fellow Research and

development activities of Professor de Silva are primarily centered in the areas of process automation

robotics mechatronics intelligent control and sensors and actuators with cash funding of about $6

million as principal investigator

ix

53191mdash1432007mdash1850mdashVELUmdash246493mdash CRC ndash pp 1ndash15

copy 2007 by Taylor amp Francis Group LLC

Contributors

xi

Kourosh DanaiUniversity of Massachusetts

Amherst Massachusetts

Clarence W de SilvaThe University of British Columbia

Vancouver British Columbia Canada

P S HeynsUniversity of Pretoria

Pretoria South Africa

S HuangNational University of Singapore

Singapore

Hirokazu IemuraKyoto University

Kyoto Japan

Sarvesh Kumar JainMadhav Institute of Technology and

Science

Madhya Pradesh India

Christian LalanneEngineering Consultant

Jalles France

TH LeeNational University of Singapore

Singapore

YP LeowSingapore Institute of Manufacturing

Technology

Singapore

SY LimSingapore Institute of Manufacturing

Technology

Singapore

Jiaohao LinDalian University of Technology

Liaoning Peoplersquos Republic of China

W LinSingapore Institute of Manufacturing

Technology

Singapore

Chris K MechefskeQueenrsquos University

Kingston Ontario Canada

Priyan MendisUniversity of Melbourne

Melbourne Victoria Australia

Tuan NgoUniversity of Melbourne

Melbourne Victoria Australia

Mulyo Harris PradonoKyoto University

Kyoto Japan

C SchefferUniversity of Stellenbosch

Pretoria South Africa

KK TanNational University of Singapore

Singapore

KZ TangNational University of Singapore

Singapore

Yahui ZhangDalian University of Technology

Liaoning Peoplersquos Republic of China

53191mdash1432007mdash1850mdashVELUmdash246493mdash CRC ndash pp 1ndash15

copy 2007 by Taylor amp Francis Group LLC

Contents

1 Vibration Instrumentation Clarence W de Silva 1-1

11 Introduction 1-1

12 Vibration Exciters 1-3

13 Control System 1-15

14 Performance Specification 1-21

15 Motion Sensors and Transducers 1-27

16 Torque Force and Other Sensors 1-50

Appendix 1A Virtual Instrumentation for Data Acquisition Analysis

and Presentation 1-73

2 Signal Conditioning and Modification Clarence W de Silva 2-1

21 Introduction 2-2

22 Amplifiers 2-2

23 Analog Filters 2-15

24 Modulators and Demodulators 2-29

25 AnalogndashDigital Conversion 2-37

26 Bridge Circuits 2-43

27 Linearizing Devices 2-49

28 Miscellaneous Signal Modification Circuitry 2-56

29 Signal Analyzers and Display Devices 2-62

3 Vibration Testing Clarence W de Silva 3-1

31 Introduction 3-1

32 Representation of a Vibration Environment 3-3

33 Pretest Procedures 3-24

34 Testing Procedures 3-37

35 Some Practical Information 3-52

4 Experimental Modal Analysis Clarence W de Silva 4-1

41 Introduction 4-1

42 Frequency-Domain Formulation 4-2

43 Experimental Model Development 4-8

44 Curve Fitting of Transfer Functions 4-10

45 Laboratory Experiments 4-18

46 Commercial EMA Systems 4-24

xiii

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copy 2007 by Taylor amp Francis Group LLC

5 Mechanical Shock Christian Lalanne 5-1

51 Definitions 5-2

52 Description in the Time Domain 5-3

53 Shock Response Spectrum 5-4

54 Pyroshocks 5-17

55 Use of Shock Response Spectra 5-18

56 Standards 5-24

57 Damage Boundary Curve 5-26

58 Shock Machines 5-28

59 Generation of Shock Using Shakers 5-44

510 Control by a Shock Response Spectrum 5-52

511 Pyrotechnic Shock Simulation 5-58

6 Machine Condition Monitoring and Fault Diagnostics Chris K Mechefske 6-1

61 Introduction 6-2

62 Machinery Failure 6-2

63 Basic Maintenance Strategies 6-4

64 Factors Which Influence Maintenance Strategy 6-7

65 Machine Condition Monitoring 6-8

66 Transducer Selection 6-10

67 Transducer Location 6-14

68 Recording and Analysis Instrumentation 6-14

69 Display Formats and Analysis Tools 6-16

610 Fault Detection 6-21

611 Fault Diagnostics 6-25

7 Vibration-Based Tool Condition Monitoring Systems C Scheffer and PS Heyns 7-1

71 Introduction 7-1

72 Mechanics of Turning 7-2

73 Vibration Signal Recording 7-7

74 Signal Processing for Sensor-Based Tool Condition Monitoring 7-11

75 Wear ModelDecision-Making for Sensor-Based Tool Condition Monitoring 7-15

76 Conclusion 7-20

8 Fault Diagnosis of Helicopter Gearboxes Kourosh Danai 8-1

81 Introduction 8-1

82 Abnormality Scaling 8-5

83 The Structure-Based Connectionist Network 8-8

84 Sensor Location Selection 8-11

85 A Case Study 8-14

86 Conclusion 8-23

9 Vibration Suppression and Monitoring in Precision Motion Systems KK Tan

TH Lee KZ Tang S Huang SY Lim W Lin and YP Leow 9-1

91 Introduction 9-1

92 Mechanical Design to Minimize Vibration 9-2

93 Adaptive Notch Filter 9-10

94 Real-Time Vibration Analyzer 9-17

Contentsxiv

53191mdash1432007mdash1850mdashVELUmdash246493mdash CRC ndash pp 1ndash15

copy 2007 by Taylor amp Francis Group LLC

95 Practical Insights and Case Study 9-29

96 Conclusions 9-35

10 Vibration and Shock Problems of Civil Engineering Structures Priyan Mendis

and Tuan Ngo 10-1

101 Introduction 10-2

102 Earthquake-Induced Vibration of Structures 10-3

103 Dynamic Effects of Wind Loading on Structures 10-22

104 Vibrations Due to FluidndashStructure Interaction 10-33

105 Blast Loading and Blast Effects on Structures 10-34

106 Impact Loading 10-47

107 Floor Vibration 10-51

11 Seismic Base Isolation and Vibration Control Hirokazu Iemura Sarvesh Kumar Jain

and Mulyo Harris Pradono 11-1

111 Introduction 11-1

112 Seismic Base Isolation 11-4

113 Seismic Vibration Control 11-33

12 Seismic Random Vibration of Long-Span Structures Jiahao Lin and Yahui Zhang 12-1

121 Introduction 12-2

122 Seismic Random-Excitation Fields 12-11

123 Pseudoexcitation Method for Structural Random Vibration Analysis 12-16

124 Long-Span Structures Subjected to Stationary Random Ground Excitations 12-27

125 Long-Span Structures Subjected to Nonstationary Random Ground Excitations 12-34

126 Conclusions 12-39

13 Seismic Qualification of Equipment Clarence W de Silva 13-1

131 Introduction 13-1

132 Distribution Qualification 13-1

133 Seismic Qualification 13-6

14 Human Response to Vibration Clarence W de Silva 14-1

141 Introduction 14-1

142 Vibration Excitations on Humans 14-2

143 Human Response to Vibration 14-3

144 Regulation of Human Vibration 14-6

Contents xv

53191mdash1432007mdash1850mdashVELUmdash246493mdash CRC ndash pp 1ndash15

copy 2007 by Taylor amp Francis Group LLC

1Vibration

Instrumentation

Clarence W de SilvaThe University of British Columbia

11 Introduction 1-1

12 Vibration Exciters 1-3Shaker Selection dagger Dynamics of Electromagnetic Shakers

13 Control System 1-15Components of a Shaker Controller dagger Signal-Generating

Equipment

14 Performance Specification 1-21Parameters for Performance Specification dagger Linearity dagger

Instrument Ratings dagger Accuracy and Precision

15 Motion Sensors and Transducers 1-27Potentiometer dagger Variable-Inductance Transducers dagger

Mutual-Induction Proximity Sensor dagger Selfinduction

Transducers dagger Permanent-Magnet Transducers dagger

Alternating Current Permanent-Magnet Tachometer dagger

Alternating Current Induction Tachometer dagger Eddy Current

Transducers dagger Variable-Capacitance Transducers dagger

Piezoelectric Transducers

16 Torque Force and Other Sensors 1-50Strain Gage Sensors dagger Miscellaneous Sensors

Appendix 1A Virtual Instrumentation for DataAcquisition Analysis and Presentation 1-73

Summary

Devices useful in instrumenting a mechanical vibrating system are presented in this chapter Shakers whichgenerate vibration excitations are discussed and compared A variety of sensors including motion sensorsproximity sensors forcetorque sensors and other miscellaneous sensors are considered Performance specificationin the time domain and the frequency domain is addressed Rating parameters of instruments are given

11 Introduction

Measurement and associated experimental techniques play a significant role in the practice of vibration

Academic exposure to vibration instrumentation usually arises in laboratories in the context of learning

training and research In vibration practice perhaps the most important task of instrumentation is the

measurement or sensing of vibration Vibration sensing is useful in the following applications

1 Design and development of a product

2 Testing (screening) of a finished product for quality assurance

3 Qualification of a good-quality product to determine its suitability for a specific application

1-1

53191mdash522007mdash1201mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

4 Mechanical aging of a product prior to carrying out a test program

5 Exploratory testing of a product to determine its dynamic characteristics such as resonances

mode shapes and even a complete dynamic model

6 Vibration monitoring for performance evaluation

7 Control and suppression of vibration

Figure 11 indicates a procedure typical of experimental vibration highlighting the essential

instrumentation Vibrations are generated in a device the test object in response to some excitation In

some experimental procedures primarily in vibration testing (see Figure 11) the excitation signal has

to be generated in a signal generator in accordance with some requirement (specification) and applied to

the object through an exciter after amplification and conditioning In some other situations primarily in

performance monitoring and vibration control the excitations are generated as an integral part of the

operating environment of the vibrating object and may originate either within the object (eg engine

excitations in an automobile) or in the environment with which the object interacts during operation

(eg road disturbances on an automobile) Sensors are needed to measure vibrations in the test object In

particular a control sensor is used to check whether the specified excitation is applied to the object

and one or more response sensors may be used to measure the resulting vibrations at key locations of

the object

The sensor signals have to be properly conditioned for example by filtering and amplification and

modified for example through modulation demodulation and analog-to-digital conversion prior to

recording analyzing and display The purpose of the controller is to guarantee that the excitation is

correctly applied to the test object If the signal from the control sensor deviates from the required

excitation the controller modifies the signal to the exciter so as to reduce this deviation Furthermore the

controller will stabilize or limit (compress) the vibrations in the object It follows that instruments in

experimental vibration may be generally classified into the following categories

1 Signal-generating devices

2 Vibration exciters

3 Sensors and transducers

4 Signal conditioningmodifying devices

5 Signal analysis devices

6 Control devices

7 Vibration recording and display devices

AnalogDigital

Interface

DigitalSignal

RecorderAnalyzerDisplay

FilterAmplifier

FilterAmplifier

SignalGenerator

and ExciterController

Reference (Required)Signal (Specification)

PowerAmplifier

MountingFixtures

TestObject

ResponseSensor

ControlSensor

Exciter

SwivelBase

FIGURE 11 Typical instrumentation in experimental vibration

Vibration Monitoring Testing and Instrumentation1-2

53191mdash522007mdash1201mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

Note that one instrument may perform the tasks

of more than one category listed here Also more

than one instrument may be needed to carry out

tasks in a single category In the following sections

we will provide some examples of the types of

vibration instrumentation giving characteristics

operating principles and important practical

considerations Also we will describe several

experiments which can be found in a typical

vibration laboratory

An experimental vibration system generally

consists of four main subsystems

1 Test object

2 Excitation system

3 Control system

4 Signal acquisition and modification system

These are schematically shown in Figure 12 Note that various components shown in Figure 11 may

be incorporated into one of these subsystems In particular component matching hardware and object

mounting fixtures may be considered interfacing devices that are introduced through the interaction

between the main subsystems as shown in Figure 12 Some important issues of vibration testing and

instrumentation are summarized in Box 11

12 Vibration Exciters

Vibration experimentation may require an external exciter to generate the necessary vibration This is the

case in controlled experiments such as product testing where a specified level of vibration is applied to the

test object and the resulting response is monitored A variety of vibration exciters are available with

different capabilities and principles of operation

Three basic types of vibration exciters (shakers) are widely used hydraulic shakers inertial shakers

and electromagnetic shakers The operation-capability ranges of typical exciters in these three categories

are summarized in Table 11 Stroke or maximum displacement is the largest displacement the exciter

is capable of imparting onto a test object whose weight is assumed to be within its design load limit

Maximum velocity and acceleration are similarly defined Maximum force is the largest force that could

be applied by the shaker to a test object of acceptable weight (one within the design load) The values

given in Table 11 should be interpreted with caution Maximum displacement is achieved only at very

low frequencies The achievement of maximum velocity corresponds to intermediate frequencies in the

operating frequency range of the shaker Maximum acceleration and force ratings are usually achieved at

high frequencies It is not feasible for example to operate a vibration exciter at its maximum

displacement and its maximum acceleration simultaneously

Consider a loaded exciter that is executing harmonic motion Its displacement is given by

x frac14 s sin vt eth11THORN

in which s is the displacement amplitude (or stroke) Corresponding velocity and acceleration are

_x frac14 sv cos vt eth12THORN

eurox frac14 2sv2sin vt eth13THORN

SignalModification

System

TestObject

ControlSystem

VibrationExciter (Shaker)

System

FIGURE 12 Interactions between major subsystems of

an experimental vibration system

Vibration Instrumentation 1-3

53191mdash522007mdash1201mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

If the velocity amplitude is denoted by v and the acceleration amplitude by a it follows from Equation

12 and Equation 13 thatv frac14 vs eth14THORN

and

a frac14 vv eth15THORN

Box 11

VIBRATION INSTRUMENTATION

Vibration Testing Applications for Products

Design and Development Production Screening and Quality Assessment Utilization and Qualification for Special Applications

Testing Instrumentation

Exciter (excites the test object) Controller (controls the exciter for accurate excitation) Sensors and Transducers (measure excitations and responses and provide excitation error

signals to controller) Signal Conditioning (converts signals to appropriate form) Recording and Display (perform processing storage and documentation)

Exciters

Shakers

1 Electrodynamic (high bandwidth moderate power complex and multifrequency

excitations)

2 Hydraulic (moderate to high bandwidth high power complex and multifrequency

excitations)

3 Inertial (low bandwidth low power single-frequency harmonic excitations)

TransientInitial Condition

1 Hammers (impulsive bump tests)

2 Cable Release (step excitations)

3 Drop (impulsive)

Signal Conditioning

Filters Amplifiers Amplifiers ModulatorsDemodulators ADCDAC

Sensors

Motion (displacement velocity acceleration) Force (strain torque)

Vibration Monitoring Testing and Instrumentation1-4

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copy 2007 by Taylor amp Francis Group LLC

TABLE 11 Typical Operation-Capability Ranges for Various Shaker Types

Shaker Type Typical Operational Capabilities

Frequency Maximum Displacement

(Stroke)

Maximum

Velocity

Maximum

Acceleration

Maximum

Force

Excitation

Waveform

Hydraulic

(electrohydraulic)

Low

(01ndash500 Hz)

High (20 in 50 cm) Intermediate

(50 insec

125 cmsec)

Intermediate

(20 g)

High (100000 lbf

450000 N)

Average flexibility (simple

to complex and random)

Inertial

(counter-rotating mass)

Intermediate

(2ndash50 Hz)

Low (1 in 25 cm) Intermediate

(50 insec

125 cmsec)

Intermediate

(20 g)

Intermediate

(1000 lbf 4500 N)

Sinusoidal only

Electromagnetic

(electrodynamic)

High

(2ndash10000 Hz)

Low (1 in 25 cm) Intermediate

(50 insec

125 cmsec)

High (100 g) Low to intermediate

(450 lbf 2000 N)

High flexibility and accuracy

(simple to complex and

random)

VibrationInstru

mentation

1-5

53191mdash522007mdash

1201mdashSENTHILKUMARmdash246494mdash

CRCndashpp1ndash112

copy 2007 by Taylor amp Francis Group LLC

An idealized performance curve of a shaker

has a constant displacementndashamplitude region a

constant velocityndashamplitude region and a con-

stant accelerationndashamplitude region for low

intermediate and high frequencies respectively

in the operating frequency range Such an ideal

performance curve is shown in Figure 13(a) on a

frequencyndashvelocity plane Logarithmic axes are

used In practice typical shaker performance

curves would be fairly smooth yet nonlinear

curves similar to those shown in Figure 13(b)

As the mass increases the performance curve

compresses Note that the acceleration limit of a

shaker depends on the mass of the test object

(load) Full load corresponds to the heaviest object

that could be tested The ldquono loadrdquo condition

corresponds to a shaker without a test object To

standardize the performance curves they are

usually defined at the rated load of the shaker A

performance curve in the frequencyndashvelocity

plane may be converted to a curve in the

frequencyndashacceleration plane simply by increasing

the slope of the curve by a unit magnitude (ie

20 dbdecade)

Several general observations can be made from

Equation 14 and Equation 15 In the constant-

peak displacement region of the performance

curve the peak velocity increases proportionally

with the excitation frequency and the peak

acceleration increases with the square of the excitation frequency In the constant-peak velocity region

the peak displacement varies inversely with the excitation frequency and the peak acceleration increases

proportionately In the constant-peak acceleration region the peak displacement varies inversely with the

square of the excitation frequency and the peak velocity varies inversely with the excitation frequency

This further explains why rated stroke maximum velocity and maximum acceleration values are not

simultaneously realized

121 Shaker Selection

Vibration testing is accomplished by applying a specified excitation to the test package using a shaker

apparatus and monitoring the response of the test object Test excitation may be represented by its

response spectrum The test requires that the response spectrum of the actual excitation known as the

test response spectrum (TRS) envelops the response spectrum specified for the particular test known as

the required response spectrum (RRS)

A major step in the planning of any vibration testing program is the selection of a proper shaker

(exciter) system for a given test package The three specifications that are of primary importance in

selecting a shaker are the force rating the power rating and the stroke (maximum displacement) rating

Force and power ratings are particularly useful in moderate to high frequency excitations and the stroke

rating is the determining factor for low frequency excitations In this section a procedure is given to

determine conservative estimates for these parameters in a specified test for a given test package

Frequency domain considerations are used here

Stroke

Limit M

ax

Acceleration

MaxVelocity

Peak

Vel

ocity

(cm

s)

01 1 10 100

FullLoad

NoLoad

Frequency (Hz)(a)

Peak

Vel

ocity

(cm

s)

100

10

1

100

10

1

01 1 10 100

FullLoad

NoLoad

Frequency (Hz)(b)

FIGURE 13 Performance curve of a vibration exciter

in the frequencyndashvelocity plane (log) (a) ideal (b)

typical

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copy 2007 by Taylor amp Francis Group LLC

1211 Force Rating

In the frequency domain the (complex) force at the exciter (shaker) head is given by

F frac14 mHethvTHORNasethvTHORN eth16THORNin which v is the excitation frequency variable m is the total mass of the test package including

mounting fixture and attachments asethvTHORN is the Fourier spectrum of the support-location (exciter head)

acceleration and H(v) is frequency response function that takes into account the flexibility and

damping effects (dynamics) of the test package apart from its inertia In the simplified case where the

test package can be represented by a simple oscillator of natural frequency vn and damping ratio by zt

this function becomes

HethvTHORN frac14 1thorn 2jztv=vn=12 ethv=vnTHORN2 thorn 2jztv=vn eth17THORNin which j frac14 ffiffiffiffi

21p

This approximation is adequate for most practical purposes The static weight of the

test object is not included in Equation 16 Most heavy-duty shakers which are typically hydraulic

have static load support systems such as pneumatic cushion arrangements that can exactly balance the

dead load The exciter provides only the dynamic force In cases where shaker directly supports the

gravity load in the vertical test configuration Equation 16 should be modified by adding a term to

represent this weight

A common practice in vibration test applications is to specify the excitation signal by its response

spectrum This is simply the peak response of a simple oscillator expressed as a function of its natural

frequency when its support location is excited by the specified signal Clearly the damping of the simple

oscillator is an added parameter in a response spectrum specification Typical damping ratios ethzrTHORN used inresponse spectra specifications are less than 01 (or 10) It follows that an approximate relationship

between the Fourier spectrum of the support acceleration and its response spectrum is

as frac14 2jzrarethvTHORN eth18THORNThe magnitude larethvTHORNl is the response spectrumEquation 18 substituted into Equation 16 gives

F frac14 mHethvTHORN2jzrarethvTHORN eth19THORNIn view of Equation 17 for test packages having low damping the peak value of H(v) is

approximately 1=eth2jztTHORN this should be used in computing the force rating if the test package has a

resonance within the frequency range of testing On the other hand if the test package is assumed to be

rigid then HethvTHORN oslash 1 A conservative estimate for the force rating is

Fmax frac14 methzr=ztTHORNlarethvTHORNlmax eth110THORNIt should be noted that larethvTHORNlmax is the peak value of the specified (required) response spectrum (RRS)

for acceleration

1212 Power Rating

The exciter head does not develop its maximum force when driven at maximum velocity Output power

is determined by using

p frac14 Refrac12FvsethvTHORN eth111THORNin which vsethvTHORN is the Fourier spectrum of the exciter velocity and Re [ ] denotes the real part of a complex

function Note that as frac14 jvvs Substituting Equation 16 and Equation 18 into Equation 111 gives

p frac14 eth4mz2r =vTHORNRefrac12jHethvTHORNa2r ethvTHORN eth112THORNIt follows that a conservative estimate for the power rating is

pmax frac14 2methz2r =ztTHORNfrac12larethvTHORNl2=v max eth113THORN

Vibration Instrumentation 1-7

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copy 2007 by Taylor amp Francis Group LLC

Representative segments of typical acceleration RRS curves have slope n as given by

a frac14 k1vn eth114THORN

It should be clear from Equation 113 that the maximum output power is given by

pmax frac14 k2v2n21 eth115THORN

This is an increasing function for n 1=2 and a decreasing function for n 1=2 It follows that the power

rating corresponds to the highest point of contact between the acceleration RRS curve and a line of slope

equal to 12 A similar relationship may be derived if velocity RRS curves (having slopes n2 1) are used

1213 Stroke Rating

From Equation 18 it should be clear that the Fourier spectrum xs of the exciter displacement time

history can be expressed as

xs frac14 2zrarethvTHORN=jv2 eth116THORNAn estimate for stroke rating is

xmax frac14 2zrfrac12larethvTHORNl=v2 max eth117THORNThis is of the form

xmax frac14 kvn22 eth118THORNIt follows that the stroke rating corresponds to the highest point of contact between the acceleration

RRS curve and a line of slope equal to two

Example 11

A test package of overall mass 100 kg is to be

subjected to dynamic excitation represented by the

acceleration RRS (at 5 damping) as shown in

Figure 14 The estimated damping of the test

package is 7 The test package is known to have a

resonance within the frequency range of the

specified test Determine the exciter specifications

for the test

Solution

From the development presented in the previous

section it is clear that the point F (or P) in

Figure 14 corresponds to the force and output

power ratings and the point S corresponds to

the stroke rating The co-ordinates of these

critical points are F P frac14 eth42 Hz 40 gTHORN and S frac14 eth08 Hz 075 gTHORN Equation 110 gives the force

rating as

Fmax frac14 100 pound eth005=007THORN pound 40 pound 981 N frac14 2803 N

Equation 113 gives the power rating as

pmax frac14 2 pound 100 pound eth0052=007THORN pound frac12eth40 pound 981THORN2=42 pound 2p watts frac14 417 W

Equation 117 gives the stroke rating as

xmax frac14 2 pound 005 pound frac12eth075 pound 98THORN=eth08 pound 2pTHORN2 m frac14 3 cm

Acc

eler

atio

n(g

)

Con

stan

t Dis

plac

emen

t

Constant Velo

city

Frequency (Hz)

S

FP

0101

10 10 100

10

10

FIGURE 14 Test excitation specified by an accelera-

tion RRS (5 damping)

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1214 Hydraulic Shakers

A typical hydraulic shaker consists of a piston-cylinder arrangement (also called a ram) a servo-valve a

fluid pump and a driving electric motor Hydraulic fluid (oil) is pressurized (typical operating pressure

4000 psi) and pumped into the cylinder through a servo-valve by means of a pump that is driven by an

electric motor (typical power 150 hp) The flow (typical rate 100 galmin) that enters the cylinder is

controlled (modulated) by the servo-valve which in effect controls the resulting piston (ram) motion

A typical servo-valve consists of a two-stage spool valve which provides a pressure difference and a

controlled (modulated) flow to the piston which sets it in motion

The servo-valve itself is moved by means of a linear torque motor which is driven by the excitation-

input signal (electrical) A primary function of the servo-valve is to provide a stabilizing feedback to the

ram In this respect the servo-valve complements the main control system of the test setup The ram is

coupled to the shaker table by means of a link with some flexibility The cylinder frame is mounted on the

support foundation with swivel joints This allows for some angular and lateral misalignment which

might be caused primarily by test-object dynamics as the table moves

Two-degree-of-freedom (Two-DoF) testing requires two independent sets of actuators and three-DoF

testing requires three independent actuator sets Each independent actuator set can consist of several

actuators operated in parallel using the same pump and the same excitation-input signal to the torque

motors

If the test table is directly supported on the vertical actuators they must withstand the total dead

weight (ie the weight of the test table the test object the mounting fixtures and the instrumentation)

This is requirement is usually prevented by providing a pressurized air cushion in the gap between the

test table and the foundation walls Air should be pressurized so as to balance the total dead weight

exactly (typical required gage pressure 3 psi)

Figure 15(a) shows the basic components of a typical hydraulic shaker The corresponding

operational block diagram is shown in Figure 15(b) It is desirable to locate the actuators in a pit in the

test laboratory so that the test tabletop is flushed with the test laboratory floor under no-load conditions

This minimizes the effort required to place the test object on the test table Otherwise the test object has

to be lifted onto the test table with a forklift Also installation of an aircushion to support the system

dead weight is difficult under these circumstances of elevated mounting

Hydraulic actuators are most suitable for heavy load testing and are widely used in industrial and civil

engineering applications They canbeoperated at very low frequencies (almost direct current [DC]) aswell

as at intermediate frequencies (see Table 11) Large displacements (stroke) are possible at low frequencies

Hydraulic shakers have the advantage of providing high flexibility of operation during the test their

capabilities include variable-force and constant-force testing and wide-band random-input testing The

velocity and acceleration capabilities of hydraulic shakers are moderate Although any general excitation-

input motion (for example sine wave sine beat wide-band random) can be used in hydraulic shakers

faithful reproduction of these signals is virtually impossible at high frequencies because of distortion and

higher-order harmonics introduced by the high noise levels that are common in hydraulic systems This

is only a minor drawback in heavy-duty intermediate-frequency applications Dynamic interactions are

reduced through feedback control

1215 Inertial Shakers

In inertial shakers or ldquomechanical excitersrdquo the force that causes the shaker-table motion is generated by

inertia forces (accelerating masses) Counter-rotating-mass inertial shakers are typical in this category

To understand their principle of operation consider two equal masses rotating in opposite directions at

the same angular speed v and in the same circle of radius r (see Figure 16) This produces a resultant

force equal to 2mv2r cos vt in a fixed direction (the direction of symmetry of the two rotating arms)

Consequently a sinusoidal force with a frequency of v and an amplitude proportional to v2 is generated

This reaction force is applied to the shaker table

Figure 17 shows a sketch of a typical counter-rotating-mass inertial shaker It consists of two identical

rods rotating at the same speed in opposite directions Each rod has a series of slots in which to

Vibration Instrumentation 1-9

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copy 2007 by Taylor amp Francis Group LLC

place weights In this manner the magnitude of

the eccentric mass can be varied to achieve various

force capabilities The rods are driven by a

variable-speed electric motor through a gear

mechanism that usually provides several speed

ratios A speed ratio is selected depending on the

required test-frequency range The whole system is

symmetrically supported on a carriage that is

directly connected to the test table The test object

is mounted on the test table The preferred

mounting configuration is horizontal so that the

excitation force is applied to the test object in a

horizontal direction In this configuration there

are no variable gravity moments (weight pounddistance to center of gravity) acting on the drive

mechanism Figure 17 shows the vertical con-

figuration In dynamic testing of large structures

the carriage can be mounted directly on the

structure at a location where the excitation force

should be applied By incorporating two pairs of

counter-rotating masses it is possible to generate

test moments as well as test forces

FIGURE 15 A typical hydraulic shaker arrangement (a) schematic diagram (b) operational block diagram

m m

2mw2r cos wt

wtw w

wt

FIGURE 16 Principle of operation of a counter-

rotating-mass inertial shaker

Vibration Monitoring Testing and Instrumentation1-10

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copy 2007 by Taylor amp Francis Group LLC

Reaction-type shakers driven by inertia are widely used for the prototype testing of civil engineering

structures Their first application dates back to 1935 Inertial shakers are capable of producing

intermediate excitation forces The force generated is limited by the strength of the carriage frame The

frequency range of operation and the maximum velocity and acceleration capabilities are also

intermediate for inertial shakers whereas the maximum displacement capability is typically low A major

limitation of inertial shakers is that their excitation force is exclusively sinusoidal and that the force

amplitude is directly proportional to the square of the excitation frequency As a result complex and

random excitation testing constant-force testing (for example transmissibility tests and constant-force

sine-sweep tests) and flexibility to vary the force amplitude or the displacement amplitude during a test

are not generally feasible with this type of shakers Excitation frequency and amplitude can be varied

during testing however by incorporating a variable-speed drive for the motor The sinusoidal excitation

generated by inertial shakers is virtually undistorted which gives them an advantage over the other types

of shakers when used in sine-dwell and sine-sweep tests Small portable shakers with low-force capability

are available for use in on-site testing

1216 Electromagnetic Shakers

In electromagnetic shakers or ldquoelectrodynamic excitersrdquo the motion is generated using the principle of

operation of an electric motor Specifically the excitation force is produced when a variable excitation

signal (electrical) is passed through a moving coil placed in a magnetic field

The components of a commercial electromagnetic shaker are shown in Figure 18 A steady magnetic

field is generated by a stationary electromagnet that consists of field coils wound on a ferromagnetic base

that is rigidly attached to a protective shell structure The shaker head has a coil wound around it When

the excitation electrical signal is passed through this drive coil the shaker head which is supported on

flexure mounts will be set in motion The shaker head consists of the test table on which the test object

is mounted Shakers with interchangeable heads are available The choice of appropriate shaker head is

based on the geometry and mounting features of the test object The shaker head can be turned to

different angles by means of a swivel joint In this manner different directions of excitation (in biaxial

and triaxial testing) can be obtained

FIGURE 17 Sketch of a counter-rotating-mass inertial shaker

Vibration Instrumentation 1-11

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copy 2007 by Taylor amp Francis Group LLC

122 Dynamics of Electromagnetic Shakers

Consider a single axis electromagnetic shaker (Figure 18) with a test object having a single natural

frequency of importance within the test frequency range The dynamic interactions between the shaker

and the test object give rise to two significant natural frequencies (and correspondingly two significant

resonances) These appear as peaks in the frequency response curve of the test setup Furthermore the

natural frequency (resonance) of the test package alone causes a ldquotroughrdquo or depression (antiresonance)

in the frequency response curve of the overall test setup To explain this characteristic consider the

dynamic model shown in Figure 19 The following mechanical parameters are defined for

Figure 19(a) m k and b are the mass stiffness and equivalent viscous damping constant respectively

of the test package and me ke and be are the corresponding parameters of the exciter (shaker) Also in

the equivalent electrical circuit of the shaker head as shown in Figure 19(b) the following electrical

parameters are defined Re and Le are the resistance and (leakage) inductance and kb is the back

electromotive force (back emf) of the linear motor Assuming that the gravitational forces are supported

FIGURE 18 Schematic sectional view of a typical electromagnetic shaker manufactured by Bruel and Kjaer

Denmark

Vibration Monitoring Testing and Instrumentation1-12

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copy 2007 by Taylor amp Francis Group LLC

by the static deflections of the flexible elements and that the displacements are measured from the static

equilibrium position we have the following system equations

Test object meuroy frac14 2kethy2 yeTHORN2 beth_y2 _yeTHORN eth119THORNShaker head me euroye frac14 fe thorn kethy2 yeTHORN thorn beth_y2 _yeTHORN2 key 2 be _ye eth120THORN

Electrical Lediedt

thorn Reie thorn kb _ye frac14 vethtTHORN eth121THORN

The electromagnetic force fe generated in the shaker head is a result of the interaction of the magnetic

field generated by the current ie with coil of the moving shaker head and the constant magnetic field

(stator) in which the head coil is located Here we have

fe frac14 kbie eth122THORNNote that v(t) is the voltage signal that is applied by the amplifier to the shaker coil ye is the displacement

of the shaker head and y is the displacement response of the test package

It is assumed that kb has consistent electrical and mechanical units (Vmsec and NA) Usually

the electrical time constant of the shaker is quite small compared with the primarily mechanical

time constants of the shaker and the test package In such cases the Ledie=dt term in Equation 121 may

be neglected Consequently the equations from Equation 119 through Equation 122 may be

expressed in the Laplace (frequency) domain with the Laplace variable s taking the place of the derivative

d=dt as

ethms2 thorn bsthorn kTHORNy frac14 ethbsthorn kTHORNye eth123THORN

FIGURE 19 Dynamic models of an electromagnetic shaker and a flexible test package (a) mechanical model

(b) electrical model

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frac12mes2 thorn ethbthorn beTHORNsthorn ethkthorn keTHORN ye frac14 ethbsthorn kTHORNy thorn kb

Rev2

k2bs

Reye eth124THORN

It follows that the transfer function of the shaker head motion with respect to the excitation voltage is

given by

yevfrac14 kb

Re

DethsTHORNDdethsTHORN eth125THORN

where DethsTHORN is the characteristic function of the primary dynamics of the test object

DethsTHORN frac14 ms2 thorn bsthorn k eth126THORN

and DdethsTHORN is the characteristic function of the primary dynamic interactions between the shaker and thetest object

DcethsTHORN frac14 mmes4 thorn frac12methbe thorn bthorn boTHORN thornmeb s

3 thorn frac12methke thorn kTHORN thornmekthorn bethbe thorn boTHORN s2thorn frac12bke thorn ethbe thorn boTHORNk sthorn kke

eth127THORN

where

bo frac14 k2bRe

eth128THORN

It is clear that under low damping conditions DdethsTHORN will produce two resonances as it is fourth order in sand similarly DethsTHORN will produce one antiresonance (trough) corresponding to the resonance of the testobject Note that in the frequency domain s frac14 jv and hence the frequency response function given by

Equation 125 is in fact

yevfrac14 kb

Rb

DethjvTHORNDdethjvTHORN eth129THORN

The magnitude of this frequency response function for a typical test system is sketched in Figure 110

Note that this curve is for the ldquoopen-looprdquo case where there is no feedback from the shaker controller

In practice the shaker controller will be able

to compensate for the resonances and anti-

resonances to some degree depending on its

effectiveness

The main advantages of electromagnetic

shakers are their high frequency range of

operation their high degree of operating flexi-

bility and the high level of accuracy of the

generated shaker motion Faithful reproduction

of complex excitations is possible because of the

advanced electronics and control systems used in

this type of shakers Electromagnetic shakers are

not suitable for heavy-duty applications (large test

objects) however High test-input accelerations

are possible at high frequencies when electromag-

netic shakers are used but their displacement and

velocity capabilities are limited to low or

intermediate values (see Table 11)

100

10

1 10 100Excitation Frequency (Hz)

Antiresonance

Resonance

Shak

erD

ispl

acem

entM

agni

tude

Resonance

1000

FIGURE 110 Frequency response curve of a typical

electromagnetic shaker with a test object

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1221 Transient Exciters

Other varieties of exciters are commonly used in

transient-type vibration testing In these tests

either an impulsive force or an initial excitation is

applied to the test object and the resulting

response is monitored The excitations and the

responses are ldquotransientrdquo in this case Hammer

test drop tests and pluck tests fall into this

category For example a hammer test may be

conducted by hitting the object with an instru-

mented hammer and then measuring the response

of the object The hammer has a force sensor at its

tip as sketched in Figure 111 A piezoelectric or

strain-gage type force sensor may be used More

sophisticated hammers have impedance heads in

place of force sensors An impedance head

measures force and acceleration simultaneously

The results of a hammer test will depend on many

factors for example the dynamics of the hammer

body how firmly the hammer is held during the

impact how quickly the impact is applied and

whether there are multiple impacts

13 Control System

The two primary functions of the shaker control system in vibration testing are (1) to guarantee that the

specified excitation is applied to the test object and (2) to ensure that the dynamic stability (motion

constraints) of the test setup is preserved An operational block diagram illustrating these control

functions is given in Figure 112 The reference input to the control system represents the desired

excitation force that should be applied to the test object In the absence of any control however the force

reaching the test object will be distorted primarily because of (1) dynamic interactions and

nonlinearities of the shaker the test table the mounting fixtures the auxiliary instruments and the test

object itself (2) noise and errors in the signal generator amplifiers filters and other equipment and (3)

external loads and disturbances acting on the test object and other components (for example external

restraints aerodynamic forces friction) To compensate for these distorting factors response

measurements (displacements velocities acceleration and so on) are made at various locations in the

test setup and are used to control the system dynamics In particular the responses of the shaker the test

table and the test object are measured These responses are used to compare the actual excitation felt by

FIGURE 111 An instrumented hammer used in bump

tests or hammer tests

ExcitationInput

(Reference)

Feedback Paths

DriveSignal

ShakerResponse

TestTable

TestObject

Test ObjectResponse

Test TableResponseExciter

(Shaker)(Ram)

Controllerand

Amplifier

FIGURE 112 Operational block diagram illustrating a general shaker control system

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copy 2007 by Taylor amp Francis Group LLC

the test object at the shaker interface with the desired (specified) input The drive signal to the shaker is

modified depending on the error that is present

Two types of control are commonly employed in shaker apparatus simple manual control and

complex automatic control Manual control normally consists of simple open-loop trial-and-error

methods of manual adjustments (or calibration) of the control equipment to obtain a desired dynamic

response The actual response is usually monitored (on an oscilloscope or frequency analyzer screen for

example) during manual-control operations The pretest adjustments in manual control can be very

time-consuming as a result the test object might be subjected to overtesting which could produce

cumulative damage is undesirable and could defeat the test purpose Furthermore the calibration

procedure for the experimental setup must be repeated for each new test object

The disadvantages ofmanual control suggest that automatic control is desirable in complex test schemes

in which high accuracy of testing is desired The first step of automatic control involves automatic

measurement of the system response using control sensors and transducers The measurement is then fed

back into the control system which instantaneously determines the best drive signal to actuate the shaker

in order to get the desired excitation This may be done by either analog or digital methods

Primitive control systems require an accurate mathematical description of the test object This

dependency of the control system on the knowledge of test-object dynamics is clearly undesirable

Performance of a good control system should not be considerably affected by the dynamic interactions

and nonlinearities of the test object or by the nature of the excitation Proper selection of feedback signals

and control-system components can reduce such effects and will make the system robust

In the response-spectrum method of vibration testing it is customary to use displacement control at

low frequencies velocity control at intermediate frequency and acceleration control at high frequencies

This necessitates feedback of displacement velocity and acceleration responses Generally however the

most important feedback is the velocity feedback In sine-sweep tests the shaker velocity must change

steadily over the frequency band of interest In particular the velocity control must be precise near the

resonances of the test object Velocity (speed) feedback has a stabilizing effect on the dynamics which is

desirable This effect is particularly useful in ensuring stability in motion when testing is done near

resonances of lightly damped test objects On the contrary displacement (position) feedback can have a

destabilizing effect on some systems particularly when high feedback gains are used

The controller usually consists of various instruments equipment and computation hardware and

software Often the functions of the data-acquisition and processing system overlap with those of the

controller to some extent As an example consider the digital-controller of vibration testing apparatus

First the responses are measured through sensors (and transducers) filtered and amplified

(conditioned) These data channels may be passed through a multiplexer whose purpose is to select

one data channel at a time for processing Most modern data acquisition hardware does not need a

separate multiplexer to handle multiple signals The analog data are converted into digital data using

analog-to-digital converters (ADCs) The resulting sampled data are stored on a disk or as a block data in

the computer memory The reference input signal (typically a signal recorded on an FM tape) is also

sampled (if it is not already in the digital form) using an ADC and fed into the computer Digital

processing is done on the reference signal and the response data with the objective of computing the

command signal to drive the shaker The digital command signal is converted into an analog signal using

a digital-to-analog converter (DAC) and amplified (conditioned) before it is used to drive the exciter

The nature of the control components depends to a large extent on the nature and objectives of the

particular test to be conducted Some of the basic components in a shaker controller are described in

the following subsections

131 Components of a Shaker Controller

1311 Compressor

A compressor circuit is incorporated in automatic excitation control devices to control the excitation-

input level automatically The level of control depends on the feedback signal from a control sensor and

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the specified (reference) excitation signal Usually the compressor circuit is included in the excitation-

signal generator (for example in a sine generator) The control by this means may be done on the basis of

a single-frequency component (eg the fundamental frequency)

1312 Equalizer (Spectrum Shaper)

Random-signal equalizers are used to shape the spectrum of a random signal in a desired manner In

essence and equalizer consists of a bank of narrow-band filters (for example 80 filters) in parallel over

the operating frequency range By passing the signal through each filter the spectral density (or the mean

square value) of the signal in that narrow frequency band (for example each one-third-octave band) is

determined This is compared with the desired spectral level and automatic adjustment is made in that

filter in case there is an error In some systems response-spectrum analysis is made in place of power

spectral density analysis In that case the equalizer consists of a bank of simple oscillators whose

resonant frequencies are distributed over the operating frequency range of the equalizer The feedback

signal is passed through each oscillator and the peak value of its output is determined This value is

compared with the desired response spectrum value at that frequency If there is an error automatic gain

adjustment is made in the appropriate excitation signal components

Random-noise equalizers are used in conjunction with random signal generators They receive

feedback signals from the control sensors In some digital control systems there are algorithms (software)

that are used to iteratively converge the spectrum of the excitation signal felt by the test object into the

desired spectrum

1313 Tracking Filter

Many vibration tests are based on single-frequency excitations In such cases the control functions

should be performed on the basis of the amplitudes of the fundamental-frequency component of the

signal A tracking filter is simply a frequency-tuned band-pass filter It automatically tunes the center

frequency of its very narrow-band-pass filter to the frequency of a carrier signal Then when a noisy

signal is passed through the tuned filter the output of the filter will be the required fundamental

frequency component in the signal Tracking filters also are useful in obtaining amplitudendashfrequency

plots using an XndashY plotter In such cases the frequency value comes from the signal generator (sweep

oscillator) which produces the carrier signal to the tracking filter The tracking filter then determines the

corresponding amplitude of a signal that is fed into it Most tracking filters have dual channels so that two

signals can be handled (tracked) simultaneously

1314 Excitation Controller (Amplitude Servo-Monitor)

An excitation controller is typically an integral part of the signal generator It can be set so that automatic

sweep between two frequency limits can be performed at a selected sweep rate (linear or logarithmic)

More advanced excitation controllers have the capability of an automatic switch-over between constant-

displacement constant-velocity and constant-acceleration excitation-input control at specified

frequencies over the sweep frequency interval Consequently integrator circuits should be present

within the excitation controller unit to determine velocities and displacements from acceleration signals

Sometimes integration is performed by a separate unit called a vibration meter This unit also offers

the operator the capability of selecting the desired level of each signal (acceleration velocity or

displacement) There is an automatic cut-off level for large displacement values that could result from

noise in acceleration signals A compressor is also a subcomponent of the excitation controller The

complete unit is sometimes known as an amplitude servo-monitor

132 Signal-Generating Equipment

Shakers are force-generating devices that are operated using drive (excitation) signals generated from a

source The excitation-signal source is known as the signal generator Three major types of signal

generators are used in vibration testing applications (1) oscillators (2) random-signal generators and

(3) storage devices In some units oscillators and random-signal generators are combined We shall

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copy 2007 by Taylor amp Francis Group LLC

discuss these two generators separately however because of their difference in function It also should be

noted that almost any digital signal (deterministic or random) can be generated by a digital computer

using a suitable computer program the signal eventually can be passed through a DAC to obtain

the corresponding analog signal These lsquodigitalrsquo signal generators along with analog sources such as

magnetic tape players (FM) are classified into the category of storage devices

The dynamic range of equipment is the ratio of the maximum and minimum output levels (expressed

in decibels) at which it is capable of operating without significant error This is an important specification

for many types of equipment particularly for signal-generating devices The output level of the signal

generator should be set to a value within its dynamic range

1321 Oscillators

Oscillators are essentially single-frequency generators Typically sine signals are generated but other

waveforms (such as rectangular and triangular pulses) are also available in most oscillators Normally

an oscillator has two modes of operation (1) sweeping up and down between two frequency limits and

(2) dwelling at a specified frequency In the sweep operation the sweep rate should be specified This can

be done either on a linear scale (Hzmin) or on a logarithmic scale (octavesmin) In the dwell operation

the frequency points (or intervals) should be specified In either case a desired signal level can be chosen

using the gain-control knob An oscillator that is operated exclusively in the sweep mode is called a sweep

oscillator

The early generation of oscillators employed variable inductor-capacitor types of electronic circuits to

generate signals oscillating at a desired frequency The oscillator is tuned to the required frequency by

varying the capacitance or inductance parameters A DC voltage is applied to energize the capacitor

and to obtain the desired oscillating voltage signal which subsequently is amplified and conditioned

Modern oscillators use operational amplifier circuits along with resistor capacitor and semiconductor

(SC) elements Also common are crystal (quartz) parallel-resonance oscillators used to generate voltage

signals accurately at a fixed frequency The circuit is activated using a DC-voltage source Other

frequencies of interest are obtained by passing this high-frequency signal through a frequency converter

The signal is then conditioned (amplified and filtered) Required shaping (for example rectangular

pulse) is obtained using a shape circuit Finally the required signal level is obtained by passing the

resulting signal through a variable-gain amplifier A block diagram of an oscillator illustrating various

stages in the generation of a periodic signal is given in Figure 113

A typical oscillator offers a choice of several (typically six) linear and logarithmic frequency ranges and

a sizable level of control capability (for example 80 dB) Upper and lower frequency limits in a sweep can

be preset on the front panel to any of the available frequency ranges Sweep-rate settings are continuously

DC Voltage

Oscillator

FrequencySpecification

FrequencyConverter

FilterAmplifier

ShaperPeriodicSignal

FrequencyCounter

Fixed-FrequencySignal

Variable-GainOutput

Amplifier

SignalSpecification

LevelSpecification

FIGURE 113 Block diagram of an oscillator-type signal generator

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copy 2007 by Taylor amp Francis Group LLC

  • 53191fm
    • Vibration Monitoring Testing and Instrumentation
      • Preface
      • Acknowledgments
      • Editor-in-Chief
      • Contributors
      • Contents
      • Related Titles
          • 53191ch1
            • Table of Contents
            • Chapter 1 Vibration Instrumentation
              • Summary
              • 11 Introduction
              • 12 Vibration Exciters
                • 121 Shaker Selection
                  • 1211 Force Rating
                  • 1212 Power Rating
                  • 1213 Stroke Rating
                  • 1214 Hydraulic Shakers
                  • 1215 Inertial Shakers
                  • 1216 Electromagnetic Shakers
                    • 122 Dynamics of Electromagnetic Shakers
                      • 1221 Transient Exciters
                          • 13 Control System
                            • 131 Components of a Shaker Controller
                              • 1311 Compressor
                              • 1312 Equalizer (Spectrum Shaper)
                              • 1313 Tracking Filter
                              • 1314 Excitation Controller (Amplitude Servo-Monitor)
                                • 132 Signal-Generating Equipment
                                  • 1321 Oscillators
                                  • 1322 Random Signal Generators
                                  • 1323 Tape Players
                                  • 1324 Data Processing
                                      • 14 Performance Specification
                                        • 141 Parameters for Performance Specification
                                          • 1411 Time-Domain Specifications
                                          • 1412 Frequency-Domain Specifications
                                            • 142 Linearity
                                            • 143 Instrument Ratings
                                              • 1431 Rating Parameters
                                                • 144 Accuracy and Precision
                                                  • 15 Motion Sensors and Transducers
                                                    • 151 Potentiometer
                                                      • 1511 Potentiometer Resolution
                                                      • 1512 Optical Potentiometer
                                                        • 152 Variable-Inductance Transducers
                                                          • 1521 Mutual-Induction Transducers
                                                          • 1522 Linear-Variable Differential Transformer
                                                          • 1523 Signal Conditioning
                                                            • 153 Mutual-Induction Proximity Sensor
                                                            • 154 Selfinduction Transducers
                                                            • 155 Permanent-Magnet Transducers
                                                            • 156 Alternating Current Permanent-Magnet Tachometer
                                                            • 157 Alternating Current Induction Tachometer
                                                            • 158 Eddy Current Transducers
                                                            • 159 Variable-Capacitance Transducers
                                                              • 1591 Capacitive Displacement Sensors
                                                              • 1592 Capacitive Angular Velocity Sensor
                                                              • 1593 Capacitance Bridge Circuit
                                                                • 1510 Piezoelectric Transducers
                                                                  • 15101 Sensitivity
                                                                  • 15102 Piezoelectric Accelerometer
                                                                  • 15103 Charge Amplifier
                                                                      • 16 Torque Force and Other Sensors
                                                                        • 161 Strain Gage Sensors
                                                                          • 1611 Equations for Strain Gage Measurements
                                                                          • 1612 Bridge Sensitivity
                                                                          • 1613 The Bridge Constant
                                                                          • 1614 The Calibration Constant
                                                                          • 1615 Data Acquisition
                                                                          • 1616 Accuracy Considerations
                                                                          • 1617 Semiconductor Strain Gages
                                                                          • 1618 Force and Torque Sensors
                                                                          • 1619 Strain Gage Torque Sensors
                                                                          • 16110 Deflection Torque Sensors
                                                                          • 16111 Variable-Reluctance Torque Sensor
                                                                          • 16112 Reaction Torque Sensors
                                                                            • 162 Miscellaneous Sensors
                                                                              • 1621 Stroboscope
                                                                              • 1622 Fiber Optic Sensors and Lasers
                                                                              • 1623 Fiber-Optic Gyroscope
                                                                              • 1624 Laser Doppler Interferometer
                                                                              • 1625 Ultrasonic Sensors
                                                                              • 1626 Gyroscopic Sensors
                                                                                  • References
                                                                                  • Appendix 1A Virtual Instrumentation for Data Acquisition Analysis and Presentation
                                                                                    • Summary
                                                                                    • List of Abbreviations
                                                                                    • 1A1 Dynamic Signals
                                                                                      • 1A11 Acquiring and Simulating Dynamic Signals
                                                                                        • 1A111 Aliasing
                                                                                        • 1A112 Time Continuity
                                                                                            • 1A2 Measurement Configuration Considerations
                                                                                              • 1A21 Input Signal Considerations
                                                                                                • 1A211 Input Pseudodifferential and Differential Configuration
                                                                                                • 1A212 Gain
                                                                                                • 1A213 Input Coupling
                                                                                                • 1A214 Integrated Electronic Piezoelectric Excitation
                                                                                                • 1A215 Nyquist Frequency and Bandwidth
                                                                                                • 1A216 Analog-to-Digital Conversion
                                                                                                • 1A217 Antialias Filters
                                                                                                • 1A218 Input Filter Delay
                                                                                                • 1A219 Overload Detection
                                                                                                  • 1A22 Output Signal Considerations
                                                                                                    • 1A221 Output Pseudodifferential and Differential Configuration
                                                                                                    • 1A222 Attenuation
                                                                                                    • 1A223 Digital-to-Analog Conversion
                                                                                                    • 1A224 Anti-imaging and Interpolation Filters
                                                                                                    • 1A225 Output Filter Delay
                                                                                                        • 1A3 Scaling and Calibration
                                                                                                          • 1A31 Scaling to Engineering Units
                                                                                                          • 1A32 Performing System Calibration
                                                                                                            • 1A321 Propagation Delay Calibration
                                                                                                                • 1A4 Limit Testing Analysis
                                                                                                                  • 1A41 Limit Testing Overview
                                                                                                                  • 1A42 Using the SVT Limit Testing VI
                                                                                                                    • 1A5 Integration
                                                                                                                      • 1A51 Introduction to Integration
                                                                                                                      • 1A52 Implementing Integration
                                                                                                                        • 1A521 Challenges when Integrating Vibration Data
                                                                                                                          • 1A53 Time-Domain Integration
                                                                                                                            • 1A531 Single-Shot Acquisition and Integration
                                                                                                                            • 1A532 Continuous Acquisition and Integration
                                                                                                                              • 1A54 Frequency-Domain Integration
                                                                                                                                • 1A6 Vibration-Level Measurements
                                                                                                                                  • 1A61 Measuring the Root Mean Square Level
                                                                                                                                    • 1A611 Single-Shot Buffered Acquisition
                                                                                                                                    • 1A612 Continuous Signal Acquisition
                                                                                                                                      • 1A62 Performing a Running RMS Level Measurement
                                                                                                                                      • 1A63 Computing the Peak Level
                                                                                                                                      • 1A64 Computing the Crest Factor
                                                                                                                                        • 1A7 Frequency Analysis
                                                                                                                                          • 1A71 FFT Fundamentals
                                                                                                                                            • 1A711 Number of Samples
                                                                                                                                            • 1A712 Frequency Resolution
                                                                                                                                            • 1A713 Maximum Resolvable Frequency
                                                                                                                                            • 1A714 Minimum Resolvable Frequency
                                                                                                                                            • 1A715 Number of Spectral Lines
                                                                                                                                            • 1A716 Relationship between Time-Domain and Frequency-Domain Specifications and Parameters
                                                                                                                                              • 1A72 Increasing Frequency Resolution
                                                                                                                                                • 1A721 Zoom FFT Analysis
                                                                                                                                                • 1A722 Frequency Resolution of the Zoom FFT VIs
                                                                                                                                                • 1A723 Zoom Measurement
                                                                                                                                                • 1A724 Zoom Settings
                                                                                                                                                • 1A725 Subset Analysis
                                                                                                                                                    • 1A8 Transient Analysis
                                                                                                                                                      • 1A81 Transient Analysis with the Sound and Vibration Toolkit
                                                                                                                                                      • 1A82 Performing an STFT vs Time
                                                                                                                                                        • 1A821 Selecting the FFT Block Size
                                                                                                                                                        • 1A822 Overlapping
                                                                                                                                                        • 1A823 Using the SVT STFT vs Time VI
                                                                                                                                                          • 1A83 Performing an STFT vs Rotational Speed
                                                                                                                                                            • 1A831 Converting the Pulse Train to Rotational Speed
                                                                                                                                                            • 1A832 STFT vs RPM
                                                                                                                                                              • 1A84 Measuring a Shock Response Spectrum
                                                                                                                                                                • 1A9 Waterfall Display
                                                                                                                                                                  • 1A91 Using the Display VIs
                                                                                                                                                                    • 1A911 Initializing the Display
                                                                                                                                                                    • 1A912 Sending Data to the Display
                                                                                                                                                                    • 1A913 Waterfall Display for Frequency Analysis
                                                                                                                                                                    • 1A914 Waterfall Display for Transient Analysis
                                                                                                                                                                    • 1A915 Waterfall Display for Octave Spectra
                                                                                                                                                                        • 1A10 Swept-Sine Measurements
                                                                                                                                                                          • 1A101 Swept-Sine Overview
                                                                                                                                                                          • 1A102 Choosing Swept-Sine vs FFT Measurements
                                                                                                                                                                          • 1A103 Taking a Swept-Sine Measurement
                                                                                                                                                                          • 1A104 Swept-Sine Measurement Example
                                                                                                                                                                              • Bibliography
                                                                                                                                                                              • Related Titles
                                                                                                                                                                                  • 53191ch2
                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                    • Chapter 2 Signal Conditioning and Modification
                                                                                                                                                                                      • Summary
                                                                                                                                                                                      • 21 Introduction
                                                                                                                                                                                      • 22 Amplifiers
                                                                                                                                                                                        • 221 Operational Amplifier
                                                                                                                                                                                        • 222 Use of Feedback in Opamp
                                                                                                                                                                                        • 223 Voltage Current and Power Amplifiers
                                                                                                                                                                                          • 2231 Charge Amplifiers
                                                                                                                                                                                            • 224 Instrumentation Amplifiers
                                                                                                                                                                                              • 2241 Differential Amplifier
                                                                                                                                                                                              • 2242 Common Mode
                                                                                                                                                                                                • 225 Amplifier Performance Ratings
                                                                                                                                                                                                  • 2251 Common-Mode Rejection Ratio
                                                                                                                                                                                                    • 226 Component Interconnection
                                                                                                                                                                                                      • 2261 Impedance Characteristics
                                                                                                                                                                                                      • 2262 Cascade Connection of Devices
                                                                                                                                                                                                      • 2263 AC-Coupled Ampliers
                                                                                                                                                                                                          • 23 Analog Filters
                                                                                                                                                                                                            • 231 Passive Filters and Active Filters
                                                                                                                                                                                                              • 2311 Number of Poles
                                                                                                                                                                                                                • 232 Low-Pass Filters
                                                                                                                                                                                                                  • 2321 Low-Pass Butterworth Filter
                                                                                                                                                                                                                    • 233 High-Pass Filters
                                                                                                                                                                                                                    • 234 Band-Pass Filters
                                                                                                                                                                                                                      • 2341 Resonance-Type Band-Pass Filters
                                                                                                                                                                                                                        • 235 Band-Reject Filters
                                                                                                                                                                                                                          • 24 Modulators and Demodulators
                                                                                                                                                                                                                            • 241 Amplitude Modulation
                                                                                                                                                                                                                              • 2411 Modulation Theorem
                                                                                                                                                                                                                              • 2412 Side Frequencies and Side Bands
                                                                                                                                                                                                                                • 242 Application of Amplitude Modulation
                                                                                                                                                                                                                                  • 2421 Fault Detection and Diagnosis
                                                                                                                                                                                                                                    • 243 Demodulation
                                                                                                                                                                                                                                      • 25 Analog ndashDigital Conversion
                                                                                                                                                                                                                                        • 251 Digital-to-Analog Conversion
                                                                                                                                                                                                                                          • 2511 DAC Error Sources
                                                                                                                                                                                                                                            • 252 Analog-to-Digital Conversion
                                                                                                                                                                                                                                            • 253 Analog-to-Digital Converter Performance Characteristics
                                                                                                                                                                                                                                              • 2531 Resolution and Quantization Error
                                                                                                                                                                                                                                              • 2532 Monotonicity Nonlinearity and Offset Error
                                                                                                                                                                                                                                              • 2533 Analog-to-Digital Converter Conversion Rate
                                                                                                                                                                                                                                                • 254 Sample-and-Hold Circuitry
                                                                                                                                                                                                                                                • 255 Digital Filters
                                                                                                                                                                                                                                                  • 2551 Software Implementation and Hardware Implementation
                                                                                                                                                                                                                                                      • 26 Bridge Circuits
                                                                                                                                                                                                                                                        • 261 Wheatstone Bridge
                                                                                                                                                                                                                                                        • 262 Constant-Current Bridge
                                                                                                                                                                                                                                                        • 263 Bridge Amplifiers
                                                                                                                                                                                                                                                          • 2631 Half-Bridge Circuits
                                                                                                                                                                                                                                                            • 264 Impedance Bridges
                                                                                                                                                                                                                                                              • 2641 Owen Bridge
                                                                                                                                                                                                                                                              • 2642 Wien-Bridge Oscillator
                                                                                                                                                                                                                                                                  • 27 Linearizing Devices
                                                                                                                                                                                                                                                                    • 271 Linearization by Software
                                                                                                                                                                                                                                                                    • 272 Linearization by Hardware Logic
                                                                                                                                                                                                                                                                    • 273 Analog Linearizing Circuitry
                                                                                                                                                                                                                                                                    • 274 Offsetting Circuitry
                                                                                                                                                                                                                                                                    • 275 Proportional-Output Circuitry
                                                                                                                                                                                                                                                                      • 2751 Curve-Shaping Circuitry
                                                                                                                                                                                                                                                                          • 28 Miscellaneous Signal Modification Circuitry
                                                                                                                                                                                                                                                                            • 281 Phase Shifters
                                                                                                                                                                                                                                                                            • 282 Voltage-to-Frequency Converter
                                                                                                                                                                                                                                                                            • 283 Frequency-to-Voltage Converter
                                                                                                                                                                                                                                                                            • 284 Voltage-to-Current Converters
                                                                                                                                                                                                                                                                            • 285 Peak-Hold Circuits
                                                                                                                                                                                                                                                                              • 29 Signal Analyzers and Display Devices
                                                                                                                                                                                                                                                                                • 291 Signal Analyzers
                                                                                                                                                                                                                                                                                • 292 Oscilloscopes
                                                                                                                                                                                                                                                                                  • 2921 Triggering
                                                                                                                                                                                                                                                                                  • 2922 Lissajous Patterns
                                                                                                                                                                                                                                                                                  • 2923 Digital Oscilloscopes
                                                                                                                                                                                                                                                                                      • Bibliography
                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                          • 53191ch3
                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                            • Chapter 3 Vibration Testing
                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                              • 31 Introduction
                                                                                                                                                                                                                                                                                              • 32 Representation of a Vibration Environment
                                                                                                                                                                                                                                                                                                • 321 Test Signals
                                                                                                                                                                                                                                                                                                  • 3211 Stochastic vs Deterministic Signals
                                                                                                                                                                                                                                                                                                    • 322 Deterministic Signal Representation
                                                                                                                                                                                                                                                                                                      • 3221 Single-Frequency Signals
                                                                                                                                                                                                                                                                                                      • 3222 Sine Sweep
                                                                                                                                                                                                                                                                                                      • 3223 Sine Dwell
                                                                                                                                                                                                                                                                                                      • 3224 Decaying Sine
                                                                                                                                                                                                                                                                                                      • 3225 Sine Beat
                                                                                                                                                                                                                                                                                                      • 3226 Sine Beat with Pauses
                                                                                                                                                                                                                                                                                                      • 3227 Multifrequency Signals
                                                                                                                                                                                                                                                                                                      • 3228 Actual Excitation Records
                                                                                                                                                                                                                                                                                                      • 3229 Simulated Excitation Signals
                                                                                                                                                                                                                                                                                                        • 323 Stochastic Signal Representation
                                                                                                                                                                                                                                                                                                          • 3231 Ergodic Random Signals
                                                                                                                                                                                                                                                                                                          • 3232 Stationary Random Signals
                                                                                                                                                                                                                                                                                                          • 3233 Independent and Uncorrelated Signals
                                                                                                                                                                                                                                                                                                          • 3234 Transmission of Random Excitations
                                                                                                                                                                                                                                                                                                            • 324 Frequency-Domain Representations
                                                                                                                                                                                                                                                                                                              • 3241 Fourier Spectrum Method
                                                                                                                                                                                                                                                                                                              • 3242 Power Spectral Density Method
                                                                                                                                                                                                                                                                                                                • 325 Response Spectrum
                                                                                                                                                                                                                                                                                                                  • 3251 Displacement Velocity and Acceleration Spectra
                                                                                                                                                                                                                                                                                                                  • 3252 Response-Spectra Plotting Paper
                                                                                                                                                                                                                                                                                                                  • 3253 Zero-Period Acceleration
                                                                                                                                                                                                                                                                                                                  • 3254 Uses of Response Spectra
                                                                                                                                                                                                                                                                                                                    • 326 Comparison of Various Representations
                                                                                                                                                                                                                                                                                                                      • 33 Pretest Procedures
                                                                                                                                                                                                                                                                                                                        • 331 Purpose of Testing
                                                                                                                                                                                                                                                                                                                        • 332 Service Functions
                                                                                                                                                                                                                                                                                                                          • 3321 Active Equipment
                                                                                                                                                                                                                                                                                                                          • 3322 Passive Equipment
                                                                                                                                                                                                                                                                                                                          • 3323 Functional Testing
                                                                                                                                                                                                                                                                                                                            • 333 Information Acquisition
                                                                                                                                                                                                                                                                                                                              • 3331 Interface Details
                                                                                                                                                                                                                                                                                                                              • 3332 Effect of Neglecting Interface Dynamics
                                                                                                                                                                                                                                                                                                                              • 3333 Effects of Damping
                                                                                                                                                                                                                                                                                                                              • 3334 Effects of Inertia
                                                                                                                                                                                                                                                                                                                              • 3335 Effect of Natural Frequency
                                                                                                                                                                                                                                                                                                                              • 3336 Effect of Excitation Frequency
                                                                                                                                                                                                                                                                                                                              • 3337 Other Effects of Interface
                                                                                                                                                                                                                                                                                                                                • 334 Test-Program Planning
                                                                                                                                                                                                                                                                                                                                  • 3341 Testing of Cabinet-Mounted Equipment
                                                                                                                                                                                                                                                                                                                                    • 335 Pretest Inspection
                                                                                                                                                                                                                                                                                                                                      • 34 Testing Procedures
                                                                                                                                                                                                                                                                                                                                        • 341 Resonance Search
                                                                                                                                                                                                                                                                                                                                        • 342 Methods of Determining Frequency-Response Functions
                                                                                                                                                                                                                                                                                                                                          • 3421 Fourier Transform Method
                                                                                                                                                                                                                                                                                                                                          • 3422 Spectral Density Method
                                                                                                                                                                                                                                                                                                                                          • 3423 Harmonic Excitation Method
                                                                                                                                                                                                                                                                                                                                            • 343 Resonance-Search Test Methods
                                                                                                                                                                                                                                                                                                                                              • 3431 Hammer (Bump) Test and Drop Test
                                                                                                                                                                                                                                                                                                                                              • 3432 Pluck Test
                                                                                                                                                                                                                                                                                                                                              • 3433 Shaker Tests
                                                                                                                                                                                                                                                                                                                                                • 344 Mechanical Aging
                                                                                                                                                                                                                                                                                                                                                  • 3441 Equivalence for Mechanical Aging
                                                                                                                                                                                                                                                                                                                                                  • 3442 Excitation-Intensity Equivalence
                                                                                                                                                                                                                                                                                                                                                  • 3443 Dynamic-Excitation Equivalence
                                                                                                                                                                                                                                                                                                                                                  • 3444 Cumulative Damage Theory
                                                                                                                                                                                                                                                                                                                                                    • 345 Test-Response Spectrum Generation
                                                                                                                                                                                                                                                                                                                                                    • 346 Instrument Calibration
                                                                                                                                                                                                                                                                                                                                                    • 347 Test-Object Mounting
                                                                                                                                                                                                                                                                                                                                                    • 348 Test-Input Considerations
                                                                                                                                                                                                                                                                                                                                                      • 3481 Test Nomenclature
                                                                                                                                                                                                                                                                                                                                                      • 3482 Testing with Uncorrelated Excitations
                                                                                                                                                                                                                                                                                                                                                      • 3483 Symmetrical Rectilinear Testing
                                                                                                                                                                                                                                                                                                                                                      • 3484 Geometry vs Dynamics
                                                                                                                                                                                                                                                                                                                                                      • 3485 Some Limitations
                                                                                                                                                                                                                                                                                                                                                      • 3486 Testing Black Boxes
                                                                                                                                                                                                                                                                                                                                                      • 3487 Phasing of Excitations
                                                                                                                                                                                                                                                                                                                                                      • 3488 Testing a Gray or White Box
                                                                                                                                                                                                                                                                                                                                                      • 3489 Overtesting in Multitest Sequences
                                                                                                                                                                                                                                                                                                                                                          • 35 Some Practical Information
                                                                                                                                                                                                                                                                                                                                                            • 351 Random Vibration Test Example
                                                                                                                                                                                                                                                                                                                                                            • 352 Vibration Shakers and Control Systems
                                                                                                                                                                                                                                                                                                                                                              • Bibliography
                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                  • 53191ch4
                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                    • Chapter 4 Experimental Modal Analysis
                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                      • 41 Introduction
                                                                                                                                                                                                                                                                                                                                                                      • 42 Frequency-Domain Formulation
                                                                                                                                                                                                                                                                                                                                                                        • 421 Transfer-Function Matrix
                                                                                                                                                                                                                                                                                                                                                                        • 422 Principle of Reciprocity
                                                                                                                                                                                                                                                                                                                                                                          • 43 Experimental Model Development
                                                                                                                                                                                                                                                                                                                                                                            • 431 Extraction of the Time-Domain Model
                                                                                                                                                                                                                                                                                                                                                                              • 44 Curve Fitting of Transfer Functions
                                                                                                                                                                                                                                                                                                                                                                                • 441 Problem Identification
                                                                                                                                                                                                                                                                                                                                                                                • 442 Single- and Multi-Degree-of-Freedom Techniques
                                                                                                                                                                                                                                                                                                                                                                                • 443 Single-Degree-of-Freedom Parameter Extraction in the Frequency Domain
                                                                                                                                                                                                                                                                                                                                                                                  • 4431 Circle-Fit Method
                                                                                                                                                                                                                                                                                                                                                                                    • Case of Viscous Damping
                                                                                                                                                                                                                                                                                                                                                                                    • Case of Hysteretic Damping
                                                                                                                                                                                                                                                                                                                                                                                      • 4432 Peak-Picking Method
                                                                                                                                                                                                                                                                                                                                                                                        • 444 Multi-Degree of Freedom Curve Fitting
                                                                                                                                                                                                                                                                                                                                                                                          • 4441 Formulation of the Method
                                                                                                                                                                                                                                                                                                                                                                                            • 445 A Comment on Static Modes and Rigid-Body Modes
                                                                                                                                                                                                                                                                                                                                                                                            • 446 Residue Extraction
                                                                                                                                                                                                                                                                                                                                                                                              • 45 Laboratory Experiments
                                                                                                                                                                                                                                                                                                                                                                                                • 451 Lumped-Parameter System
                                                                                                                                                                                                                                                                                                                                                                                                  • 4511 Frequency-Domain Test
                                                                                                                                                                                                                                                                                                                                                                                                  • 4512 Time-Domain Tests
                                                                                                                                                                                                                                                                                                                                                                                                    • 452 Distributed-Parameter System
                                                                                                                                                                                                                                                                                                                                                                                                      • 46 Commercial EMA Systems
                                                                                                                                                                                                                                                                                                                                                                                                        • 461 System Configuration
                                                                                                                                                                                                                                                                                                                                                                                                          • 4611 FFT Analysis Options
                                                                                                                                                                                                                                                                                                                                                                                                          • 4612 Modal Analysis Components
                                                                                                                                                                                                                                                                                                                                                                                                              • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                  • 53191ch5
                                                                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                    • Chapter 5 Mechanical Shock
                                                                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                      • 51 Definitions
                                                                                                                                                                                                                                                                                                                                                                                                                        • 511 Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 512 Simple (or Perfect) Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 513 Half-Sine Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 514 Versed-Sine (or Haversine) Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 515 Terminal Peak Sawtooth Shock or Final Peak Sawtooth Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 516 Rectangular Shock
                                                                                                                                                                                                                                                                                                                                                                                                                          • 5161 Trapezoidal Shock
                                                                                                                                                                                                                                                                                                                                                                                                                              • 52 Description in the Time Domain
                                                                                                                                                                                                                                                                                                                                                                                                                              • 53 Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                • 531 Need
                                                                                                                                                                                                                                                                                                                                                                                                                                • 532 Shock Response Spectrum Definition
                                                                                                                                                                                                                                                                                                                                                                                                                                • 533 Response of a Linear One-Degree-of-Freedom System
                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5331 Shock Defined by a Force
                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5332 Shock Defined by an Acceleration
                                                                                                                                                                                                                                                                                                                                                                                                                                    • 534 Definitions
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5341 Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5342 Absolute Acceleration Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5343 Relative Displacement Shock Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5344 Primary Positive Shock Response Spectrum or Initial Positive Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5345 Primary (or Initial) Negative Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5346 Secondary (or Residual) Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5347 Positive (or Maximum Positive) Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5348 Negative (or Maximum Negative) Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5349 Maximax Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53410 Choice of Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                        • 535 Standardized Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5351 Definition
                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5352 Standardized Shock Response Spectra of Simple Shocks
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53521 Half-Sine Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53522 Versed Sine Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53523 Terminal Peak Sawtooth Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53524 Rectangular Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53525 Trapezoidal Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 536 Choice of Damping
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 537 Shock Response Spectra Domains
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 538 Algorithms for Calculation of the Shock Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 539 Choice of the Digitization Frequency of the Signal
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5310 Use of Shock Response Spectra for the Study of Systems with Several Degrees of Freedom
                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 54 Pyroshocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 55 Use of Shock Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 551 Severity Comparison of Several Shocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 552 Test Specification Development from Real Environment Data
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5521 Synthesis of Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5522 Nature of the Specification
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5523 Choice of Shape
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5524 Amplitude
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5525 Duration
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5526 Difficulties
                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 56 Standards
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 561 Types of Standards
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 562 Installation Conditions of Test Item
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 563 Uncertainty Factor
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 564 Bump Test
                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 57 Damage Boundary Curve
                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 571 Definition
                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 572 Analysis of Test Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 58 Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 581 Main Types
                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 582 Impact Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5821 Universal Shock-Test Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 58211 Impact Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 58212 Impulse Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 583 Shock Simulators (Programmers)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5831 Half-Sine Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58311 Shock Duration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58312 Impact Velocity
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58313 Maximum Deformation of the Shock Simulator (Programmer)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58314 Shock Amplitude
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58315 Characteristics of the Target
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5832 Terminal Peak Sawtooth Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5833 Rectangular Pulse ndash Trapezoidal Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5834 Universal Shock Simulator (Programmer)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 58341 Generating a Half-Sine Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 58342 Generating a Terminal Peak Sawtooth Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 58343 Trapezoidal Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 584 Limitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5841 Limitations of the Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5842 Limitations of Shock Simulators
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 585 Pneumatic Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 586 High Impact Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5861 Lightweight High Impact Shock Machine
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5862 Medium Weight High Impact Shock Machine
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 587 Specific Test Facilities
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 59 Generation of Shock Using Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 591 Principle Behind the Generation of a Simple Shape Signal versus Time
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 592 Main Advantages
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 593 Pre- and Postshocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5931 Requirements
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5932 Solutions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 59321 Optimized Pre- and Postpulses
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5933 Incidence on the Shock Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 594 Limitations of Electrodynamic Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5941 Mechanical Limitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 59411 Abacuses
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5942 Electronic Limitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 595 The Use of Electrohydraulic Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 510 Control by a Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 5101 Principle
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 5102 Principal Shapes of Elementary Signals
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 51021 Decaying Sinusoid
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 51022 ZERD Function
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 51023 WAVSIN Waveform
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 5103 Comparison of WAVSIN SHOC Waveforms and Decaying Sinusoid
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 5104 Criticism of Control by a Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 511 Pyrotechnic Shock Simulation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5111 Simulation Using Pyrotechnic Facilities
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5112 Simulation Using Metal-to-Metal Impact
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5113 Simulation Using Electrodynamic Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5114 Simulation Using Conventional Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53191ch6
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Chapter 6 Machine Condition Monitoring and Fault Diagnostics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 61 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 62 Machinery Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 621 Causes of Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 622 Types of Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 623 Frequency of Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 63 Basic Maintenance Strategies
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 631 Run-to-Failure (Breakdown) Maintenance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 632 Scheduled (Preventative) Maintenance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 633 Condition-Based (Predictive Proactive Reliability Centered On-Condition) Maintenance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 64 Factors Which Influence Maintenance Strategy
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 65 Machine Condition Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 651 Periodic Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 652 Continuous Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 66 Transducer Selection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 661 Noncontact Displacement Transducers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 662 Velocity Transducers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 663 Acceleration Transducers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 67 Transducer Location
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 68 Recording and Analysis Instrumentation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 681 Vibration Meters
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 682 Data Collectors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 683 Frequency-Domain Analyzers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 684 Time-Domain Instruments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 685 Tracking Analyzers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 69 Display Formats and Analysis Tools
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 691 Time Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6911 Time-Waveform Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6912 Time-Waveform Indices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6913 Time-Synchronous Averaging
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6914 Negative Averaging
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6915 Orbits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6916 Probability Density Functions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6917 Probability Density Moments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 692 Frequency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6921 Band-Pass Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6922 Shock Pulse (Spike Energy)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6923 Enveloped Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6924 Signature Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6925 Cascades (Waterfall Plots)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6926 Masks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6927 Frequency-Domain Indices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 693 Modal Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 694 Quefrency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 610 Fault Detection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 6101 Standards
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61011 Standards Based on Machinery Type
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61012 Standards Based on Vibration Severity
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 6102 Acceptance Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 61021 Statistical Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 6103 Frequency-Domain Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61031 Limited Band Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61032 Constant Bandwidth Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61033 Constant Percentage Bandwidth Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 611 Fault Diagnostics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 6111 Forcing Functions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61111 Unbalance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61112 Misalignment
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61113 Mechanical Looseness
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61114 Soft Foot
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61115 Rubs
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61116 Resonances
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61117 Oil Whirl
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61118 Oil Whip
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61119 Structural Vibrations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 611110 Foundation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 6112 Specific Machine Components
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 61121 Damaged or Worn Rolling-Element Bearings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 61122 Damaged or Worn Gears
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 6113 Specific Machine Types
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61131 Pumps
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61132 Fans
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61133 Electric Motors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61134 Steam and Gas Turbines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61135 Compressors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61136 Reciprocating Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 6114 Advanced Fault Diagnostic Techniques
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 53191ch7
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • Chapter 7 Vibration-Based Tool Condition Monitoring Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 71 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 72 Mechanics of Turning
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 721 General Terms
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 722 Chatter Vibrations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 723 Tool Wear
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7231 Tool Failure Mechanisms
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7232 Tool Failure Modes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7233 Tool Wear Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7234 Tool Wear Stages
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 73 Vibration Signal Recording
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 731 Direct and Indirect Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 732 Sensor Requirements for Tool Wear Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 733 Force Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7331 Direct Measurement Dynamometers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7332 Indirect Force Sensors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7333 Piezoelectric Strain Sensors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7334 Resistance Strain Gauges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7335 Customized Force Sensors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 734 Acceleration Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 735 Acoustic Emission Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 736 Sensor Comparisons
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 74 Signal Processing for Sensor-Based Tool Condition Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 741 Feature Extraction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7411 Time Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7412 Frequency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7413 Statistical Processing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7414 TimendashFrequency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 742 Feature Selection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 75 Wear ModelDecision-Making for Sensor-Based Tool Condition Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 751 Trending Threshold
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 752 Neural Networks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7521 Unsupervised Networks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7522 Supervised Networks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 753 Fuzzy Logic
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 754 Other Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 76 Conclusion
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53191ch8
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Chapter 8 Fault Diagnosis of Helicopter Gearboxes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 81 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 82 Abnormality Scaling
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 83 The Structure-Based Connectionist Network
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 84 Sensor Location Selection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 841 Coverage Index
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 842 Overlap Index
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 843 Monitoring Effectiveness
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 85 A Case Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 851 Structural and Featural Influences
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 852 Evaluation of Influences
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 853 Fault Detection Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 854 Fault Diagnostic Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 8541 Faulty Subsystem Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 8542 Faulty Component Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 855 Sensor Location Evaluation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 856 Sensor Location Validation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 86 Conclusion
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 53191ch9
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Chapter 9 Vibration Suppression and Monitoring in Precision Motion Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 91 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 92 Mechanical Design to Minimize Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 921 Stability and Static Determinacy of Machine Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 922 Two-Dimensional Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 923 Three-Dimensional Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 93 Adaptive Notch Filter
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 931 Fast Fourier Transform
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 932 Simulation and Experiments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 94 Real-Time Vibration Analyzer
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 941 Learning Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 942 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 943 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 944 Experiments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 9441 Input Variables mdash the Evaluation Criteria
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 94411 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 94412 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 9442 Evaluation Rules
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 94421 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 94422 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 9443 Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 94431 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 94432 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 95 Practical Insights and Case Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 96 Conclusions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 53191ch10
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Chapter 10 Vibration and Shock Problems of Civil Engineering Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 101 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 102 Earthquake-Induced Vibration of Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1021 Seismicity and Ground Motions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1022 Influence of Local Site Conditions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1023 Response of Structures to Ground Motions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1024 Dynamic Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10241 Equations of Motion for Linear Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10242 Equations of Motion for Linear Multiple-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1025 Earthquake Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10251 Elastic Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10252 Smoothed Design Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10253 Ductility-Modified Response Spectrum Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1026 Design Philosophy and the Code Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10261 Performance-Based Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1027 Analysis Options for Earthquake Effects
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10271 Dynamic Time History Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10272 Response Spectrum Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 102721 Response Spectrum Analysis of Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 102722 Response Spectrum Analysis of Multi-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10273 Equivalent Static Analysis (Force-Based Approach)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10274 Displacement-Based Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1028 SoilndashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1029 Active and Passive Control Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 10210 Worked Examples
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 103 Dynamic Effects of Wind Loading on Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1031 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1032 Wind Speed
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1033 Design Structures for Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10331 Types of Wind Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10332 Design Criteria
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10333 Static Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1034 Along and Across-Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10341 Along-Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10342 Across-Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1035 Wind Tunnel Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1036 Comfort Criteria Human Response to Building Motion
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1037 Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1038 Comparison with Earthquake Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 104 Vibrations Due to Fluid ndashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1041 Added Mass and Inertial Coupling
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1042 Wave-Induced Vibration of Structure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 105 Blast Loading and Blast Effects on Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1051 Explosions and Blast Phenomenon
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1052 Explosive Air-Blast Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10521 Blast Wave Scaling Laws
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10522 Prediction of Blast Pressure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1053 Gas Explosion Loading and Effect of Internal Explosions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1054 Structural Response to Blast Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10541 Elastic Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10542 Elasto-Plastic Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1055 Material Behaviors at High Strain Rate
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10551 Dynamic Properties of Concrete under High Strain Rates
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10552 Dynamic Properties of Reinforcing Steel under High Strain Rates
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1056 Failure Modes of Blast-Loaded Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10561 Global Structural Behavior
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10562 Localized Structural Behavior
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10563 PressurendashImpulse ( PndashI ) Diagrams
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1057 Blast WavendashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1058 Effect of Ground Shocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10581 Loads from Air-Induced Ground Shock
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10582 Loads from Direct Ground Shock
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1059 Technical Design Manuals for Blast-Resistant Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 10510 Computer Programs for Blast and Shock Effects
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 106 Impact Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1061 Structural Impact between Two Bodies mdash Hard Impact and Soft Impact
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1062 Example mdash Aircraft Impact
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 107 Floor Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1071 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1072 Types of Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10721 Walking
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10722 Rhythmic Activities
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10723 Mechanical Equipment
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10724 Analysis Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1073 Natural Frequency of Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10731 Computing the Natural Frequency
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10732 Computing Deflection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10733 Damping
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10734 Resonance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1074 Vibration Caused by Walking
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10741 Minimum Natural Frequency
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1075 Design for Rhythmic Excitation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10751 Harmonics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10752 Minimum Natural Frequency
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1076 Example mdash Vibration Analysis of a Reinforced Concrete Floor
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 53191ch11
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Chapter 11 Seismic Base Isolation and Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 111 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1111 From Ductility Design to Base Isolation and Control Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1112 The Importance of Reducing Seismic Input and Response
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 112 Seismic Base Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1121 Historical Development of Base Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1122 Basic Principle
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1123 Issues in Seismic Base Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11231 Performance Criteria
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11232 Type of Structure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11233 Site Characteristics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11234 Retrofit Issues
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11235 Design of Building Services
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11236 Expected Life of Isolator
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1124 Seismic Isolation Devices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11241 Laminated Rubber Bearings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11242 Lead Rubber Bearing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11243 Friction-Based Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11244 Other Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1125 Design of Isolation Devices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11251 High-Damping Rubber Bearing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112511 Stability against Buckling
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112512 Stability against Roll Out
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11252 Lead Rubber Bearings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112521 Design of Lead Plug
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112522 Design of Laminated Rubber Bearing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11253 Design of Friction Pendulum System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1126 Verification of Properties of Isolation Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11261 Tests for Isolation Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 112611 System Characterization Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 112612 Prototype Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 112613 Quality Control Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11262 Uniform Building Code Recommendations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112621 Units Dependent on Loading Rates
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112622 Units Dependent on Bilateral Load
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112623 System Adequacy
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1127 Analysis of Base-Isolated Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11271 Modeling of a Superstructure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11272 Modeling of Isolation System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11273 Static Analysis Procedure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11274 Dynamic Analysis Procedure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 112741 Response Spectrum Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 112742 Time-History Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11275 Software for Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1128 Experimental Methods for Isolated Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1129 Implementation of Seismic Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11291 New Construction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112911 Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112912 Bridges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11292 Seismic Retrofit
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112921 Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112922 Bridges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11293 Other Implementations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 11210 Performance during Past Earthquakes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 112101 Performance of Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 112102 Performance of Bridges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 113 Seismic Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1131 Historical Development of Seismic Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1132 Basic Principles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11321 Passive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11322 Active Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11323 Semiactive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11324 Hybrid Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11325 Categorization of Basic Principles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1133 Important Issues in Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11331 SoilndashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11332 DevicendashStructure Interaction and Time Delay
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11333 Design Guidelines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1134 Vibration-Control Devices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11341 Passive Control Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113411 Metallic Yielding Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113412 Friction Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113413 Viscoelastic Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113414 Viscous Fluid Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113415 Tuned Mass Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11342 Active Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113421 Electromagnetic Actuator
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113422 Hydraulic Actuators
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11343 Semiactive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113431 Variable-Orifice Hydraulic Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113432 Controllable Fluid Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113433 Controllable Friction Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11344 Hybrid Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1135 Control Algorithm
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11351 Active Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11352 Semiactive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113521 Common Control Schemes for Controllable Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113522 Special Control Schemes for Controllable Damper
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1136 Experimental Performance Verification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11361 Shaking Table Tests of a Flexible Structural Model with TMD AMD and ATMD
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11362 Substructure Hybrid Test
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113621 Hybrid Tests Using Hydraulic Actuator
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113622 Hybrid Tests Using Shaking Table
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113623 Hybrid Tests Using Inertia-Force-Driven Loading System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1137 Implementations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11371 Semiactive Control of Full-Scale Structures Using Variable Joint Damper System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113711 Background of Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113712 Test System Set Up
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113713 Control Algorithm
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113714 Test Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11372 Application of Structural Control Technologies to Seismic Retrofit of a Cable-Stayed Bridge
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113721 Background of Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113722 Basic Concept of Seismic Retrofit
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113723 Modal Shape Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113724 Time-History Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113725 Soil ndash Structure Interaction Effect
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113726 Semiactive Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53191ch12
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Chapter 12 Seismic Random Vibration of Long-Span Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 121 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1211 Basic Concepts of Random Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12111 Stationary Random Process
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12112 Nonstationary Random Process
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1212 Three Methods for Structural Seismic Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12121 Response Spectrum Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12122 Time-History Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12123 Random Vibration Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 121231 Davenport Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 121232 Vanmarcke Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 12124 Comparisons of the Three Seismic-Analysis Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 122 Seismic Random-Excitation Fields
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1221 Power Spectral Density of Spatially Varying Ground Acceleration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1222 Several Coherence Models
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12221 FengndashHu Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12222 Harichandran ndashVanmarcke Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12223 LohndashYeh Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12224 OliveirandashHaondashPenzien Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12225 LucondashWong Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12226 QundashWangndashWang Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1223 Generation of Ground Acceleration Power Spectral Density Curves from Acceleration Response Spectrum Curves
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12231 Kaul Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12232 Iteration Scheme
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1224 Seismic Equations of Motion of Long-Span Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1225 Seismic Waves and Their Geometrical Expressions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 123 Pseudoexcitation Method for Structural Random Vibration Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1231 Structures Subjected to Stationary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12311 Single Stationary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12312 Multiple Stationary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1232 Structures Subjected to Nonstationary Random Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12321 Structures Subjected to Uniformly Modulated Evolutionary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 123211 Single Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 123212 Multiple Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12322 Structures Subjected to Nonuniformly Modulated Evolutionary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 123221 Single Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 123222 Multiple Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1233 Precise Integration Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12331 Precise Integration of Exponential Matrices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12332 Particular Solutions and Precise Integration Formulas for Various Forms of Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 123321 Linear Loading Form (HPD-L Form)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 123322 Sinusoidal Loading Form (HPD-S Form)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 123323 Exponentially Decaying Sinusoidal Loading Form (HPD-E Form)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 124 Long-Span Structures Subjected to Stationary Random Ground Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1241 The Solution of Equations of Motion Using the Pseudoexcitation Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1242 Numerical Comparisons with Other Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12421 Song-Hua-Jiang Suspension Bridge
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 124211 All Supports Move Uniformly
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 124212 Wave Passage Effect Is Taken into Account
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 124213 Wave-Passage Effect and Incoherence Effect Are Jointly Taken into Account
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 12422 San Joaquin Concrete Bridge
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 125 Long-Span Structures Subjected to Nonstationary Random Ground Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1251 Modulation Functions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1252 The Formulas for Nonstationary Multiexcitation Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1253 Expected Extreme Values of Nonstationary Random Processes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1254 Numerical Comparisons with the Corresponding Stationary Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 126 Conclusions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 53191ch13
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Chapter 13 Seismic Qualification of Equipment
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 131 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 132 Distribution Qualification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1321 Drive-Signal Generation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1322 Distribution Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1323 Test Procedures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 133 Seismic Qualification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1331 Stages of Seismic Qualification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1332 Test Preliminaries
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1333 Single-Frequency Testing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1334 Multifrequency Testing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1335 Generation of RRS Specifications
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 53191ch14
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Chapter 14 Human Response to Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 141 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 142 Vibration Excitations on Humans
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1421 Excitation Characteristics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 143 Human Response to Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1431 Vibration Perception
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1432 Frequency Weighting Curve
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1433 Iso-Perception Curves
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1434 Detection Threshold Curve
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 144 Regulation of Human Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1441 Acceptable Vibration Levels in Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1442 Whole-Body Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1443 HandndashArm Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
Page 8: Vibration Monitoring, Testing, and Instrumentationpreview.kingborn.net › 646000 › d1a74678d91943e5ba1d5e... · The MEMS Handbook, Second Edition MEMS: Introduction and Fundamentals

Editor-in-Chief

Dr Clarence W de Silva PEng Fellow ASME Fellow IEEE Fellow Canadian Academy of

Engineering is Professor of Mechanical Engineering at the University of British Columbia Vancouver

Canada and has occupied the NSERC-BC Packers Research Chair in Industrial Automation since 1988

He has earned PhD degrees from the Massachusetts Institute of Technology and the University of

Cambridge England De Silva has also occupied the Mobil Endowed Chair Professorship in the

Department of Electrical and Computer Engineering at the National University of Singapore He has

served as a consultant to several companies including IBM and Westinghouse in US and has led the

development of eight industrial machines and devices He is recipient of the Henry M Paynter

Outstanding Investigator Award from the Dynamic Systems and Control Division of the American

Society of Mechanical Engineers (ASME) Killam Research Prize Lifetime Achievement Award from the

World Automation Congress Outstanding Engineering Educator Award of IEEE Canada Yasundo

Takahashi Education Award of the Dynamic Systems and Control Division of ASME IEEE Third

Millennium Medal Meritorious Achievement Award of the Association of Professional Engineers of BC

and the Outstanding Contribution Award of the Systems Man and Cybernetics Society of the Institute

of Electrical and Electronics Engineers (IEEE)

He has authored 16 technical books including Sensors and Actuators Control System Instrumentation

(Taylor amp Francis CRC Press 2007) MechatronicsmdashAn Integrated Approach (Taylor amp Francis CRC

Press Boca Raton FL 2005) Soft Computing and Intelligent Systems DesignmdashTheory Tools and

Applications (with F Karry Addison Wesley New York NY 2004) VIBRATION Fundamentals and

Practice (Taylor amp Francis CRC Press 2nd edition 2006) INTELLIGENT CONTROL Fuzzy Logic

Applications (Taylor amp Francis CRC Press 1995) Control Sensors and Actuators (Prentice Hall 1989) 14

edited volumes over 170 journal papers 200 conference papers and 12 book chapters He has served on

the editorial boards of 14 international journals in particular as the Editor-in-Chief of the International

Journal of Control and Intelligent Systems Editor-in-Chief of the International Journal of Knowledge-Based

Intelligent Engineering Systems Senior Technical Editor of Measurements and Control and Regional

Editor North America of Engineering Applications of Artificial Intelligence ndash the International Journal of

Intelligent Real-Time Automation He is a Lilly Fellow at Carnegie Mellon University NASA-ASEE Fellow

Senior Fulbright Fellow at Cambridge University ASI Fellow and a Killam Fellow Research and

development activities of Professor de Silva are primarily centered in the areas of process automation

robotics mechatronics intelligent control and sensors and actuators with cash funding of about $6

million as principal investigator

ix

53191mdash1432007mdash1850mdashVELUmdash246493mdash CRC ndash pp 1ndash15

copy 2007 by Taylor amp Francis Group LLC

Contributors

xi

Kourosh DanaiUniversity of Massachusetts

Amherst Massachusetts

Clarence W de SilvaThe University of British Columbia

Vancouver British Columbia Canada

P S HeynsUniversity of Pretoria

Pretoria South Africa

S HuangNational University of Singapore

Singapore

Hirokazu IemuraKyoto University

Kyoto Japan

Sarvesh Kumar JainMadhav Institute of Technology and

Science

Madhya Pradesh India

Christian LalanneEngineering Consultant

Jalles France

TH LeeNational University of Singapore

Singapore

YP LeowSingapore Institute of Manufacturing

Technology

Singapore

SY LimSingapore Institute of Manufacturing

Technology

Singapore

Jiaohao LinDalian University of Technology

Liaoning Peoplersquos Republic of China

W LinSingapore Institute of Manufacturing

Technology

Singapore

Chris K MechefskeQueenrsquos University

Kingston Ontario Canada

Priyan MendisUniversity of Melbourne

Melbourne Victoria Australia

Tuan NgoUniversity of Melbourne

Melbourne Victoria Australia

Mulyo Harris PradonoKyoto University

Kyoto Japan

C SchefferUniversity of Stellenbosch

Pretoria South Africa

KK TanNational University of Singapore

Singapore

KZ TangNational University of Singapore

Singapore

Yahui ZhangDalian University of Technology

Liaoning Peoplersquos Republic of China

53191mdash1432007mdash1850mdashVELUmdash246493mdash CRC ndash pp 1ndash15

copy 2007 by Taylor amp Francis Group LLC

Contents

1 Vibration Instrumentation Clarence W de Silva 1-1

11 Introduction 1-1

12 Vibration Exciters 1-3

13 Control System 1-15

14 Performance Specification 1-21

15 Motion Sensors and Transducers 1-27

16 Torque Force and Other Sensors 1-50

Appendix 1A Virtual Instrumentation for Data Acquisition Analysis

and Presentation 1-73

2 Signal Conditioning and Modification Clarence W de Silva 2-1

21 Introduction 2-2

22 Amplifiers 2-2

23 Analog Filters 2-15

24 Modulators and Demodulators 2-29

25 AnalogndashDigital Conversion 2-37

26 Bridge Circuits 2-43

27 Linearizing Devices 2-49

28 Miscellaneous Signal Modification Circuitry 2-56

29 Signal Analyzers and Display Devices 2-62

3 Vibration Testing Clarence W de Silva 3-1

31 Introduction 3-1

32 Representation of a Vibration Environment 3-3

33 Pretest Procedures 3-24

34 Testing Procedures 3-37

35 Some Practical Information 3-52

4 Experimental Modal Analysis Clarence W de Silva 4-1

41 Introduction 4-1

42 Frequency-Domain Formulation 4-2

43 Experimental Model Development 4-8

44 Curve Fitting of Transfer Functions 4-10

45 Laboratory Experiments 4-18

46 Commercial EMA Systems 4-24

xiii

53191mdash1432007mdash1850mdashVELUmdash246493mdash CRC ndash pp 1ndash15

copy 2007 by Taylor amp Francis Group LLC

5 Mechanical Shock Christian Lalanne 5-1

51 Definitions 5-2

52 Description in the Time Domain 5-3

53 Shock Response Spectrum 5-4

54 Pyroshocks 5-17

55 Use of Shock Response Spectra 5-18

56 Standards 5-24

57 Damage Boundary Curve 5-26

58 Shock Machines 5-28

59 Generation of Shock Using Shakers 5-44

510 Control by a Shock Response Spectrum 5-52

511 Pyrotechnic Shock Simulation 5-58

6 Machine Condition Monitoring and Fault Diagnostics Chris K Mechefske 6-1

61 Introduction 6-2

62 Machinery Failure 6-2

63 Basic Maintenance Strategies 6-4

64 Factors Which Influence Maintenance Strategy 6-7

65 Machine Condition Monitoring 6-8

66 Transducer Selection 6-10

67 Transducer Location 6-14

68 Recording and Analysis Instrumentation 6-14

69 Display Formats and Analysis Tools 6-16

610 Fault Detection 6-21

611 Fault Diagnostics 6-25

7 Vibration-Based Tool Condition Monitoring Systems C Scheffer and PS Heyns 7-1

71 Introduction 7-1

72 Mechanics of Turning 7-2

73 Vibration Signal Recording 7-7

74 Signal Processing for Sensor-Based Tool Condition Monitoring 7-11

75 Wear ModelDecision-Making for Sensor-Based Tool Condition Monitoring 7-15

76 Conclusion 7-20

8 Fault Diagnosis of Helicopter Gearboxes Kourosh Danai 8-1

81 Introduction 8-1

82 Abnormality Scaling 8-5

83 The Structure-Based Connectionist Network 8-8

84 Sensor Location Selection 8-11

85 A Case Study 8-14

86 Conclusion 8-23

9 Vibration Suppression and Monitoring in Precision Motion Systems KK Tan

TH Lee KZ Tang S Huang SY Lim W Lin and YP Leow 9-1

91 Introduction 9-1

92 Mechanical Design to Minimize Vibration 9-2

93 Adaptive Notch Filter 9-10

94 Real-Time Vibration Analyzer 9-17

Contentsxiv

53191mdash1432007mdash1850mdashVELUmdash246493mdash CRC ndash pp 1ndash15

copy 2007 by Taylor amp Francis Group LLC

95 Practical Insights and Case Study 9-29

96 Conclusions 9-35

10 Vibration and Shock Problems of Civil Engineering Structures Priyan Mendis

and Tuan Ngo 10-1

101 Introduction 10-2

102 Earthquake-Induced Vibration of Structures 10-3

103 Dynamic Effects of Wind Loading on Structures 10-22

104 Vibrations Due to FluidndashStructure Interaction 10-33

105 Blast Loading and Blast Effects on Structures 10-34

106 Impact Loading 10-47

107 Floor Vibration 10-51

11 Seismic Base Isolation and Vibration Control Hirokazu Iemura Sarvesh Kumar Jain

and Mulyo Harris Pradono 11-1

111 Introduction 11-1

112 Seismic Base Isolation 11-4

113 Seismic Vibration Control 11-33

12 Seismic Random Vibration of Long-Span Structures Jiahao Lin and Yahui Zhang 12-1

121 Introduction 12-2

122 Seismic Random-Excitation Fields 12-11

123 Pseudoexcitation Method for Structural Random Vibration Analysis 12-16

124 Long-Span Structures Subjected to Stationary Random Ground Excitations 12-27

125 Long-Span Structures Subjected to Nonstationary Random Ground Excitations 12-34

126 Conclusions 12-39

13 Seismic Qualification of Equipment Clarence W de Silva 13-1

131 Introduction 13-1

132 Distribution Qualification 13-1

133 Seismic Qualification 13-6

14 Human Response to Vibration Clarence W de Silva 14-1

141 Introduction 14-1

142 Vibration Excitations on Humans 14-2

143 Human Response to Vibration 14-3

144 Regulation of Human Vibration 14-6

Contents xv

53191mdash1432007mdash1850mdashVELUmdash246493mdash CRC ndash pp 1ndash15

copy 2007 by Taylor amp Francis Group LLC

1Vibration

Instrumentation

Clarence W de SilvaThe University of British Columbia

11 Introduction 1-1

12 Vibration Exciters 1-3Shaker Selection dagger Dynamics of Electromagnetic Shakers

13 Control System 1-15Components of a Shaker Controller dagger Signal-Generating

Equipment

14 Performance Specification 1-21Parameters for Performance Specification dagger Linearity dagger

Instrument Ratings dagger Accuracy and Precision

15 Motion Sensors and Transducers 1-27Potentiometer dagger Variable-Inductance Transducers dagger

Mutual-Induction Proximity Sensor dagger Selfinduction

Transducers dagger Permanent-Magnet Transducers dagger

Alternating Current Permanent-Magnet Tachometer dagger

Alternating Current Induction Tachometer dagger Eddy Current

Transducers dagger Variable-Capacitance Transducers dagger

Piezoelectric Transducers

16 Torque Force and Other Sensors 1-50Strain Gage Sensors dagger Miscellaneous Sensors

Appendix 1A Virtual Instrumentation for DataAcquisition Analysis and Presentation 1-73

Summary

Devices useful in instrumenting a mechanical vibrating system are presented in this chapter Shakers whichgenerate vibration excitations are discussed and compared A variety of sensors including motion sensorsproximity sensors forcetorque sensors and other miscellaneous sensors are considered Performance specificationin the time domain and the frequency domain is addressed Rating parameters of instruments are given

11 Introduction

Measurement and associated experimental techniques play a significant role in the practice of vibration

Academic exposure to vibration instrumentation usually arises in laboratories in the context of learning

training and research In vibration practice perhaps the most important task of instrumentation is the

measurement or sensing of vibration Vibration sensing is useful in the following applications

1 Design and development of a product

2 Testing (screening) of a finished product for quality assurance

3 Qualification of a good-quality product to determine its suitability for a specific application

1-1

53191mdash522007mdash1201mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

4 Mechanical aging of a product prior to carrying out a test program

5 Exploratory testing of a product to determine its dynamic characteristics such as resonances

mode shapes and even a complete dynamic model

6 Vibration monitoring for performance evaluation

7 Control and suppression of vibration

Figure 11 indicates a procedure typical of experimental vibration highlighting the essential

instrumentation Vibrations are generated in a device the test object in response to some excitation In

some experimental procedures primarily in vibration testing (see Figure 11) the excitation signal has

to be generated in a signal generator in accordance with some requirement (specification) and applied to

the object through an exciter after amplification and conditioning In some other situations primarily in

performance monitoring and vibration control the excitations are generated as an integral part of the

operating environment of the vibrating object and may originate either within the object (eg engine

excitations in an automobile) or in the environment with which the object interacts during operation

(eg road disturbances on an automobile) Sensors are needed to measure vibrations in the test object In

particular a control sensor is used to check whether the specified excitation is applied to the object

and one or more response sensors may be used to measure the resulting vibrations at key locations of

the object

The sensor signals have to be properly conditioned for example by filtering and amplification and

modified for example through modulation demodulation and analog-to-digital conversion prior to

recording analyzing and display The purpose of the controller is to guarantee that the excitation is

correctly applied to the test object If the signal from the control sensor deviates from the required

excitation the controller modifies the signal to the exciter so as to reduce this deviation Furthermore the

controller will stabilize or limit (compress) the vibrations in the object It follows that instruments in

experimental vibration may be generally classified into the following categories

1 Signal-generating devices

2 Vibration exciters

3 Sensors and transducers

4 Signal conditioningmodifying devices

5 Signal analysis devices

6 Control devices

7 Vibration recording and display devices

AnalogDigital

Interface

DigitalSignal

RecorderAnalyzerDisplay

FilterAmplifier

FilterAmplifier

SignalGenerator

and ExciterController

Reference (Required)Signal (Specification)

PowerAmplifier

MountingFixtures

TestObject

ResponseSensor

ControlSensor

Exciter

SwivelBase

FIGURE 11 Typical instrumentation in experimental vibration

Vibration Monitoring Testing and Instrumentation1-2

53191mdash522007mdash1201mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

Note that one instrument may perform the tasks

of more than one category listed here Also more

than one instrument may be needed to carry out

tasks in a single category In the following sections

we will provide some examples of the types of

vibration instrumentation giving characteristics

operating principles and important practical

considerations Also we will describe several

experiments which can be found in a typical

vibration laboratory

An experimental vibration system generally

consists of four main subsystems

1 Test object

2 Excitation system

3 Control system

4 Signal acquisition and modification system

These are schematically shown in Figure 12 Note that various components shown in Figure 11 may

be incorporated into one of these subsystems In particular component matching hardware and object

mounting fixtures may be considered interfacing devices that are introduced through the interaction

between the main subsystems as shown in Figure 12 Some important issues of vibration testing and

instrumentation are summarized in Box 11

12 Vibration Exciters

Vibration experimentation may require an external exciter to generate the necessary vibration This is the

case in controlled experiments such as product testing where a specified level of vibration is applied to the

test object and the resulting response is monitored A variety of vibration exciters are available with

different capabilities and principles of operation

Three basic types of vibration exciters (shakers) are widely used hydraulic shakers inertial shakers

and electromagnetic shakers The operation-capability ranges of typical exciters in these three categories

are summarized in Table 11 Stroke or maximum displacement is the largest displacement the exciter

is capable of imparting onto a test object whose weight is assumed to be within its design load limit

Maximum velocity and acceleration are similarly defined Maximum force is the largest force that could

be applied by the shaker to a test object of acceptable weight (one within the design load) The values

given in Table 11 should be interpreted with caution Maximum displacement is achieved only at very

low frequencies The achievement of maximum velocity corresponds to intermediate frequencies in the

operating frequency range of the shaker Maximum acceleration and force ratings are usually achieved at

high frequencies It is not feasible for example to operate a vibration exciter at its maximum

displacement and its maximum acceleration simultaneously

Consider a loaded exciter that is executing harmonic motion Its displacement is given by

x frac14 s sin vt eth11THORN

in which s is the displacement amplitude (or stroke) Corresponding velocity and acceleration are

_x frac14 sv cos vt eth12THORN

eurox frac14 2sv2sin vt eth13THORN

SignalModification

System

TestObject

ControlSystem

VibrationExciter (Shaker)

System

FIGURE 12 Interactions between major subsystems of

an experimental vibration system

Vibration Instrumentation 1-3

53191mdash522007mdash1201mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

If the velocity amplitude is denoted by v and the acceleration amplitude by a it follows from Equation

12 and Equation 13 thatv frac14 vs eth14THORN

and

a frac14 vv eth15THORN

Box 11

VIBRATION INSTRUMENTATION

Vibration Testing Applications for Products

Design and Development Production Screening and Quality Assessment Utilization and Qualification for Special Applications

Testing Instrumentation

Exciter (excites the test object) Controller (controls the exciter for accurate excitation) Sensors and Transducers (measure excitations and responses and provide excitation error

signals to controller) Signal Conditioning (converts signals to appropriate form) Recording and Display (perform processing storage and documentation)

Exciters

Shakers

1 Electrodynamic (high bandwidth moderate power complex and multifrequency

excitations)

2 Hydraulic (moderate to high bandwidth high power complex and multifrequency

excitations)

3 Inertial (low bandwidth low power single-frequency harmonic excitations)

TransientInitial Condition

1 Hammers (impulsive bump tests)

2 Cable Release (step excitations)

3 Drop (impulsive)

Signal Conditioning

Filters Amplifiers Amplifiers ModulatorsDemodulators ADCDAC

Sensors

Motion (displacement velocity acceleration) Force (strain torque)

Vibration Monitoring Testing and Instrumentation1-4

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copy 2007 by Taylor amp Francis Group LLC

TABLE 11 Typical Operation-Capability Ranges for Various Shaker Types

Shaker Type Typical Operational Capabilities

Frequency Maximum Displacement

(Stroke)

Maximum

Velocity

Maximum

Acceleration

Maximum

Force

Excitation

Waveform

Hydraulic

(electrohydraulic)

Low

(01ndash500 Hz)

High (20 in 50 cm) Intermediate

(50 insec

125 cmsec)

Intermediate

(20 g)

High (100000 lbf

450000 N)

Average flexibility (simple

to complex and random)

Inertial

(counter-rotating mass)

Intermediate

(2ndash50 Hz)

Low (1 in 25 cm) Intermediate

(50 insec

125 cmsec)

Intermediate

(20 g)

Intermediate

(1000 lbf 4500 N)

Sinusoidal only

Electromagnetic

(electrodynamic)

High

(2ndash10000 Hz)

Low (1 in 25 cm) Intermediate

(50 insec

125 cmsec)

High (100 g) Low to intermediate

(450 lbf 2000 N)

High flexibility and accuracy

(simple to complex and

random)

VibrationInstru

mentation

1-5

53191mdash522007mdash

1201mdashSENTHILKUMARmdash246494mdash

CRCndashpp1ndash112

copy 2007 by Taylor amp Francis Group LLC

An idealized performance curve of a shaker

has a constant displacementndashamplitude region a

constant velocityndashamplitude region and a con-

stant accelerationndashamplitude region for low

intermediate and high frequencies respectively

in the operating frequency range Such an ideal

performance curve is shown in Figure 13(a) on a

frequencyndashvelocity plane Logarithmic axes are

used In practice typical shaker performance

curves would be fairly smooth yet nonlinear

curves similar to those shown in Figure 13(b)

As the mass increases the performance curve

compresses Note that the acceleration limit of a

shaker depends on the mass of the test object

(load) Full load corresponds to the heaviest object

that could be tested The ldquono loadrdquo condition

corresponds to a shaker without a test object To

standardize the performance curves they are

usually defined at the rated load of the shaker A

performance curve in the frequencyndashvelocity

plane may be converted to a curve in the

frequencyndashacceleration plane simply by increasing

the slope of the curve by a unit magnitude (ie

20 dbdecade)

Several general observations can be made from

Equation 14 and Equation 15 In the constant-

peak displacement region of the performance

curve the peak velocity increases proportionally

with the excitation frequency and the peak

acceleration increases with the square of the excitation frequency In the constant-peak velocity region

the peak displacement varies inversely with the excitation frequency and the peak acceleration increases

proportionately In the constant-peak acceleration region the peak displacement varies inversely with the

square of the excitation frequency and the peak velocity varies inversely with the excitation frequency

This further explains why rated stroke maximum velocity and maximum acceleration values are not

simultaneously realized

121 Shaker Selection

Vibration testing is accomplished by applying a specified excitation to the test package using a shaker

apparatus and monitoring the response of the test object Test excitation may be represented by its

response spectrum The test requires that the response spectrum of the actual excitation known as the

test response spectrum (TRS) envelops the response spectrum specified for the particular test known as

the required response spectrum (RRS)

A major step in the planning of any vibration testing program is the selection of a proper shaker

(exciter) system for a given test package The three specifications that are of primary importance in

selecting a shaker are the force rating the power rating and the stroke (maximum displacement) rating

Force and power ratings are particularly useful in moderate to high frequency excitations and the stroke

rating is the determining factor for low frequency excitations In this section a procedure is given to

determine conservative estimates for these parameters in a specified test for a given test package

Frequency domain considerations are used here

Stroke

Limit M

ax

Acceleration

MaxVelocity

Peak

Vel

ocity

(cm

s)

01 1 10 100

FullLoad

NoLoad

Frequency (Hz)(a)

Peak

Vel

ocity

(cm

s)

100

10

1

100

10

1

01 1 10 100

FullLoad

NoLoad

Frequency (Hz)(b)

FIGURE 13 Performance curve of a vibration exciter

in the frequencyndashvelocity plane (log) (a) ideal (b)

typical

Vibration Monitoring Testing and Instrumentation1-6

53191mdash522007mdash1201mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

1211 Force Rating

In the frequency domain the (complex) force at the exciter (shaker) head is given by

F frac14 mHethvTHORNasethvTHORN eth16THORNin which v is the excitation frequency variable m is the total mass of the test package including

mounting fixture and attachments asethvTHORN is the Fourier spectrum of the support-location (exciter head)

acceleration and H(v) is frequency response function that takes into account the flexibility and

damping effects (dynamics) of the test package apart from its inertia In the simplified case where the

test package can be represented by a simple oscillator of natural frequency vn and damping ratio by zt

this function becomes

HethvTHORN frac14 1thorn 2jztv=vn=12 ethv=vnTHORN2 thorn 2jztv=vn eth17THORNin which j frac14 ffiffiffiffi

21p

This approximation is adequate for most practical purposes The static weight of the

test object is not included in Equation 16 Most heavy-duty shakers which are typically hydraulic

have static load support systems such as pneumatic cushion arrangements that can exactly balance the

dead load The exciter provides only the dynamic force In cases where shaker directly supports the

gravity load in the vertical test configuration Equation 16 should be modified by adding a term to

represent this weight

A common practice in vibration test applications is to specify the excitation signal by its response

spectrum This is simply the peak response of a simple oscillator expressed as a function of its natural

frequency when its support location is excited by the specified signal Clearly the damping of the simple

oscillator is an added parameter in a response spectrum specification Typical damping ratios ethzrTHORN used inresponse spectra specifications are less than 01 (or 10) It follows that an approximate relationship

between the Fourier spectrum of the support acceleration and its response spectrum is

as frac14 2jzrarethvTHORN eth18THORNThe magnitude larethvTHORNl is the response spectrumEquation 18 substituted into Equation 16 gives

F frac14 mHethvTHORN2jzrarethvTHORN eth19THORNIn view of Equation 17 for test packages having low damping the peak value of H(v) is

approximately 1=eth2jztTHORN this should be used in computing the force rating if the test package has a

resonance within the frequency range of testing On the other hand if the test package is assumed to be

rigid then HethvTHORN oslash 1 A conservative estimate for the force rating is

Fmax frac14 methzr=ztTHORNlarethvTHORNlmax eth110THORNIt should be noted that larethvTHORNlmax is the peak value of the specified (required) response spectrum (RRS)

for acceleration

1212 Power Rating

The exciter head does not develop its maximum force when driven at maximum velocity Output power

is determined by using

p frac14 Refrac12FvsethvTHORN eth111THORNin which vsethvTHORN is the Fourier spectrum of the exciter velocity and Re [ ] denotes the real part of a complex

function Note that as frac14 jvvs Substituting Equation 16 and Equation 18 into Equation 111 gives

p frac14 eth4mz2r =vTHORNRefrac12jHethvTHORNa2r ethvTHORN eth112THORNIt follows that a conservative estimate for the power rating is

pmax frac14 2methz2r =ztTHORNfrac12larethvTHORNl2=v max eth113THORN

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Representative segments of typical acceleration RRS curves have slope n as given by

a frac14 k1vn eth114THORN

It should be clear from Equation 113 that the maximum output power is given by

pmax frac14 k2v2n21 eth115THORN

This is an increasing function for n 1=2 and a decreasing function for n 1=2 It follows that the power

rating corresponds to the highest point of contact between the acceleration RRS curve and a line of slope

equal to 12 A similar relationship may be derived if velocity RRS curves (having slopes n2 1) are used

1213 Stroke Rating

From Equation 18 it should be clear that the Fourier spectrum xs of the exciter displacement time

history can be expressed as

xs frac14 2zrarethvTHORN=jv2 eth116THORNAn estimate for stroke rating is

xmax frac14 2zrfrac12larethvTHORNl=v2 max eth117THORNThis is of the form

xmax frac14 kvn22 eth118THORNIt follows that the stroke rating corresponds to the highest point of contact between the acceleration

RRS curve and a line of slope equal to two

Example 11

A test package of overall mass 100 kg is to be

subjected to dynamic excitation represented by the

acceleration RRS (at 5 damping) as shown in

Figure 14 The estimated damping of the test

package is 7 The test package is known to have a

resonance within the frequency range of the

specified test Determine the exciter specifications

for the test

Solution

From the development presented in the previous

section it is clear that the point F (or P) in

Figure 14 corresponds to the force and output

power ratings and the point S corresponds to

the stroke rating The co-ordinates of these

critical points are F P frac14 eth42 Hz 40 gTHORN and S frac14 eth08 Hz 075 gTHORN Equation 110 gives the force

rating as

Fmax frac14 100 pound eth005=007THORN pound 40 pound 981 N frac14 2803 N

Equation 113 gives the power rating as

pmax frac14 2 pound 100 pound eth0052=007THORN pound frac12eth40 pound 981THORN2=42 pound 2p watts frac14 417 W

Equation 117 gives the stroke rating as

xmax frac14 2 pound 005 pound frac12eth075 pound 98THORN=eth08 pound 2pTHORN2 m frac14 3 cm

Acc

eler

atio

n(g

)

Con

stan

t Dis

plac

emen

t

Constant Velo

city

Frequency (Hz)

S

FP

0101

10 10 100

10

10

FIGURE 14 Test excitation specified by an accelera-

tion RRS (5 damping)

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1214 Hydraulic Shakers

A typical hydraulic shaker consists of a piston-cylinder arrangement (also called a ram) a servo-valve a

fluid pump and a driving electric motor Hydraulic fluid (oil) is pressurized (typical operating pressure

4000 psi) and pumped into the cylinder through a servo-valve by means of a pump that is driven by an

electric motor (typical power 150 hp) The flow (typical rate 100 galmin) that enters the cylinder is

controlled (modulated) by the servo-valve which in effect controls the resulting piston (ram) motion

A typical servo-valve consists of a two-stage spool valve which provides a pressure difference and a

controlled (modulated) flow to the piston which sets it in motion

The servo-valve itself is moved by means of a linear torque motor which is driven by the excitation-

input signal (electrical) A primary function of the servo-valve is to provide a stabilizing feedback to the

ram In this respect the servo-valve complements the main control system of the test setup The ram is

coupled to the shaker table by means of a link with some flexibility The cylinder frame is mounted on the

support foundation with swivel joints This allows for some angular and lateral misalignment which

might be caused primarily by test-object dynamics as the table moves

Two-degree-of-freedom (Two-DoF) testing requires two independent sets of actuators and three-DoF

testing requires three independent actuator sets Each independent actuator set can consist of several

actuators operated in parallel using the same pump and the same excitation-input signal to the torque

motors

If the test table is directly supported on the vertical actuators they must withstand the total dead

weight (ie the weight of the test table the test object the mounting fixtures and the instrumentation)

This is requirement is usually prevented by providing a pressurized air cushion in the gap between the

test table and the foundation walls Air should be pressurized so as to balance the total dead weight

exactly (typical required gage pressure 3 psi)

Figure 15(a) shows the basic components of a typical hydraulic shaker The corresponding

operational block diagram is shown in Figure 15(b) It is desirable to locate the actuators in a pit in the

test laboratory so that the test tabletop is flushed with the test laboratory floor under no-load conditions

This minimizes the effort required to place the test object on the test table Otherwise the test object has

to be lifted onto the test table with a forklift Also installation of an aircushion to support the system

dead weight is difficult under these circumstances of elevated mounting

Hydraulic actuators are most suitable for heavy load testing and are widely used in industrial and civil

engineering applications They canbeoperated at very low frequencies (almost direct current [DC]) aswell

as at intermediate frequencies (see Table 11) Large displacements (stroke) are possible at low frequencies

Hydraulic shakers have the advantage of providing high flexibility of operation during the test their

capabilities include variable-force and constant-force testing and wide-band random-input testing The

velocity and acceleration capabilities of hydraulic shakers are moderate Although any general excitation-

input motion (for example sine wave sine beat wide-band random) can be used in hydraulic shakers

faithful reproduction of these signals is virtually impossible at high frequencies because of distortion and

higher-order harmonics introduced by the high noise levels that are common in hydraulic systems This

is only a minor drawback in heavy-duty intermediate-frequency applications Dynamic interactions are

reduced through feedback control

1215 Inertial Shakers

In inertial shakers or ldquomechanical excitersrdquo the force that causes the shaker-table motion is generated by

inertia forces (accelerating masses) Counter-rotating-mass inertial shakers are typical in this category

To understand their principle of operation consider two equal masses rotating in opposite directions at

the same angular speed v and in the same circle of radius r (see Figure 16) This produces a resultant

force equal to 2mv2r cos vt in a fixed direction (the direction of symmetry of the two rotating arms)

Consequently a sinusoidal force with a frequency of v and an amplitude proportional to v2 is generated

This reaction force is applied to the shaker table

Figure 17 shows a sketch of a typical counter-rotating-mass inertial shaker It consists of two identical

rods rotating at the same speed in opposite directions Each rod has a series of slots in which to

Vibration Instrumentation 1-9

53191mdash522007mdash1201mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

place weights In this manner the magnitude of

the eccentric mass can be varied to achieve various

force capabilities The rods are driven by a

variable-speed electric motor through a gear

mechanism that usually provides several speed

ratios A speed ratio is selected depending on the

required test-frequency range The whole system is

symmetrically supported on a carriage that is

directly connected to the test table The test object

is mounted on the test table The preferred

mounting configuration is horizontal so that the

excitation force is applied to the test object in a

horizontal direction In this configuration there

are no variable gravity moments (weight pounddistance to center of gravity) acting on the drive

mechanism Figure 17 shows the vertical con-

figuration In dynamic testing of large structures

the carriage can be mounted directly on the

structure at a location where the excitation force

should be applied By incorporating two pairs of

counter-rotating masses it is possible to generate

test moments as well as test forces

FIGURE 15 A typical hydraulic shaker arrangement (a) schematic diagram (b) operational block diagram

m m

2mw2r cos wt

wtw w

wt

FIGURE 16 Principle of operation of a counter-

rotating-mass inertial shaker

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Reaction-type shakers driven by inertia are widely used for the prototype testing of civil engineering

structures Their first application dates back to 1935 Inertial shakers are capable of producing

intermediate excitation forces The force generated is limited by the strength of the carriage frame The

frequency range of operation and the maximum velocity and acceleration capabilities are also

intermediate for inertial shakers whereas the maximum displacement capability is typically low A major

limitation of inertial shakers is that their excitation force is exclusively sinusoidal and that the force

amplitude is directly proportional to the square of the excitation frequency As a result complex and

random excitation testing constant-force testing (for example transmissibility tests and constant-force

sine-sweep tests) and flexibility to vary the force amplitude or the displacement amplitude during a test

are not generally feasible with this type of shakers Excitation frequency and amplitude can be varied

during testing however by incorporating a variable-speed drive for the motor The sinusoidal excitation

generated by inertial shakers is virtually undistorted which gives them an advantage over the other types

of shakers when used in sine-dwell and sine-sweep tests Small portable shakers with low-force capability

are available for use in on-site testing

1216 Electromagnetic Shakers

In electromagnetic shakers or ldquoelectrodynamic excitersrdquo the motion is generated using the principle of

operation of an electric motor Specifically the excitation force is produced when a variable excitation

signal (electrical) is passed through a moving coil placed in a magnetic field

The components of a commercial electromagnetic shaker are shown in Figure 18 A steady magnetic

field is generated by a stationary electromagnet that consists of field coils wound on a ferromagnetic base

that is rigidly attached to a protective shell structure The shaker head has a coil wound around it When

the excitation electrical signal is passed through this drive coil the shaker head which is supported on

flexure mounts will be set in motion The shaker head consists of the test table on which the test object

is mounted Shakers with interchangeable heads are available The choice of appropriate shaker head is

based on the geometry and mounting features of the test object The shaker head can be turned to

different angles by means of a swivel joint In this manner different directions of excitation (in biaxial

and triaxial testing) can be obtained

FIGURE 17 Sketch of a counter-rotating-mass inertial shaker

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copy 2007 by Taylor amp Francis Group LLC

122 Dynamics of Electromagnetic Shakers

Consider a single axis electromagnetic shaker (Figure 18) with a test object having a single natural

frequency of importance within the test frequency range The dynamic interactions between the shaker

and the test object give rise to two significant natural frequencies (and correspondingly two significant

resonances) These appear as peaks in the frequency response curve of the test setup Furthermore the

natural frequency (resonance) of the test package alone causes a ldquotroughrdquo or depression (antiresonance)

in the frequency response curve of the overall test setup To explain this characteristic consider the

dynamic model shown in Figure 19 The following mechanical parameters are defined for

Figure 19(a) m k and b are the mass stiffness and equivalent viscous damping constant respectively

of the test package and me ke and be are the corresponding parameters of the exciter (shaker) Also in

the equivalent electrical circuit of the shaker head as shown in Figure 19(b) the following electrical

parameters are defined Re and Le are the resistance and (leakage) inductance and kb is the back

electromotive force (back emf) of the linear motor Assuming that the gravitational forces are supported

FIGURE 18 Schematic sectional view of a typical electromagnetic shaker manufactured by Bruel and Kjaer

Denmark

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copy 2007 by Taylor amp Francis Group LLC

by the static deflections of the flexible elements and that the displacements are measured from the static

equilibrium position we have the following system equations

Test object meuroy frac14 2kethy2 yeTHORN2 beth_y2 _yeTHORN eth119THORNShaker head me euroye frac14 fe thorn kethy2 yeTHORN thorn beth_y2 _yeTHORN2 key 2 be _ye eth120THORN

Electrical Lediedt

thorn Reie thorn kb _ye frac14 vethtTHORN eth121THORN

The electromagnetic force fe generated in the shaker head is a result of the interaction of the magnetic

field generated by the current ie with coil of the moving shaker head and the constant magnetic field

(stator) in which the head coil is located Here we have

fe frac14 kbie eth122THORNNote that v(t) is the voltage signal that is applied by the amplifier to the shaker coil ye is the displacement

of the shaker head and y is the displacement response of the test package

It is assumed that kb has consistent electrical and mechanical units (Vmsec and NA) Usually

the electrical time constant of the shaker is quite small compared with the primarily mechanical

time constants of the shaker and the test package In such cases the Ledie=dt term in Equation 121 may

be neglected Consequently the equations from Equation 119 through Equation 122 may be

expressed in the Laplace (frequency) domain with the Laplace variable s taking the place of the derivative

d=dt as

ethms2 thorn bsthorn kTHORNy frac14 ethbsthorn kTHORNye eth123THORN

FIGURE 19 Dynamic models of an electromagnetic shaker and a flexible test package (a) mechanical model

(b) electrical model

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copy 2007 by Taylor amp Francis Group LLC

frac12mes2 thorn ethbthorn beTHORNsthorn ethkthorn keTHORN ye frac14 ethbsthorn kTHORNy thorn kb

Rev2

k2bs

Reye eth124THORN

It follows that the transfer function of the shaker head motion with respect to the excitation voltage is

given by

yevfrac14 kb

Re

DethsTHORNDdethsTHORN eth125THORN

where DethsTHORN is the characteristic function of the primary dynamics of the test object

DethsTHORN frac14 ms2 thorn bsthorn k eth126THORN

and DdethsTHORN is the characteristic function of the primary dynamic interactions between the shaker and thetest object

DcethsTHORN frac14 mmes4 thorn frac12methbe thorn bthorn boTHORN thornmeb s

3 thorn frac12methke thorn kTHORN thornmekthorn bethbe thorn boTHORN s2thorn frac12bke thorn ethbe thorn boTHORNk sthorn kke

eth127THORN

where

bo frac14 k2bRe

eth128THORN

It is clear that under low damping conditions DdethsTHORN will produce two resonances as it is fourth order in sand similarly DethsTHORN will produce one antiresonance (trough) corresponding to the resonance of the testobject Note that in the frequency domain s frac14 jv and hence the frequency response function given by

Equation 125 is in fact

yevfrac14 kb

Rb

DethjvTHORNDdethjvTHORN eth129THORN

The magnitude of this frequency response function for a typical test system is sketched in Figure 110

Note that this curve is for the ldquoopen-looprdquo case where there is no feedback from the shaker controller

In practice the shaker controller will be able

to compensate for the resonances and anti-

resonances to some degree depending on its

effectiveness

The main advantages of electromagnetic

shakers are their high frequency range of

operation their high degree of operating flexi-

bility and the high level of accuracy of the

generated shaker motion Faithful reproduction

of complex excitations is possible because of the

advanced electronics and control systems used in

this type of shakers Electromagnetic shakers are

not suitable for heavy-duty applications (large test

objects) however High test-input accelerations

are possible at high frequencies when electromag-

netic shakers are used but their displacement and

velocity capabilities are limited to low or

intermediate values (see Table 11)

100

10

1 10 100Excitation Frequency (Hz)

Antiresonance

Resonance

Shak

erD

ispl

acem

entM

agni

tude

Resonance

1000

FIGURE 110 Frequency response curve of a typical

electromagnetic shaker with a test object

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1221 Transient Exciters

Other varieties of exciters are commonly used in

transient-type vibration testing In these tests

either an impulsive force or an initial excitation is

applied to the test object and the resulting

response is monitored The excitations and the

responses are ldquotransientrdquo in this case Hammer

test drop tests and pluck tests fall into this

category For example a hammer test may be

conducted by hitting the object with an instru-

mented hammer and then measuring the response

of the object The hammer has a force sensor at its

tip as sketched in Figure 111 A piezoelectric or

strain-gage type force sensor may be used More

sophisticated hammers have impedance heads in

place of force sensors An impedance head

measures force and acceleration simultaneously

The results of a hammer test will depend on many

factors for example the dynamics of the hammer

body how firmly the hammer is held during the

impact how quickly the impact is applied and

whether there are multiple impacts

13 Control System

The two primary functions of the shaker control system in vibration testing are (1) to guarantee that the

specified excitation is applied to the test object and (2) to ensure that the dynamic stability (motion

constraints) of the test setup is preserved An operational block diagram illustrating these control

functions is given in Figure 112 The reference input to the control system represents the desired

excitation force that should be applied to the test object In the absence of any control however the force

reaching the test object will be distorted primarily because of (1) dynamic interactions and

nonlinearities of the shaker the test table the mounting fixtures the auxiliary instruments and the test

object itself (2) noise and errors in the signal generator amplifiers filters and other equipment and (3)

external loads and disturbances acting on the test object and other components (for example external

restraints aerodynamic forces friction) To compensate for these distorting factors response

measurements (displacements velocities acceleration and so on) are made at various locations in the

test setup and are used to control the system dynamics In particular the responses of the shaker the test

table and the test object are measured These responses are used to compare the actual excitation felt by

FIGURE 111 An instrumented hammer used in bump

tests or hammer tests

ExcitationInput

(Reference)

Feedback Paths

DriveSignal

ShakerResponse

TestTable

TestObject

Test ObjectResponse

Test TableResponseExciter

(Shaker)(Ram)

Controllerand

Amplifier

FIGURE 112 Operational block diagram illustrating a general shaker control system

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the test object at the shaker interface with the desired (specified) input The drive signal to the shaker is

modified depending on the error that is present

Two types of control are commonly employed in shaker apparatus simple manual control and

complex automatic control Manual control normally consists of simple open-loop trial-and-error

methods of manual adjustments (or calibration) of the control equipment to obtain a desired dynamic

response The actual response is usually monitored (on an oscilloscope or frequency analyzer screen for

example) during manual-control operations The pretest adjustments in manual control can be very

time-consuming as a result the test object might be subjected to overtesting which could produce

cumulative damage is undesirable and could defeat the test purpose Furthermore the calibration

procedure for the experimental setup must be repeated for each new test object

The disadvantages ofmanual control suggest that automatic control is desirable in complex test schemes

in which high accuracy of testing is desired The first step of automatic control involves automatic

measurement of the system response using control sensors and transducers The measurement is then fed

back into the control system which instantaneously determines the best drive signal to actuate the shaker

in order to get the desired excitation This may be done by either analog or digital methods

Primitive control systems require an accurate mathematical description of the test object This

dependency of the control system on the knowledge of test-object dynamics is clearly undesirable

Performance of a good control system should not be considerably affected by the dynamic interactions

and nonlinearities of the test object or by the nature of the excitation Proper selection of feedback signals

and control-system components can reduce such effects and will make the system robust

In the response-spectrum method of vibration testing it is customary to use displacement control at

low frequencies velocity control at intermediate frequency and acceleration control at high frequencies

This necessitates feedback of displacement velocity and acceleration responses Generally however the

most important feedback is the velocity feedback In sine-sweep tests the shaker velocity must change

steadily over the frequency band of interest In particular the velocity control must be precise near the

resonances of the test object Velocity (speed) feedback has a stabilizing effect on the dynamics which is

desirable This effect is particularly useful in ensuring stability in motion when testing is done near

resonances of lightly damped test objects On the contrary displacement (position) feedback can have a

destabilizing effect on some systems particularly when high feedback gains are used

The controller usually consists of various instruments equipment and computation hardware and

software Often the functions of the data-acquisition and processing system overlap with those of the

controller to some extent As an example consider the digital-controller of vibration testing apparatus

First the responses are measured through sensors (and transducers) filtered and amplified

(conditioned) These data channels may be passed through a multiplexer whose purpose is to select

one data channel at a time for processing Most modern data acquisition hardware does not need a

separate multiplexer to handle multiple signals The analog data are converted into digital data using

analog-to-digital converters (ADCs) The resulting sampled data are stored on a disk or as a block data in

the computer memory The reference input signal (typically a signal recorded on an FM tape) is also

sampled (if it is not already in the digital form) using an ADC and fed into the computer Digital

processing is done on the reference signal and the response data with the objective of computing the

command signal to drive the shaker The digital command signal is converted into an analog signal using

a digital-to-analog converter (DAC) and amplified (conditioned) before it is used to drive the exciter

The nature of the control components depends to a large extent on the nature and objectives of the

particular test to be conducted Some of the basic components in a shaker controller are described in

the following subsections

131 Components of a Shaker Controller

1311 Compressor

A compressor circuit is incorporated in automatic excitation control devices to control the excitation-

input level automatically The level of control depends on the feedback signal from a control sensor and

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the specified (reference) excitation signal Usually the compressor circuit is included in the excitation-

signal generator (for example in a sine generator) The control by this means may be done on the basis of

a single-frequency component (eg the fundamental frequency)

1312 Equalizer (Spectrum Shaper)

Random-signal equalizers are used to shape the spectrum of a random signal in a desired manner In

essence and equalizer consists of a bank of narrow-band filters (for example 80 filters) in parallel over

the operating frequency range By passing the signal through each filter the spectral density (or the mean

square value) of the signal in that narrow frequency band (for example each one-third-octave band) is

determined This is compared with the desired spectral level and automatic adjustment is made in that

filter in case there is an error In some systems response-spectrum analysis is made in place of power

spectral density analysis In that case the equalizer consists of a bank of simple oscillators whose

resonant frequencies are distributed over the operating frequency range of the equalizer The feedback

signal is passed through each oscillator and the peak value of its output is determined This value is

compared with the desired response spectrum value at that frequency If there is an error automatic gain

adjustment is made in the appropriate excitation signal components

Random-noise equalizers are used in conjunction with random signal generators They receive

feedback signals from the control sensors In some digital control systems there are algorithms (software)

that are used to iteratively converge the spectrum of the excitation signal felt by the test object into the

desired spectrum

1313 Tracking Filter

Many vibration tests are based on single-frequency excitations In such cases the control functions

should be performed on the basis of the amplitudes of the fundamental-frequency component of the

signal A tracking filter is simply a frequency-tuned band-pass filter It automatically tunes the center

frequency of its very narrow-band-pass filter to the frequency of a carrier signal Then when a noisy

signal is passed through the tuned filter the output of the filter will be the required fundamental

frequency component in the signal Tracking filters also are useful in obtaining amplitudendashfrequency

plots using an XndashY plotter In such cases the frequency value comes from the signal generator (sweep

oscillator) which produces the carrier signal to the tracking filter The tracking filter then determines the

corresponding amplitude of a signal that is fed into it Most tracking filters have dual channels so that two

signals can be handled (tracked) simultaneously

1314 Excitation Controller (Amplitude Servo-Monitor)

An excitation controller is typically an integral part of the signal generator It can be set so that automatic

sweep between two frequency limits can be performed at a selected sweep rate (linear or logarithmic)

More advanced excitation controllers have the capability of an automatic switch-over between constant-

displacement constant-velocity and constant-acceleration excitation-input control at specified

frequencies over the sweep frequency interval Consequently integrator circuits should be present

within the excitation controller unit to determine velocities and displacements from acceleration signals

Sometimes integration is performed by a separate unit called a vibration meter This unit also offers

the operator the capability of selecting the desired level of each signal (acceleration velocity or

displacement) There is an automatic cut-off level for large displacement values that could result from

noise in acceleration signals A compressor is also a subcomponent of the excitation controller The

complete unit is sometimes known as an amplitude servo-monitor

132 Signal-Generating Equipment

Shakers are force-generating devices that are operated using drive (excitation) signals generated from a

source The excitation-signal source is known as the signal generator Three major types of signal

generators are used in vibration testing applications (1) oscillators (2) random-signal generators and

(3) storage devices In some units oscillators and random-signal generators are combined We shall

Vibration Instrumentation 1-17

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copy 2007 by Taylor amp Francis Group LLC

discuss these two generators separately however because of their difference in function It also should be

noted that almost any digital signal (deterministic or random) can be generated by a digital computer

using a suitable computer program the signal eventually can be passed through a DAC to obtain

the corresponding analog signal These lsquodigitalrsquo signal generators along with analog sources such as

magnetic tape players (FM) are classified into the category of storage devices

The dynamic range of equipment is the ratio of the maximum and minimum output levels (expressed

in decibels) at which it is capable of operating without significant error This is an important specification

for many types of equipment particularly for signal-generating devices The output level of the signal

generator should be set to a value within its dynamic range

1321 Oscillators

Oscillators are essentially single-frequency generators Typically sine signals are generated but other

waveforms (such as rectangular and triangular pulses) are also available in most oscillators Normally

an oscillator has two modes of operation (1) sweeping up and down between two frequency limits and

(2) dwelling at a specified frequency In the sweep operation the sweep rate should be specified This can

be done either on a linear scale (Hzmin) or on a logarithmic scale (octavesmin) In the dwell operation

the frequency points (or intervals) should be specified In either case a desired signal level can be chosen

using the gain-control knob An oscillator that is operated exclusively in the sweep mode is called a sweep

oscillator

The early generation of oscillators employed variable inductor-capacitor types of electronic circuits to

generate signals oscillating at a desired frequency The oscillator is tuned to the required frequency by

varying the capacitance or inductance parameters A DC voltage is applied to energize the capacitor

and to obtain the desired oscillating voltage signal which subsequently is amplified and conditioned

Modern oscillators use operational amplifier circuits along with resistor capacitor and semiconductor

(SC) elements Also common are crystal (quartz) parallel-resonance oscillators used to generate voltage

signals accurately at a fixed frequency The circuit is activated using a DC-voltage source Other

frequencies of interest are obtained by passing this high-frequency signal through a frequency converter

The signal is then conditioned (amplified and filtered) Required shaping (for example rectangular

pulse) is obtained using a shape circuit Finally the required signal level is obtained by passing the

resulting signal through a variable-gain amplifier A block diagram of an oscillator illustrating various

stages in the generation of a periodic signal is given in Figure 113

A typical oscillator offers a choice of several (typically six) linear and logarithmic frequency ranges and

a sizable level of control capability (for example 80 dB) Upper and lower frequency limits in a sweep can

be preset on the front panel to any of the available frequency ranges Sweep-rate settings are continuously

DC Voltage

Oscillator

FrequencySpecification

FrequencyConverter

FilterAmplifier

ShaperPeriodicSignal

FrequencyCounter

Fixed-FrequencySignal

Variable-GainOutput

Amplifier

SignalSpecification

LevelSpecification

FIGURE 113 Block diagram of an oscillator-type signal generator

Vibration Monitoring Testing and Instrumentation1-18

53191mdash522007mdash1202mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

  • 53191fm
    • Vibration Monitoring Testing and Instrumentation
      • Preface
      • Acknowledgments
      • Editor-in-Chief
      • Contributors
      • Contents
      • Related Titles
          • 53191ch1
            • Table of Contents
            • Chapter 1 Vibration Instrumentation
              • Summary
              • 11 Introduction
              • 12 Vibration Exciters
                • 121 Shaker Selection
                  • 1211 Force Rating
                  • 1212 Power Rating
                  • 1213 Stroke Rating
                  • 1214 Hydraulic Shakers
                  • 1215 Inertial Shakers
                  • 1216 Electromagnetic Shakers
                    • 122 Dynamics of Electromagnetic Shakers
                      • 1221 Transient Exciters
                          • 13 Control System
                            • 131 Components of a Shaker Controller
                              • 1311 Compressor
                              • 1312 Equalizer (Spectrum Shaper)
                              • 1313 Tracking Filter
                              • 1314 Excitation Controller (Amplitude Servo-Monitor)
                                • 132 Signal-Generating Equipment
                                  • 1321 Oscillators
                                  • 1322 Random Signal Generators
                                  • 1323 Tape Players
                                  • 1324 Data Processing
                                      • 14 Performance Specification
                                        • 141 Parameters for Performance Specification
                                          • 1411 Time-Domain Specifications
                                          • 1412 Frequency-Domain Specifications
                                            • 142 Linearity
                                            • 143 Instrument Ratings
                                              • 1431 Rating Parameters
                                                • 144 Accuracy and Precision
                                                  • 15 Motion Sensors and Transducers
                                                    • 151 Potentiometer
                                                      • 1511 Potentiometer Resolution
                                                      • 1512 Optical Potentiometer
                                                        • 152 Variable-Inductance Transducers
                                                          • 1521 Mutual-Induction Transducers
                                                          • 1522 Linear-Variable Differential Transformer
                                                          • 1523 Signal Conditioning
                                                            • 153 Mutual-Induction Proximity Sensor
                                                            • 154 Selfinduction Transducers
                                                            • 155 Permanent-Magnet Transducers
                                                            • 156 Alternating Current Permanent-Magnet Tachometer
                                                            • 157 Alternating Current Induction Tachometer
                                                            • 158 Eddy Current Transducers
                                                            • 159 Variable-Capacitance Transducers
                                                              • 1591 Capacitive Displacement Sensors
                                                              • 1592 Capacitive Angular Velocity Sensor
                                                              • 1593 Capacitance Bridge Circuit
                                                                • 1510 Piezoelectric Transducers
                                                                  • 15101 Sensitivity
                                                                  • 15102 Piezoelectric Accelerometer
                                                                  • 15103 Charge Amplifier
                                                                      • 16 Torque Force and Other Sensors
                                                                        • 161 Strain Gage Sensors
                                                                          • 1611 Equations for Strain Gage Measurements
                                                                          • 1612 Bridge Sensitivity
                                                                          • 1613 The Bridge Constant
                                                                          • 1614 The Calibration Constant
                                                                          • 1615 Data Acquisition
                                                                          • 1616 Accuracy Considerations
                                                                          • 1617 Semiconductor Strain Gages
                                                                          • 1618 Force and Torque Sensors
                                                                          • 1619 Strain Gage Torque Sensors
                                                                          • 16110 Deflection Torque Sensors
                                                                          • 16111 Variable-Reluctance Torque Sensor
                                                                          • 16112 Reaction Torque Sensors
                                                                            • 162 Miscellaneous Sensors
                                                                              • 1621 Stroboscope
                                                                              • 1622 Fiber Optic Sensors and Lasers
                                                                              • 1623 Fiber-Optic Gyroscope
                                                                              • 1624 Laser Doppler Interferometer
                                                                              • 1625 Ultrasonic Sensors
                                                                              • 1626 Gyroscopic Sensors
                                                                                  • References
                                                                                  • Appendix 1A Virtual Instrumentation for Data Acquisition Analysis and Presentation
                                                                                    • Summary
                                                                                    • List of Abbreviations
                                                                                    • 1A1 Dynamic Signals
                                                                                      • 1A11 Acquiring and Simulating Dynamic Signals
                                                                                        • 1A111 Aliasing
                                                                                        • 1A112 Time Continuity
                                                                                            • 1A2 Measurement Configuration Considerations
                                                                                              • 1A21 Input Signal Considerations
                                                                                                • 1A211 Input Pseudodifferential and Differential Configuration
                                                                                                • 1A212 Gain
                                                                                                • 1A213 Input Coupling
                                                                                                • 1A214 Integrated Electronic Piezoelectric Excitation
                                                                                                • 1A215 Nyquist Frequency and Bandwidth
                                                                                                • 1A216 Analog-to-Digital Conversion
                                                                                                • 1A217 Antialias Filters
                                                                                                • 1A218 Input Filter Delay
                                                                                                • 1A219 Overload Detection
                                                                                                  • 1A22 Output Signal Considerations
                                                                                                    • 1A221 Output Pseudodifferential and Differential Configuration
                                                                                                    • 1A222 Attenuation
                                                                                                    • 1A223 Digital-to-Analog Conversion
                                                                                                    • 1A224 Anti-imaging and Interpolation Filters
                                                                                                    • 1A225 Output Filter Delay
                                                                                                        • 1A3 Scaling and Calibration
                                                                                                          • 1A31 Scaling to Engineering Units
                                                                                                          • 1A32 Performing System Calibration
                                                                                                            • 1A321 Propagation Delay Calibration
                                                                                                                • 1A4 Limit Testing Analysis
                                                                                                                  • 1A41 Limit Testing Overview
                                                                                                                  • 1A42 Using the SVT Limit Testing VI
                                                                                                                    • 1A5 Integration
                                                                                                                      • 1A51 Introduction to Integration
                                                                                                                      • 1A52 Implementing Integration
                                                                                                                        • 1A521 Challenges when Integrating Vibration Data
                                                                                                                          • 1A53 Time-Domain Integration
                                                                                                                            • 1A531 Single-Shot Acquisition and Integration
                                                                                                                            • 1A532 Continuous Acquisition and Integration
                                                                                                                              • 1A54 Frequency-Domain Integration
                                                                                                                                • 1A6 Vibration-Level Measurements
                                                                                                                                  • 1A61 Measuring the Root Mean Square Level
                                                                                                                                    • 1A611 Single-Shot Buffered Acquisition
                                                                                                                                    • 1A612 Continuous Signal Acquisition
                                                                                                                                      • 1A62 Performing a Running RMS Level Measurement
                                                                                                                                      • 1A63 Computing the Peak Level
                                                                                                                                      • 1A64 Computing the Crest Factor
                                                                                                                                        • 1A7 Frequency Analysis
                                                                                                                                          • 1A71 FFT Fundamentals
                                                                                                                                            • 1A711 Number of Samples
                                                                                                                                            • 1A712 Frequency Resolution
                                                                                                                                            • 1A713 Maximum Resolvable Frequency
                                                                                                                                            • 1A714 Minimum Resolvable Frequency
                                                                                                                                            • 1A715 Number of Spectral Lines
                                                                                                                                            • 1A716 Relationship between Time-Domain and Frequency-Domain Specifications and Parameters
                                                                                                                                              • 1A72 Increasing Frequency Resolution
                                                                                                                                                • 1A721 Zoom FFT Analysis
                                                                                                                                                • 1A722 Frequency Resolution of the Zoom FFT VIs
                                                                                                                                                • 1A723 Zoom Measurement
                                                                                                                                                • 1A724 Zoom Settings
                                                                                                                                                • 1A725 Subset Analysis
                                                                                                                                                    • 1A8 Transient Analysis
                                                                                                                                                      • 1A81 Transient Analysis with the Sound and Vibration Toolkit
                                                                                                                                                      • 1A82 Performing an STFT vs Time
                                                                                                                                                        • 1A821 Selecting the FFT Block Size
                                                                                                                                                        • 1A822 Overlapping
                                                                                                                                                        • 1A823 Using the SVT STFT vs Time VI
                                                                                                                                                          • 1A83 Performing an STFT vs Rotational Speed
                                                                                                                                                            • 1A831 Converting the Pulse Train to Rotational Speed
                                                                                                                                                            • 1A832 STFT vs RPM
                                                                                                                                                              • 1A84 Measuring a Shock Response Spectrum
                                                                                                                                                                • 1A9 Waterfall Display
                                                                                                                                                                  • 1A91 Using the Display VIs
                                                                                                                                                                    • 1A911 Initializing the Display
                                                                                                                                                                    • 1A912 Sending Data to the Display
                                                                                                                                                                    • 1A913 Waterfall Display for Frequency Analysis
                                                                                                                                                                    • 1A914 Waterfall Display for Transient Analysis
                                                                                                                                                                    • 1A915 Waterfall Display for Octave Spectra
                                                                                                                                                                        • 1A10 Swept-Sine Measurements
                                                                                                                                                                          • 1A101 Swept-Sine Overview
                                                                                                                                                                          • 1A102 Choosing Swept-Sine vs FFT Measurements
                                                                                                                                                                          • 1A103 Taking a Swept-Sine Measurement
                                                                                                                                                                          • 1A104 Swept-Sine Measurement Example
                                                                                                                                                                              • Bibliography
                                                                                                                                                                              • Related Titles
                                                                                                                                                                                  • 53191ch2
                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                    • Chapter 2 Signal Conditioning and Modification
                                                                                                                                                                                      • Summary
                                                                                                                                                                                      • 21 Introduction
                                                                                                                                                                                      • 22 Amplifiers
                                                                                                                                                                                        • 221 Operational Amplifier
                                                                                                                                                                                        • 222 Use of Feedback in Opamp
                                                                                                                                                                                        • 223 Voltage Current and Power Amplifiers
                                                                                                                                                                                          • 2231 Charge Amplifiers
                                                                                                                                                                                            • 224 Instrumentation Amplifiers
                                                                                                                                                                                              • 2241 Differential Amplifier
                                                                                                                                                                                              • 2242 Common Mode
                                                                                                                                                                                                • 225 Amplifier Performance Ratings
                                                                                                                                                                                                  • 2251 Common-Mode Rejection Ratio
                                                                                                                                                                                                    • 226 Component Interconnection
                                                                                                                                                                                                      • 2261 Impedance Characteristics
                                                                                                                                                                                                      • 2262 Cascade Connection of Devices
                                                                                                                                                                                                      • 2263 AC-Coupled Ampliers
                                                                                                                                                                                                          • 23 Analog Filters
                                                                                                                                                                                                            • 231 Passive Filters and Active Filters
                                                                                                                                                                                                              • 2311 Number of Poles
                                                                                                                                                                                                                • 232 Low-Pass Filters
                                                                                                                                                                                                                  • 2321 Low-Pass Butterworth Filter
                                                                                                                                                                                                                    • 233 High-Pass Filters
                                                                                                                                                                                                                    • 234 Band-Pass Filters
                                                                                                                                                                                                                      • 2341 Resonance-Type Band-Pass Filters
                                                                                                                                                                                                                        • 235 Band-Reject Filters
                                                                                                                                                                                                                          • 24 Modulators and Demodulators
                                                                                                                                                                                                                            • 241 Amplitude Modulation
                                                                                                                                                                                                                              • 2411 Modulation Theorem
                                                                                                                                                                                                                              • 2412 Side Frequencies and Side Bands
                                                                                                                                                                                                                                • 242 Application of Amplitude Modulation
                                                                                                                                                                                                                                  • 2421 Fault Detection and Diagnosis
                                                                                                                                                                                                                                    • 243 Demodulation
                                                                                                                                                                                                                                      • 25 Analog ndashDigital Conversion
                                                                                                                                                                                                                                        • 251 Digital-to-Analog Conversion
                                                                                                                                                                                                                                          • 2511 DAC Error Sources
                                                                                                                                                                                                                                            • 252 Analog-to-Digital Conversion
                                                                                                                                                                                                                                            • 253 Analog-to-Digital Converter Performance Characteristics
                                                                                                                                                                                                                                              • 2531 Resolution and Quantization Error
                                                                                                                                                                                                                                              • 2532 Monotonicity Nonlinearity and Offset Error
                                                                                                                                                                                                                                              • 2533 Analog-to-Digital Converter Conversion Rate
                                                                                                                                                                                                                                                • 254 Sample-and-Hold Circuitry
                                                                                                                                                                                                                                                • 255 Digital Filters
                                                                                                                                                                                                                                                  • 2551 Software Implementation and Hardware Implementation
                                                                                                                                                                                                                                                      • 26 Bridge Circuits
                                                                                                                                                                                                                                                        • 261 Wheatstone Bridge
                                                                                                                                                                                                                                                        • 262 Constant-Current Bridge
                                                                                                                                                                                                                                                        • 263 Bridge Amplifiers
                                                                                                                                                                                                                                                          • 2631 Half-Bridge Circuits
                                                                                                                                                                                                                                                            • 264 Impedance Bridges
                                                                                                                                                                                                                                                              • 2641 Owen Bridge
                                                                                                                                                                                                                                                              • 2642 Wien-Bridge Oscillator
                                                                                                                                                                                                                                                                  • 27 Linearizing Devices
                                                                                                                                                                                                                                                                    • 271 Linearization by Software
                                                                                                                                                                                                                                                                    • 272 Linearization by Hardware Logic
                                                                                                                                                                                                                                                                    • 273 Analog Linearizing Circuitry
                                                                                                                                                                                                                                                                    • 274 Offsetting Circuitry
                                                                                                                                                                                                                                                                    • 275 Proportional-Output Circuitry
                                                                                                                                                                                                                                                                      • 2751 Curve-Shaping Circuitry
                                                                                                                                                                                                                                                                          • 28 Miscellaneous Signal Modification Circuitry
                                                                                                                                                                                                                                                                            • 281 Phase Shifters
                                                                                                                                                                                                                                                                            • 282 Voltage-to-Frequency Converter
                                                                                                                                                                                                                                                                            • 283 Frequency-to-Voltage Converter
                                                                                                                                                                                                                                                                            • 284 Voltage-to-Current Converters
                                                                                                                                                                                                                                                                            • 285 Peak-Hold Circuits
                                                                                                                                                                                                                                                                              • 29 Signal Analyzers and Display Devices
                                                                                                                                                                                                                                                                                • 291 Signal Analyzers
                                                                                                                                                                                                                                                                                • 292 Oscilloscopes
                                                                                                                                                                                                                                                                                  • 2921 Triggering
                                                                                                                                                                                                                                                                                  • 2922 Lissajous Patterns
                                                                                                                                                                                                                                                                                  • 2923 Digital Oscilloscopes
                                                                                                                                                                                                                                                                                      • Bibliography
                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                          • 53191ch3
                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                            • Chapter 3 Vibration Testing
                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                              • 31 Introduction
                                                                                                                                                                                                                                                                                              • 32 Representation of a Vibration Environment
                                                                                                                                                                                                                                                                                                • 321 Test Signals
                                                                                                                                                                                                                                                                                                  • 3211 Stochastic vs Deterministic Signals
                                                                                                                                                                                                                                                                                                    • 322 Deterministic Signal Representation
                                                                                                                                                                                                                                                                                                      • 3221 Single-Frequency Signals
                                                                                                                                                                                                                                                                                                      • 3222 Sine Sweep
                                                                                                                                                                                                                                                                                                      • 3223 Sine Dwell
                                                                                                                                                                                                                                                                                                      • 3224 Decaying Sine
                                                                                                                                                                                                                                                                                                      • 3225 Sine Beat
                                                                                                                                                                                                                                                                                                      • 3226 Sine Beat with Pauses
                                                                                                                                                                                                                                                                                                      • 3227 Multifrequency Signals
                                                                                                                                                                                                                                                                                                      • 3228 Actual Excitation Records
                                                                                                                                                                                                                                                                                                      • 3229 Simulated Excitation Signals
                                                                                                                                                                                                                                                                                                        • 323 Stochastic Signal Representation
                                                                                                                                                                                                                                                                                                          • 3231 Ergodic Random Signals
                                                                                                                                                                                                                                                                                                          • 3232 Stationary Random Signals
                                                                                                                                                                                                                                                                                                          • 3233 Independent and Uncorrelated Signals
                                                                                                                                                                                                                                                                                                          • 3234 Transmission of Random Excitations
                                                                                                                                                                                                                                                                                                            • 324 Frequency-Domain Representations
                                                                                                                                                                                                                                                                                                              • 3241 Fourier Spectrum Method
                                                                                                                                                                                                                                                                                                              • 3242 Power Spectral Density Method
                                                                                                                                                                                                                                                                                                                • 325 Response Spectrum
                                                                                                                                                                                                                                                                                                                  • 3251 Displacement Velocity and Acceleration Spectra
                                                                                                                                                                                                                                                                                                                  • 3252 Response-Spectra Plotting Paper
                                                                                                                                                                                                                                                                                                                  • 3253 Zero-Period Acceleration
                                                                                                                                                                                                                                                                                                                  • 3254 Uses of Response Spectra
                                                                                                                                                                                                                                                                                                                    • 326 Comparison of Various Representations
                                                                                                                                                                                                                                                                                                                      • 33 Pretest Procedures
                                                                                                                                                                                                                                                                                                                        • 331 Purpose of Testing
                                                                                                                                                                                                                                                                                                                        • 332 Service Functions
                                                                                                                                                                                                                                                                                                                          • 3321 Active Equipment
                                                                                                                                                                                                                                                                                                                          • 3322 Passive Equipment
                                                                                                                                                                                                                                                                                                                          • 3323 Functional Testing
                                                                                                                                                                                                                                                                                                                            • 333 Information Acquisition
                                                                                                                                                                                                                                                                                                                              • 3331 Interface Details
                                                                                                                                                                                                                                                                                                                              • 3332 Effect of Neglecting Interface Dynamics
                                                                                                                                                                                                                                                                                                                              • 3333 Effects of Damping
                                                                                                                                                                                                                                                                                                                              • 3334 Effects of Inertia
                                                                                                                                                                                                                                                                                                                              • 3335 Effect of Natural Frequency
                                                                                                                                                                                                                                                                                                                              • 3336 Effect of Excitation Frequency
                                                                                                                                                                                                                                                                                                                              • 3337 Other Effects of Interface
                                                                                                                                                                                                                                                                                                                                • 334 Test-Program Planning
                                                                                                                                                                                                                                                                                                                                  • 3341 Testing of Cabinet-Mounted Equipment
                                                                                                                                                                                                                                                                                                                                    • 335 Pretest Inspection
                                                                                                                                                                                                                                                                                                                                      • 34 Testing Procedures
                                                                                                                                                                                                                                                                                                                                        • 341 Resonance Search
                                                                                                                                                                                                                                                                                                                                        • 342 Methods of Determining Frequency-Response Functions
                                                                                                                                                                                                                                                                                                                                          • 3421 Fourier Transform Method
                                                                                                                                                                                                                                                                                                                                          • 3422 Spectral Density Method
                                                                                                                                                                                                                                                                                                                                          • 3423 Harmonic Excitation Method
                                                                                                                                                                                                                                                                                                                                            • 343 Resonance-Search Test Methods
                                                                                                                                                                                                                                                                                                                                              • 3431 Hammer (Bump) Test and Drop Test
                                                                                                                                                                                                                                                                                                                                              • 3432 Pluck Test
                                                                                                                                                                                                                                                                                                                                              • 3433 Shaker Tests
                                                                                                                                                                                                                                                                                                                                                • 344 Mechanical Aging
                                                                                                                                                                                                                                                                                                                                                  • 3441 Equivalence for Mechanical Aging
                                                                                                                                                                                                                                                                                                                                                  • 3442 Excitation-Intensity Equivalence
                                                                                                                                                                                                                                                                                                                                                  • 3443 Dynamic-Excitation Equivalence
                                                                                                                                                                                                                                                                                                                                                  • 3444 Cumulative Damage Theory
                                                                                                                                                                                                                                                                                                                                                    • 345 Test-Response Spectrum Generation
                                                                                                                                                                                                                                                                                                                                                    • 346 Instrument Calibration
                                                                                                                                                                                                                                                                                                                                                    • 347 Test-Object Mounting
                                                                                                                                                                                                                                                                                                                                                    • 348 Test-Input Considerations
                                                                                                                                                                                                                                                                                                                                                      • 3481 Test Nomenclature
                                                                                                                                                                                                                                                                                                                                                      • 3482 Testing with Uncorrelated Excitations
                                                                                                                                                                                                                                                                                                                                                      • 3483 Symmetrical Rectilinear Testing
                                                                                                                                                                                                                                                                                                                                                      • 3484 Geometry vs Dynamics
                                                                                                                                                                                                                                                                                                                                                      • 3485 Some Limitations
                                                                                                                                                                                                                                                                                                                                                      • 3486 Testing Black Boxes
                                                                                                                                                                                                                                                                                                                                                      • 3487 Phasing of Excitations
                                                                                                                                                                                                                                                                                                                                                      • 3488 Testing a Gray or White Box
                                                                                                                                                                                                                                                                                                                                                      • 3489 Overtesting in Multitest Sequences
                                                                                                                                                                                                                                                                                                                                                          • 35 Some Practical Information
                                                                                                                                                                                                                                                                                                                                                            • 351 Random Vibration Test Example
                                                                                                                                                                                                                                                                                                                                                            • 352 Vibration Shakers and Control Systems
                                                                                                                                                                                                                                                                                                                                                              • Bibliography
                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                  • 53191ch4
                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                    • Chapter 4 Experimental Modal Analysis
                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                      • 41 Introduction
                                                                                                                                                                                                                                                                                                                                                                      • 42 Frequency-Domain Formulation
                                                                                                                                                                                                                                                                                                                                                                        • 421 Transfer-Function Matrix
                                                                                                                                                                                                                                                                                                                                                                        • 422 Principle of Reciprocity
                                                                                                                                                                                                                                                                                                                                                                          • 43 Experimental Model Development
                                                                                                                                                                                                                                                                                                                                                                            • 431 Extraction of the Time-Domain Model
                                                                                                                                                                                                                                                                                                                                                                              • 44 Curve Fitting of Transfer Functions
                                                                                                                                                                                                                                                                                                                                                                                • 441 Problem Identification
                                                                                                                                                                                                                                                                                                                                                                                • 442 Single- and Multi-Degree-of-Freedom Techniques
                                                                                                                                                                                                                                                                                                                                                                                • 443 Single-Degree-of-Freedom Parameter Extraction in the Frequency Domain
                                                                                                                                                                                                                                                                                                                                                                                  • 4431 Circle-Fit Method
                                                                                                                                                                                                                                                                                                                                                                                    • Case of Viscous Damping
                                                                                                                                                                                                                                                                                                                                                                                    • Case of Hysteretic Damping
                                                                                                                                                                                                                                                                                                                                                                                      • 4432 Peak-Picking Method
                                                                                                                                                                                                                                                                                                                                                                                        • 444 Multi-Degree of Freedom Curve Fitting
                                                                                                                                                                                                                                                                                                                                                                                          • 4441 Formulation of the Method
                                                                                                                                                                                                                                                                                                                                                                                            • 445 A Comment on Static Modes and Rigid-Body Modes
                                                                                                                                                                                                                                                                                                                                                                                            • 446 Residue Extraction
                                                                                                                                                                                                                                                                                                                                                                                              • 45 Laboratory Experiments
                                                                                                                                                                                                                                                                                                                                                                                                • 451 Lumped-Parameter System
                                                                                                                                                                                                                                                                                                                                                                                                  • 4511 Frequency-Domain Test
                                                                                                                                                                                                                                                                                                                                                                                                  • 4512 Time-Domain Tests
                                                                                                                                                                                                                                                                                                                                                                                                    • 452 Distributed-Parameter System
                                                                                                                                                                                                                                                                                                                                                                                                      • 46 Commercial EMA Systems
                                                                                                                                                                                                                                                                                                                                                                                                        • 461 System Configuration
                                                                                                                                                                                                                                                                                                                                                                                                          • 4611 FFT Analysis Options
                                                                                                                                                                                                                                                                                                                                                                                                          • 4612 Modal Analysis Components
                                                                                                                                                                                                                                                                                                                                                                                                              • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                  • 53191ch5
                                                                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                    • Chapter 5 Mechanical Shock
                                                                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                      • 51 Definitions
                                                                                                                                                                                                                                                                                                                                                                                                                        • 511 Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 512 Simple (or Perfect) Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 513 Half-Sine Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 514 Versed-Sine (or Haversine) Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 515 Terminal Peak Sawtooth Shock or Final Peak Sawtooth Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 516 Rectangular Shock
                                                                                                                                                                                                                                                                                                                                                                                                                          • 5161 Trapezoidal Shock
                                                                                                                                                                                                                                                                                                                                                                                                                              • 52 Description in the Time Domain
                                                                                                                                                                                                                                                                                                                                                                                                                              • 53 Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                • 531 Need
                                                                                                                                                                                                                                                                                                                                                                                                                                • 532 Shock Response Spectrum Definition
                                                                                                                                                                                                                                                                                                                                                                                                                                • 533 Response of a Linear One-Degree-of-Freedom System
                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5331 Shock Defined by a Force
                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5332 Shock Defined by an Acceleration
                                                                                                                                                                                                                                                                                                                                                                                                                                    • 534 Definitions
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5341 Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5342 Absolute Acceleration Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5343 Relative Displacement Shock Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5344 Primary Positive Shock Response Spectrum or Initial Positive Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5345 Primary (or Initial) Negative Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5346 Secondary (or Residual) Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5347 Positive (or Maximum Positive) Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5348 Negative (or Maximum Negative) Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5349 Maximax Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53410 Choice of Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                        • 535 Standardized Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5351 Definition
                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5352 Standardized Shock Response Spectra of Simple Shocks
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53521 Half-Sine Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53522 Versed Sine Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53523 Terminal Peak Sawtooth Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53524 Rectangular Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53525 Trapezoidal Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 536 Choice of Damping
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 537 Shock Response Spectra Domains
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 538 Algorithms for Calculation of the Shock Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 539 Choice of the Digitization Frequency of the Signal
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5310 Use of Shock Response Spectra for the Study of Systems with Several Degrees of Freedom
                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 54 Pyroshocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 55 Use of Shock Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 551 Severity Comparison of Several Shocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 552 Test Specification Development from Real Environment Data
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5521 Synthesis of Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5522 Nature of the Specification
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5523 Choice of Shape
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5524 Amplitude
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5525 Duration
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5526 Difficulties
                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 56 Standards
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 561 Types of Standards
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 562 Installation Conditions of Test Item
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 563 Uncertainty Factor
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 564 Bump Test
                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 57 Damage Boundary Curve
                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 571 Definition
                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 572 Analysis of Test Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 58 Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 581 Main Types
                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 582 Impact Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5821 Universal Shock-Test Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 58211 Impact Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 58212 Impulse Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 583 Shock Simulators (Programmers)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5831 Half-Sine Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58311 Shock Duration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58312 Impact Velocity
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58313 Maximum Deformation of the Shock Simulator (Programmer)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58314 Shock Amplitude
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58315 Characteristics of the Target
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5832 Terminal Peak Sawtooth Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5833 Rectangular Pulse ndash Trapezoidal Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5834 Universal Shock Simulator (Programmer)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 58341 Generating a Half-Sine Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 58342 Generating a Terminal Peak Sawtooth Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 58343 Trapezoidal Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 584 Limitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5841 Limitations of the Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5842 Limitations of Shock Simulators
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 585 Pneumatic Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 586 High Impact Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5861 Lightweight High Impact Shock Machine
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5862 Medium Weight High Impact Shock Machine
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 587 Specific Test Facilities
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 59 Generation of Shock Using Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 591 Principle Behind the Generation of a Simple Shape Signal versus Time
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 592 Main Advantages
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 593 Pre- and Postshocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5931 Requirements
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5932 Solutions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 59321 Optimized Pre- and Postpulses
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5933 Incidence on the Shock Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 594 Limitations of Electrodynamic Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5941 Mechanical Limitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 59411 Abacuses
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5942 Electronic Limitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 595 The Use of Electrohydraulic Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 510 Control by a Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 5101 Principle
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 5102 Principal Shapes of Elementary Signals
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 51021 Decaying Sinusoid
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 51022 ZERD Function
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 51023 WAVSIN Waveform
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 5103 Comparison of WAVSIN SHOC Waveforms and Decaying Sinusoid
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 5104 Criticism of Control by a Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 511 Pyrotechnic Shock Simulation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5111 Simulation Using Pyrotechnic Facilities
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5112 Simulation Using Metal-to-Metal Impact
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5113 Simulation Using Electrodynamic Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5114 Simulation Using Conventional Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53191ch6
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Chapter 6 Machine Condition Monitoring and Fault Diagnostics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 61 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 62 Machinery Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 621 Causes of Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 622 Types of Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 623 Frequency of Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 63 Basic Maintenance Strategies
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 631 Run-to-Failure (Breakdown) Maintenance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 632 Scheduled (Preventative) Maintenance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 633 Condition-Based (Predictive Proactive Reliability Centered On-Condition) Maintenance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 64 Factors Which Influence Maintenance Strategy
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 65 Machine Condition Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 651 Periodic Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 652 Continuous Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 66 Transducer Selection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 661 Noncontact Displacement Transducers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 662 Velocity Transducers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 663 Acceleration Transducers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 67 Transducer Location
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 68 Recording and Analysis Instrumentation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 681 Vibration Meters
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 682 Data Collectors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 683 Frequency-Domain Analyzers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 684 Time-Domain Instruments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 685 Tracking Analyzers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 69 Display Formats and Analysis Tools
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 691 Time Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6911 Time-Waveform Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6912 Time-Waveform Indices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6913 Time-Synchronous Averaging
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6914 Negative Averaging
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6915 Orbits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6916 Probability Density Functions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6917 Probability Density Moments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 692 Frequency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6921 Band-Pass Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6922 Shock Pulse (Spike Energy)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6923 Enveloped Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6924 Signature Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6925 Cascades (Waterfall Plots)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6926 Masks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6927 Frequency-Domain Indices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 693 Modal Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 694 Quefrency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 610 Fault Detection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 6101 Standards
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61011 Standards Based on Machinery Type
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61012 Standards Based on Vibration Severity
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 6102 Acceptance Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 61021 Statistical Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 6103 Frequency-Domain Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61031 Limited Band Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61032 Constant Bandwidth Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61033 Constant Percentage Bandwidth Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 611 Fault Diagnostics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 6111 Forcing Functions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61111 Unbalance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61112 Misalignment
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61113 Mechanical Looseness
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61114 Soft Foot
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61115 Rubs
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61116 Resonances
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61117 Oil Whirl
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61118 Oil Whip
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61119 Structural Vibrations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 611110 Foundation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 6112 Specific Machine Components
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 61121 Damaged or Worn Rolling-Element Bearings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 61122 Damaged or Worn Gears
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 6113 Specific Machine Types
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61131 Pumps
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61132 Fans
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61133 Electric Motors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61134 Steam and Gas Turbines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61135 Compressors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61136 Reciprocating Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 6114 Advanced Fault Diagnostic Techniques
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 53191ch7
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • Chapter 7 Vibration-Based Tool Condition Monitoring Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 71 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 72 Mechanics of Turning
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 721 General Terms
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 722 Chatter Vibrations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 723 Tool Wear
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7231 Tool Failure Mechanisms
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7232 Tool Failure Modes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7233 Tool Wear Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7234 Tool Wear Stages
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 73 Vibration Signal Recording
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 731 Direct and Indirect Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 732 Sensor Requirements for Tool Wear Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 733 Force Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7331 Direct Measurement Dynamometers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7332 Indirect Force Sensors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7333 Piezoelectric Strain Sensors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7334 Resistance Strain Gauges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7335 Customized Force Sensors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 734 Acceleration Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 735 Acoustic Emission Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 736 Sensor Comparisons
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 74 Signal Processing for Sensor-Based Tool Condition Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 741 Feature Extraction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7411 Time Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7412 Frequency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7413 Statistical Processing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7414 TimendashFrequency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 742 Feature Selection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 75 Wear ModelDecision-Making for Sensor-Based Tool Condition Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 751 Trending Threshold
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 752 Neural Networks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7521 Unsupervised Networks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7522 Supervised Networks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 753 Fuzzy Logic
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 754 Other Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 76 Conclusion
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53191ch8
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Chapter 8 Fault Diagnosis of Helicopter Gearboxes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 81 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 82 Abnormality Scaling
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 83 The Structure-Based Connectionist Network
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 84 Sensor Location Selection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 841 Coverage Index
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 842 Overlap Index
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 843 Monitoring Effectiveness
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 85 A Case Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 851 Structural and Featural Influences
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 852 Evaluation of Influences
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 853 Fault Detection Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 854 Fault Diagnostic Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 8541 Faulty Subsystem Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 8542 Faulty Component Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 855 Sensor Location Evaluation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 856 Sensor Location Validation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 86 Conclusion
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 53191ch9
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Chapter 9 Vibration Suppression and Monitoring in Precision Motion Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 91 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 92 Mechanical Design to Minimize Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 921 Stability and Static Determinacy of Machine Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 922 Two-Dimensional Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 923 Three-Dimensional Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 93 Adaptive Notch Filter
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 931 Fast Fourier Transform
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 932 Simulation and Experiments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 94 Real-Time Vibration Analyzer
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 941 Learning Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 942 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 943 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 944 Experiments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 9441 Input Variables mdash the Evaluation Criteria
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 94411 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 94412 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 9442 Evaluation Rules
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 94421 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 94422 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 9443 Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 94431 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 94432 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 95 Practical Insights and Case Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 96 Conclusions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 53191ch10
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Chapter 10 Vibration and Shock Problems of Civil Engineering Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 101 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 102 Earthquake-Induced Vibration of Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1021 Seismicity and Ground Motions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1022 Influence of Local Site Conditions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1023 Response of Structures to Ground Motions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1024 Dynamic Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10241 Equations of Motion for Linear Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10242 Equations of Motion for Linear Multiple-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1025 Earthquake Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10251 Elastic Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10252 Smoothed Design Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10253 Ductility-Modified Response Spectrum Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1026 Design Philosophy and the Code Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10261 Performance-Based Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1027 Analysis Options for Earthquake Effects
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10271 Dynamic Time History Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10272 Response Spectrum Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 102721 Response Spectrum Analysis of Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 102722 Response Spectrum Analysis of Multi-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10273 Equivalent Static Analysis (Force-Based Approach)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10274 Displacement-Based Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1028 SoilndashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1029 Active and Passive Control Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 10210 Worked Examples
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 103 Dynamic Effects of Wind Loading on Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1031 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1032 Wind Speed
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1033 Design Structures for Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10331 Types of Wind Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10332 Design Criteria
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10333 Static Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1034 Along and Across-Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10341 Along-Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10342 Across-Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1035 Wind Tunnel Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1036 Comfort Criteria Human Response to Building Motion
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1037 Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1038 Comparison with Earthquake Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 104 Vibrations Due to Fluid ndashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1041 Added Mass and Inertial Coupling
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1042 Wave-Induced Vibration of Structure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 105 Blast Loading and Blast Effects on Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1051 Explosions and Blast Phenomenon
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1052 Explosive Air-Blast Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10521 Blast Wave Scaling Laws
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10522 Prediction of Blast Pressure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1053 Gas Explosion Loading and Effect of Internal Explosions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1054 Structural Response to Blast Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10541 Elastic Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10542 Elasto-Plastic Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1055 Material Behaviors at High Strain Rate
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10551 Dynamic Properties of Concrete under High Strain Rates
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10552 Dynamic Properties of Reinforcing Steel under High Strain Rates
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1056 Failure Modes of Blast-Loaded Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10561 Global Structural Behavior
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10562 Localized Structural Behavior
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10563 PressurendashImpulse ( PndashI ) Diagrams
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1057 Blast WavendashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1058 Effect of Ground Shocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10581 Loads from Air-Induced Ground Shock
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10582 Loads from Direct Ground Shock
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1059 Technical Design Manuals for Blast-Resistant Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 10510 Computer Programs for Blast and Shock Effects
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 106 Impact Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1061 Structural Impact between Two Bodies mdash Hard Impact and Soft Impact
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1062 Example mdash Aircraft Impact
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 107 Floor Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1071 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1072 Types of Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10721 Walking
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10722 Rhythmic Activities
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10723 Mechanical Equipment
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10724 Analysis Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1073 Natural Frequency of Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10731 Computing the Natural Frequency
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10732 Computing Deflection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10733 Damping
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10734 Resonance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1074 Vibration Caused by Walking
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10741 Minimum Natural Frequency
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1075 Design for Rhythmic Excitation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10751 Harmonics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10752 Minimum Natural Frequency
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1076 Example mdash Vibration Analysis of a Reinforced Concrete Floor
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 53191ch11
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Chapter 11 Seismic Base Isolation and Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 111 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1111 From Ductility Design to Base Isolation and Control Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1112 The Importance of Reducing Seismic Input and Response
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 112 Seismic Base Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1121 Historical Development of Base Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1122 Basic Principle
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1123 Issues in Seismic Base Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11231 Performance Criteria
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11232 Type of Structure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11233 Site Characteristics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11234 Retrofit Issues
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11235 Design of Building Services
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11236 Expected Life of Isolator
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1124 Seismic Isolation Devices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11241 Laminated Rubber Bearings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11242 Lead Rubber Bearing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11243 Friction-Based Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11244 Other Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1125 Design of Isolation Devices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11251 High-Damping Rubber Bearing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112511 Stability against Buckling
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112512 Stability against Roll Out
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11252 Lead Rubber Bearings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112521 Design of Lead Plug
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112522 Design of Laminated Rubber Bearing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11253 Design of Friction Pendulum System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1126 Verification of Properties of Isolation Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11261 Tests for Isolation Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 112611 System Characterization Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 112612 Prototype Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 112613 Quality Control Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11262 Uniform Building Code Recommendations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112621 Units Dependent on Loading Rates
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112622 Units Dependent on Bilateral Load
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112623 System Adequacy
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1127 Analysis of Base-Isolated Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11271 Modeling of a Superstructure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11272 Modeling of Isolation System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11273 Static Analysis Procedure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11274 Dynamic Analysis Procedure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 112741 Response Spectrum Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 112742 Time-History Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11275 Software for Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1128 Experimental Methods for Isolated Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1129 Implementation of Seismic Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11291 New Construction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112911 Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112912 Bridges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11292 Seismic Retrofit
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112921 Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112922 Bridges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11293 Other Implementations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 11210 Performance during Past Earthquakes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 112101 Performance of Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 112102 Performance of Bridges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 113 Seismic Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1131 Historical Development of Seismic Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1132 Basic Principles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11321 Passive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11322 Active Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11323 Semiactive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11324 Hybrid Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11325 Categorization of Basic Principles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1133 Important Issues in Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11331 SoilndashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11332 DevicendashStructure Interaction and Time Delay
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11333 Design Guidelines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1134 Vibration-Control Devices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11341 Passive Control Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113411 Metallic Yielding Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113412 Friction Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113413 Viscoelastic Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113414 Viscous Fluid Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113415 Tuned Mass Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11342 Active Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113421 Electromagnetic Actuator
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113422 Hydraulic Actuators
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11343 Semiactive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113431 Variable-Orifice Hydraulic Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113432 Controllable Fluid Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113433 Controllable Friction Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11344 Hybrid Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1135 Control Algorithm
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11351 Active Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11352 Semiactive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113521 Common Control Schemes for Controllable Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113522 Special Control Schemes for Controllable Damper
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1136 Experimental Performance Verification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11361 Shaking Table Tests of a Flexible Structural Model with TMD AMD and ATMD
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11362 Substructure Hybrid Test
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113621 Hybrid Tests Using Hydraulic Actuator
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113622 Hybrid Tests Using Shaking Table
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113623 Hybrid Tests Using Inertia-Force-Driven Loading System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1137 Implementations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11371 Semiactive Control of Full-Scale Structures Using Variable Joint Damper System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113711 Background of Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113712 Test System Set Up
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113713 Control Algorithm
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113714 Test Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11372 Application of Structural Control Technologies to Seismic Retrofit of a Cable-Stayed Bridge
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113721 Background of Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113722 Basic Concept of Seismic Retrofit
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113723 Modal Shape Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113724 Time-History Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113725 Soil ndash Structure Interaction Effect
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113726 Semiactive Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53191ch12
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Chapter 12 Seismic Random Vibration of Long-Span Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 121 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1211 Basic Concepts of Random Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12111 Stationary Random Process
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12112 Nonstationary Random Process
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1212 Three Methods for Structural Seismic Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12121 Response Spectrum Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12122 Time-History Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12123 Random Vibration Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 121231 Davenport Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 121232 Vanmarcke Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 12124 Comparisons of the Three Seismic-Analysis Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 122 Seismic Random-Excitation Fields
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1221 Power Spectral Density of Spatially Varying Ground Acceleration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1222 Several Coherence Models
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12221 FengndashHu Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12222 Harichandran ndashVanmarcke Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12223 LohndashYeh Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12224 OliveirandashHaondashPenzien Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12225 LucondashWong Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12226 QundashWangndashWang Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1223 Generation of Ground Acceleration Power Spectral Density Curves from Acceleration Response Spectrum Curves
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12231 Kaul Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12232 Iteration Scheme
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1224 Seismic Equations of Motion of Long-Span Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1225 Seismic Waves and Their Geometrical Expressions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 123 Pseudoexcitation Method for Structural Random Vibration Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1231 Structures Subjected to Stationary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12311 Single Stationary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12312 Multiple Stationary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1232 Structures Subjected to Nonstationary Random Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12321 Structures Subjected to Uniformly Modulated Evolutionary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 123211 Single Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 123212 Multiple Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12322 Structures Subjected to Nonuniformly Modulated Evolutionary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 123221 Single Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 123222 Multiple Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1233 Precise Integration Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12331 Precise Integration of Exponential Matrices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12332 Particular Solutions and Precise Integration Formulas for Various Forms of Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 123321 Linear Loading Form (HPD-L Form)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 123322 Sinusoidal Loading Form (HPD-S Form)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 123323 Exponentially Decaying Sinusoidal Loading Form (HPD-E Form)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 124 Long-Span Structures Subjected to Stationary Random Ground Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1241 The Solution of Equations of Motion Using the Pseudoexcitation Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1242 Numerical Comparisons with Other Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12421 Song-Hua-Jiang Suspension Bridge
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 124211 All Supports Move Uniformly
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 124212 Wave Passage Effect Is Taken into Account
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 124213 Wave-Passage Effect and Incoherence Effect Are Jointly Taken into Account
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 12422 San Joaquin Concrete Bridge
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 125 Long-Span Structures Subjected to Nonstationary Random Ground Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1251 Modulation Functions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1252 The Formulas for Nonstationary Multiexcitation Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1253 Expected Extreme Values of Nonstationary Random Processes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1254 Numerical Comparisons with the Corresponding Stationary Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 126 Conclusions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Related Titles
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                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Chapter 13 Seismic Qualification of Equipment
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 131 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 132 Distribution Qualification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1321 Drive-Signal Generation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1322 Distribution Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1323 Test Procedures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 133 Seismic Qualification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1331 Stages of Seismic Qualification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1332 Test Preliminaries
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1333 Single-Frequency Testing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1334 Multifrequency Testing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1335 Generation of RRS Specifications
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Bibliography
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                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Chapter 14 Human Response to Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 141 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 142 Vibration Excitations on Humans
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1421 Excitation Characteristics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 143 Human Response to Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1431 Vibration Perception
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1432 Frequency Weighting Curve
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1433 Iso-Perception Curves
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1434 Detection Threshold Curve
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 144 Regulation of Human Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1441 Acceptable Vibration Levels in Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1442 Whole-Body Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1443 HandndashArm Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
Page 9: Vibration Monitoring, Testing, and Instrumentationpreview.kingborn.net › 646000 › d1a74678d91943e5ba1d5e... · The MEMS Handbook, Second Edition MEMS: Introduction and Fundamentals

Contributors

xi

Kourosh DanaiUniversity of Massachusetts

Amherst Massachusetts

Clarence W de SilvaThe University of British Columbia

Vancouver British Columbia Canada

P S HeynsUniversity of Pretoria

Pretoria South Africa

S HuangNational University of Singapore

Singapore

Hirokazu IemuraKyoto University

Kyoto Japan

Sarvesh Kumar JainMadhav Institute of Technology and

Science

Madhya Pradesh India

Christian LalanneEngineering Consultant

Jalles France

TH LeeNational University of Singapore

Singapore

YP LeowSingapore Institute of Manufacturing

Technology

Singapore

SY LimSingapore Institute of Manufacturing

Technology

Singapore

Jiaohao LinDalian University of Technology

Liaoning Peoplersquos Republic of China

W LinSingapore Institute of Manufacturing

Technology

Singapore

Chris K MechefskeQueenrsquos University

Kingston Ontario Canada

Priyan MendisUniversity of Melbourne

Melbourne Victoria Australia

Tuan NgoUniversity of Melbourne

Melbourne Victoria Australia

Mulyo Harris PradonoKyoto University

Kyoto Japan

C SchefferUniversity of Stellenbosch

Pretoria South Africa

KK TanNational University of Singapore

Singapore

KZ TangNational University of Singapore

Singapore

Yahui ZhangDalian University of Technology

Liaoning Peoplersquos Republic of China

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copy 2007 by Taylor amp Francis Group LLC

Contents

1 Vibration Instrumentation Clarence W de Silva 1-1

11 Introduction 1-1

12 Vibration Exciters 1-3

13 Control System 1-15

14 Performance Specification 1-21

15 Motion Sensors and Transducers 1-27

16 Torque Force and Other Sensors 1-50

Appendix 1A Virtual Instrumentation for Data Acquisition Analysis

and Presentation 1-73

2 Signal Conditioning and Modification Clarence W de Silva 2-1

21 Introduction 2-2

22 Amplifiers 2-2

23 Analog Filters 2-15

24 Modulators and Demodulators 2-29

25 AnalogndashDigital Conversion 2-37

26 Bridge Circuits 2-43

27 Linearizing Devices 2-49

28 Miscellaneous Signal Modification Circuitry 2-56

29 Signal Analyzers and Display Devices 2-62

3 Vibration Testing Clarence W de Silva 3-1

31 Introduction 3-1

32 Representation of a Vibration Environment 3-3

33 Pretest Procedures 3-24

34 Testing Procedures 3-37

35 Some Practical Information 3-52

4 Experimental Modal Analysis Clarence W de Silva 4-1

41 Introduction 4-1

42 Frequency-Domain Formulation 4-2

43 Experimental Model Development 4-8

44 Curve Fitting of Transfer Functions 4-10

45 Laboratory Experiments 4-18

46 Commercial EMA Systems 4-24

xiii

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copy 2007 by Taylor amp Francis Group LLC

5 Mechanical Shock Christian Lalanne 5-1

51 Definitions 5-2

52 Description in the Time Domain 5-3

53 Shock Response Spectrum 5-4

54 Pyroshocks 5-17

55 Use of Shock Response Spectra 5-18

56 Standards 5-24

57 Damage Boundary Curve 5-26

58 Shock Machines 5-28

59 Generation of Shock Using Shakers 5-44

510 Control by a Shock Response Spectrum 5-52

511 Pyrotechnic Shock Simulation 5-58

6 Machine Condition Monitoring and Fault Diagnostics Chris K Mechefske 6-1

61 Introduction 6-2

62 Machinery Failure 6-2

63 Basic Maintenance Strategies 6-4

64 Factors Which Influence Maintenance Strategy 6-7

65 Machine Condition Monitoring 6-8

66 Transducer Selection 6-10

67 Transducer Location 6-14

68 Recording and Analysis Instrumentation 6-14

69 Display Formats and Analysis Tools 6-16

610 Fault Detection 6-21

611 Fault Diagnostics 6-25

7 Vibration-Based Tool Condition Monitoring Systems C Scheffer and PS Heyns 7-1

71 Introduction 7-1

72 Mechanics of Turning 7-2

73 Vibration Signal Recording 7-7

74 Signal Processing for Sensor-Based Tool Condition Monitoring 7-11

75 Wear ModelDecision-Making for Sensor-Based Tool Condition Monitoring 7-15

76 Conclusion 7-20

8 Fault Diagnosis of Helicopter Gearboxes Kourosh Danai 8-1

81 Introduction 8-1

82 Abnormality Scaling 8-5

83 The Structure-Based Connectionist Network 8-8

84 Sensor Location Selection 8-11

85 A Case Study 8-14

86 Conclusion 8-23

9 Vibration Suppression and Monitoring in Precision Motion Systems KK Tan

TH Lee KZ Tang S Huang SY Lim W Lin and YP Leow 9-1

91 Introduction 9-1

92 Mechanical Design to Minimize Vibration 9-2

93 Adaptive Notch Filter 9-10

94 Real-Time Vibration Analyzer 9-17

Contentsxiv

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copy 2007 by Taylor amp Francis Group LLC

95 Practical Insights and Case Study 9-29

96 Conclusions 9-35

10 Vibration and Shock Problems of Civil Engineering Structures Priyan Mendis

and Tuan Ngo 10-1

101 Introduction 10-2

102 Earthquake-Induced Vibration of Structures 10-3

103 Dynamic Effects of Wind Loading on Structures 10-22

104 Vibrations Due to FluidndashStructure Interaction 10-33

105 Blast Loading and Blast Effects on Structures 10-34

106 Impact Loading 10-47

107 Floor Vibration 10-51

11 Seismic Base Isolation and Vibration Control Hirokazu Iemura Sarvesh Kumar Jain

and Mulyo Harris Pradono 11-1

111 Introduction 11-1

112 Seismic Base Isolation 11-4

113 Seismic Vibration Control 11-33

12 Seismic Random Vibration of Long-Span Structures Jiahao Lin and Yahui Zhang 12-1

121 Introduction 12-2

122 Seismic Random-Excitation Fields 12-11

123 Pseudoexcitation Method for Structural Random Vibration Analysis 12-16

124 Long-Span Structures Subjected to Stationary Random Ground Excitations 12-27

125 Long-Span Structures Subjected to Nonstationary Random Ground Excitations 12-34

126 Conclusions 12-39

13 Seismic Qualification of Equipment Clarence W de Silva 13-1

131 Introduction 13-1

132 Distribution Qualification 13-1

133 Seismic Qualification 13-6

14 Human Response to Vibration Clarence W de Silva 14-1

141 Introduction 14-1

142 Vibration Excitations on Humans 14-2

143 Human Response to Vibration 14-3

144 Regulation of Human Vibration 14-6

Contents xv

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copy 2007 by Taylor amp Francis Group LLC

1Vibration

Instrumentation

Clarence W de SilvaThe University of British Columbia

11 Introduction 1-1

12 Vibration Exciters 1-3Shaker Selection dagger Dynamics of Electromagnetic Shakers

13 Control System 1-15Components of a Shaker Controller dagger Signal-Generating

Equipment

14 Performance Specification 1-21Parameters for Performance Specification dagger Linearity dagger

Instrument Ratings dagger Accuracy and Precision

15 Motion Sensors and Transducers 1-27Potentiometer dagger Variable-Inductance Transducers dagger

Mutual-Induction Proximity Sensor dagger Selfinduction

Transducers dagger Permanent-Magnet Transducers dagger

Alternating Current Permanent-Magnet Tachometer dagger

Alternating Current Induction Tachometer dagger Eddy Current

Transducers dagger Variable-Capacitance Transducers dagger

Piezoelectric Transducers

16 Torque Force and Other Sensors 1-50Strain Gage Sensors dagger Miscellaneous Sensors

Appendix 1A Virtual Instrumentation for DataAcquisition Analysis and Presentation 1-73

Summary

Devices useful in instrumenting a mechanical vibrating system are presented in this chapter Shakers whichgenerate vibration excitations are discussed and compared A variety of sensors including motion sensorsproximity sensors forcetorque sensors and other miscellaneous sensors are considered Performance specificationin the time domain and the frequency domain is addressed Rating parameters of instruments are given

11 Introduction

Measurement and associated experimental techniques play a significant role in the practice of vibration

Academic exposure to vibration instrumentation usually arises in laboratories in the context of learning

training and research In vibration practice perhaps the most important task of instrumentation is the

measurement or sensing of vibration Vibration sensing is useful in the following applications

1 Design and development of a product

2 Testing (screening) of a finished product for quality assurance

3 Qualification of a good-quality product to determine its suitability for a specific application

1-1

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copy 2007 by Taylor amp Francis Group LLC

4 Mechanical aging of a product prior to carrying out a test program

5 Exploratory testing of a product to determine its dynamic characteristics such as resonances

mode shapes and even a complete dynamic model

6 Vibration monitoring for performance evaluation

7 Control and suppression of vibration

Figure 11 indicates a procedure typical of experimental vibration highlighting the essential

instrumentation Vibrations are generated in a device the test object in response to some excitation In

some experimental procedures primarily in vibration testing (see Figure 11) the excitation signal has

to be generated in a signal generator in accordance with some requirement (specification) and applied to

the object through an exciter after amplification and conditioning In some other situations primarily in

performance monitoring and vibration control the excitations are generated as an integral part of the

operating environment of the vibrating object and may originate either within the object (eg engine

excitations in an automobile) or in the environment with which the object interacts during operation

(eg road disturbances on an automobile) Sensors are needed to measure vibrations in the test object In

particular a control sensor is used to check whether the specified excitation is applied to the object

and one or more response sensors may be used to measure the resulting vibrations at key locations of

the object

The sensor signals have to be properly conditioned for example by filtering and amplification and

modified for example through modulation demodulation and analog-to-digital conversion prior to

recording analyzing and display The purpose of the controller is to guarantee that the excitation is

correctly applied to the test object If the signal from the control sensor deviates from the required

excitation the controller modifies the signal to the exciter so as to reduce this deviation Furthermore the

controller will stabilize or limit (compress) the vibrations in the object It follows that instruments in

experimental vibration may be generally classified into the following categories

1 Signal-generating devices

2 Vibration exciters

3 Sensors and transducers

4 Signal conditioningmodifying devices

5 Signal analysis devices

6 Control devices

7 Vibration recording and display devices

AnalogDigital

Interface

DigitalSignal

RecorderAnalyzerDisplay

FilterAmplifier

FilterAmplifier

SignalGenerator

and ExciterController

Reference (Required)Signal (Specification)

PowerAmplifier

MountingFixtures

TestObject

ResponseSensor

ControlSensor

Exciter

SwivelBase

FIGURE 11 Typical instrumentation in experimental vibration

Vibration Monitoring Testing and Instrumentation1-2

53191mdash522007mdash1201mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

Note that one instrument may perform the tasks

of more than one category listed here Also more

than one instrument may be needed to carry out

tasks in a single category In the following sections

we will provide some examples of the types of

vibration instrumentation giving characteristics

operating principles and important practical

considerations Also we will describe several

experiments which can be found in a typical

vibration laboratory

An experimental vibration system generally

consists of four main subsystems

1 Test object

2 Excitation system

3 Control system

4 Signal acquisition and modification system

These are schematically shown in Figure 12 Note that various components shown in Figure 11 may

be incorporated into one of these subsystems In particular component matching hardware and object

mounting fixtures may be considered interfacing devices that are introduced through the interaction

between the main subsystems as shown in Figure 12 Some important issues of vibration testing and

instrumentation are summarized in Box 11

12 Vibration Exciters

Vibration experimentation may require an external exciter to generate the necessary vibration This is the

case in controlled experiments such as product testing where a specified level of vibration is applied to the

test object and the resulting response is monitored A variety of vibration exciters are available with

different capabilities and principles of operation

Three basic types of vibration exciters (shakers) are widely used hydraulic shakers inertial shakers

and electromagnetic shakers The operation-capability ranges of typical exciters in these three categories

are summarized in Table 11 Stroke or maximum displacement is the largest displacement the exciter

is capable of imparting onto a test object whose weight is assumed to be within its design load limit

Maximum velocity and acceleration are similarly defined Maximum force is the largest force that could

be applied by the shaker to a test object of acceptable weight (one within the design load) The values

given in Table 11 should be interpreted with caution Maximum displacement is achieved only at very

low frequencies The achievement of maximum velocity corresponds to intermediate frequencies in the

operating frequency range of the shaker Maximum acceleration and force ratings are usually achieved at

high frequencies It is not feasible for example to operate a vibration exciter at its maximum

displacement and its maximum acceleration simultaneously

Consider a loaded exciter that is executing harmonic motion Its displacement is given by

x frac14 s sin vt eth11THORN

in which s is the displacement amplitude (or stroke) Corresponding velocity and acceleration are

_x frac14 sv cos vt eth12THORN

eurox frac14 2sv2sin vt eth13THORN

SignalModification

System

TestObject

ControlSystem

VibrationExciter (Shaker)

System

FIGURE 12 Interactions between major subsystems of

an experimental vibration system

Vibration Instrumentation 1-3

53191mdash522007mdash1201mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

If the velocity amplitude is denoted by v and the acceleration amplitude by a it follows from Equation

12 and Equation 13 thatv frac14 vs eth14THORN

and

a frac14 vv eth15THORN

Box 11

VIBRATION INSTRUMENTATION

Vibration Testing Applications for Products

Design and Development Production Screening and Quality Assessment Utilization and Qualification for Special Applications

Testing Instrumentation

Exciter (excites the test object) Controller (controls the exciter for accurate excitation) Sensors and Transducers (measure excitations and responses and provide excitation error

signals to controller) Signal Conditioning (converts signals to appropriate form) Recording and Display (perform processing storage and documentation)

Exciters

Shakers

1 Electrodynamic (high bandwidth moderate power complex and multifrequency

excitations)

2 Hydraulic (moderate to high bandwidth high power complex and multifrequency

excitations)

3 Inertial (low bandwidth low power single-frequency harmonic excitations)

TransientInitial Condition

1 Hammers (impulsive bump tests)

2 Cable Release (step excitations)

3 Drop (impulsive)

Signal Conditioning

Filters Amplifiers Amplifiers ModulatorsDemodulators ADCDAC

Sensors

Motion (displacement velocity acceleration) Force (strain torque)

Vibration Monitoring Testing and Instrumentation1-4

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copy 2007 by Taylor amp Francis Group LLC

TABLE 11 Typical Operation-Capability Ranges for Various Shaker Types

Shaker Type Typical Operational Capabilities

Frequency Maximum Displacement

(Stroke)

Maximum

Velocity

Maximum

Acceleration

Maximum

Force

Excitation

Waveform

Hydraulic

(electrohydraulic)

Low

(01ndash500 Hz)

High (20 in 50 cm) Intermediate

(50 insec

125 cmsec)

Intermediate

(20 g)

High (100000 lbf

450000 N)

Average flexibility (simple

to complex and random)

Inertial

(counter-rotating mass)

Intermediate

(2ndash50 Hz)

Low (1 in 25 cm) Intermediate

(50 insec

125 cmsec)

Intermediate

(20 g)

Intermediate

(1000 lbf 4500 N)

Sinusoidal only

Electromagnetic

(electrodynamic)

High

(2ndash10000 Hz)

Low (1 in 25 cm) Intermediate

(50 insec

125 cmsec)

High (100 g) Low to intermediate

(450 lbf 2000 N)

High flexibility and accuracy

(simple to complex and

random)

VibrationInstru

mentation

1-5

53191mdash522007mdash

1201mdashSENTHILKUMARmdash246494mdash

CRCndashpp1ndash112

copy 2007 by Taylor amp Francis Group LLC

An idealized performance curve of a shaker

has a constant displacementndashamplitude region a

constant velocityndashamplitude region and a con-

stant accelerationndashamplitude region for low

intermediate and high frequencies respectively

in the operating frequency range Such an ideal

performance curve is shown in Figure 13(a) on a

frequencyndashvelocity plane Logarithmic axes are

used In practice typical shaker performance

curves would be fairly smooth yet nonlinear

curves similar to those shown in Figure 13(b)

As the mass increases the performance curve

compresses Note that the acceleration limit of a

shaker depends on the mass of the test object

(load) Full load corresponds to the heaviest object

that could be tested The ldquono loadrdquo condition

corresponds to a shaker without a test object To

standardize the performance curves they are

usually defined at the rated load of the shaker A

performance curve in the frequencyndashvelocity

plane may be converted to a curve in the

frequencyndashacceleration plane simply by increasing

the slope of the curve by a unit magnitude (ie

20 dbdecade)

Several general observations can be made from

Equation 14 and Equation 15 In the constant-

peak displacement region of the performance

curve the peak velocity increases proportionally

with the excitation frequency and the peak

acceleration increases with the square of the excitation frequency In the constant-peak velocity region

the peak displacement varies inversely with the excitation frequency and the peak acceleration increases

proportionately In the constant-peak acceleration region the peak displacement varies inversely with the

square of the excitation frequency and the peak velocity varies inversely with the excitation frequency

This further explains why rated stroke maximum velocity and maximum acceleration values are not

simultaneously realized

121 Shaker Selection

Vibration testing is accomplished by applying a specified excitation to the test package using a shaker

apparatus and monitoring the response of the test object Test excitation may be represented by its

response spectrum The test requires that the response spectrum of the actual excitation known as the

test response spectrum (TRS) envelops the response spectrum specified for the particular test known as

the required response spectrum (RRS)

A major step in the planning of any vibration testing program is the selection of a proper shaker

(exciter) system for a given test package The three specifications that are of primary importance in

selecting a shaker are the force rating the power rating and the stroke (maximum displacement) rating

Force and power ratings are particularly useful in moderate to high frequency excitations and the stroke

rating is the determining factor for low frequency excitations In this section a procedure is given to

determine conservative estimates for these parameters in a specified test for a given test package

Frequency domain considerations are used here

Stroke

Limit M

ax

Acceleration

MaxVelocity

Peak

Vel

ocity

(cm

s)

01 1 10 100

FullLoad

NoLoad

Frequency (Hz)(a)

Peak

Vel

ocity

(cm

s)

100

10

1

100

10

1

01 1 10 100

FullLoad

NoLoad

Frequency (Hz)(b)

FIGURE 13 Performance curve of a vibration exciter

in the frequencyndashvelocity plane (log) (a) ideal (b)

typical

Vibration Monitoring Testing and Instrumentation1-6

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copy 2007 by Taylor amp Francis Group LLC

1211 Force Rating

In the frequency domain the (complex) force at the exciter (shaker) head is given by

F frac14 mHethvTHORNasethvTHORN eth16THORNin which v is the excitation frequency variable m is the total mass of the test package including

mounting fixture and attachments asethvTHORN is the Fourier spectrum of the support-location (exciter head)

acceleration and H(v) is frequency response function that takes into account the flexibility and

damping effects (dynamics) of the test package apart from its inertia In the simplified case where the

test package can be represented by a simple oscillator of natural frequency vn and damping ratio by zt

this function becomes

HethvTHORN frac14 1thorn 2jztv=vn=12 ethv=vnTHORN2 thorn 2jztv=vn eth17THORNin which j frac14 ffiffiffiffi

21p

This approximation is adequate for most practical purposes The static weight of the

test object is not included in Equation 16 Most heavy-duty shakers which are typically hydraulic

have static load support systems such as pneumatic cushion arrangements that can exactly balance the

dead load The exciter provides only the dynamic force In cases where shaker directly supports the

gravity load in the vertical test configuration Equation 16 should be modified by adding a term to

represent this weight

A common practice in vibration test applications is to specify the excitation signal by its response

spectrum This is simply the peak response of a simple oscillator expressed as a function of its natural

frequency when its support location is excited by the specified signal Clearly the damping of the simple

oscillator is an added parameter in a response spectrum specification Typical damping ratios ethzrTHORN used inresponse spectra specifications are less than 01 (or 10) It follows that an approximate relationship

between the Fourier spectrum of the support acceleration and its response spectrum is

as frac14 2jzrarethvTHORN eth18THORNThe magnitude larethvTHORNl is the response spectrumEquation 18 substituted into Equation 16 gives

F frac14 mHethvTHORN2jzrarethvTHORN eth19THORNIn view of Equation 17 for test packages having low damping the peak value of H(v) is

approximately 1=eth2jztTHORN this should be used in computing the force rating if the test package has a

resonance within the frequency range of testing On the other hand if the test package is assumed to be

rigid then HethvTHORN oslash 1 A conservative estimate for the force rating is

Fmax frac14 methzr=ztTHORNlarethvTHORNlmax eth110THORNIt should be noted that larethvTHORNlmax is the peak value of the specified (required) response spectrum (RRS)

for acceleration

1212 Power Rating

The exciter head does not develop its maximum force when driven at maximum velocity Output power

is determined by using

p frac14 Refrac12FvsethvTHORN eth111THORNin which vsethvTHORN is the Fourier spectrum of the exciter velocity and Re [ ] denotes the real part of a complex

function Note that as frac14 jvvs Substituting Equation 16 and Equation 18 into Equation 111 gives

p frac14 eth4mz2r =vTHORNRefrac12jHethvTHORNa2r ethvTHORN eth112THORNIt follows that a conservative estimate for the power rating is

pmax frac14 2methz2r =ztTHORNfrac12larethvTHORNl2=v max eth113THORN

Vibration Instrumentation 1-7

53191mdash522007mdash1201mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

Representative segments of typical acceleration RRS curves have slope n as given by

a frac14 k1vn eth114THORN

It should be clear from Equation 113 that the maximum output power is given by

pmax frac14 k2v2n21 eth115THORN

This is an increasing function for n 1=2 and a decreasing function for n 1=2 It follows that the power

rating corresponds to the highest point of contact between the acceleration RRS curve and a line of slope

equal to 12 A similar relationship may be derived if velocity RRS curves (having slopes n2 1) are used

1213 Stroke Rating

From Equation 18 it should be clear that the Fourier spectrum xs of the exciter displacement time

history can be expressed as

xs frac14 2zrarethvTHORN=jv2 eth116THORNAn estimate for stroke rating is

xmax frac14 2zrfrac12larethvTHORNl=v2 max eth117THORNThis is of the form

xmax frac14 kvn22 eth118THORNIt follows that the stroke rating corresponds to the highest point of contact between the acceleration

RRS curve and a line of slope equal to two

Example 11

A test package of overall mass 100 kg is to be

subjected to dynamic excitation represented by the

acceleration RRS (at 5 damping) as shown in

Figure 14 The estimated damping of the test

package is 7 The test package is known to have a

resonance within the frequency range of the

specified test Determine the exciter specifications

for the test

Solution

From the development presented in the previous

section it is clear that the point F (or P) in

Figure 14 corresponds to the force and output

power ratings and the point S corresponds to

the stroke rating The co-ordinates of these

critical points are F P frac14 eth42 Hz 40 gTHORN and S frac14 eth08 Hz 075 gTHORN Equation 110 gives the force

rating as

Fmax frac14 100 pound eth005=007THORN pound 40 pound 981 N frac14 2803 N

Equation 113 gives the power rating as

pmax frac14 2 pound 100 pound eth0052=007THORN pound frac12eth40 pound 981THORN2=42 pound 2p watts frac14 417 W

Equation 117 gives the stroke rating as

xmax frac14 2 pound 005 pound frac12eth075 pound 98THORN=eth08 pound 2pTHORN2 m frac14 3 cm

Acc

eler

atio

n(g

)

Con

stan

t Dis

plac

emen

t

Constant Velo

city

Frequency (Hz)

S

FP

0101

10 10 100

10

10

FIGURE 14 Test excitation specified by an accelera-

tion RRS (5 damping)

Vibration Monitoring Testing and Instrumentation1-8

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copy 2007 by Taylor amp Francis Group LLC

1214 Hydraulic Shakers

A typical hydraulic shaker consists of a piston-cylinder arrangement (also called a ram) a servo-valve a

fluid pump and a driving electric motor Hydraulic fluid (oil) is pressurized (typical operating pressure

4000 psi) and pumped into the cylinder through a servo-valve by means of a pump that is driven by an

electric motor (typical power 150 hp) The flow (typical rate 100 galmin) that enters the cylinder is

controlled (modulated) by the servo-valve which in effect controls the resulting piston (ram) motion

A typical servo-valve consists of a two-stage spool valve which provides a pressure difference and a

controlled (modulated) flow to the piston which sets it in motion

The servo-valve itself is moved by means of a linear torque motor which is driven by the excitation-

input signal (electrical) A primary function of the servo-valve is to provide a stabilizing feedback to the

ram In this respect the servo-valve complements the main control system of the test setup The ram is

coupled to the shaker table by means of a link with some flexibility The cylinder frame is mounted on the

support foundation with swivel joints This allows for some angular and lateral misalignment which

might be caused primarily by test-object dynamics as the table moves

Two-degree-of-freedom (Two-DoF) testing requires two independent sets of actuators and three-DoF

testing requires three independent actuator sets Each independent actuator set can consist of several

actuators operated in parallel using the same pump and the same excitation-input signal to the torque

motors

If the test table is directly supported on the vertical actuators they must withstand the total dead

weight (ie the weight of the test table the test object the mounting fixtures and the instrumentation)

This is requirement is usually prevented by providing a pressurized air cushion in the gap between the

test table and the foundation walls Air should be pressurized so as to balance the total dead weight

exactly (typical required gage pressure 3 psi)

Figure 15(a) shows the basic components of a typical hydraulic shaker The corresponding

operational block diagram is shown in Figure 15(b) It is desirable to locate the actuators in a pit in the

test laboratory so that the test tabletop is flushed with the test laboratory floor under no-load conditions

This minimizes the effort required to place the test object on the test table Otherwise the test object has

to be lifted onto the test table with a forklift Also installation of an aircushion to support the system

dead weight is difficult under these circumstances of elevated mounting

Hydraulic actuators are most suitable for heavy load testing and are widely used in industrial and civil

engineering applications They canbeoperated at very low frequencies (almost direct current [DC]) aswell

as at intermediate frequencies (see Table 11) Large displacements (stroke) are possible at low frequencies

Hydraulic shakers have the advantage of providing high flexibility of operation during the test their

capabilities include variable-force and constant-force testing and wide-band random-input testing The

velocity and acceleration capabilities of hydraulic shakers are moderate Although any general excitation-

input motion (for example sine wave sine beat wide-band random) can be used in hydraulic shakers

faithful reproduction of these signals is virtually impossible at high frequencies because of distortion and

higher-order harmonics introduced by the high noise levels that are common in hydraulic systems This

is only a minor drawback in heavy-duty intermediate-frequency applications Dynamic interactions are

reduced through feedback control

1215 Inertial Shakers

In inertial shakers or ldquomechanical excitersrdquo the force that causes the shaker-table motion is generated by

inertia forces (accelerating masses) Counter-rotating-mass inertial shakers are typical in this category

To understand their principle of operation consider two equal masses rotating in opposite directions at

the same angular speed v and in the same circle of radius r (see Figure 16) This produces a resultant

force equal to 2mv2r cos vt in a fixed direction (the direction of symmetry of the two rotating arms)

Consequently a sinusoidal force with a frequency of v and an amplitude proportional to v2 is generated

This reaction force is applied to the shaker table

Figure 17 shows a sketch of a typical counter-rotating-mass inertial shaker It consists of two identical

rods rotating at the same speed in opposite directions Each rod has a series of slots in which to

Vibration Instrumentation 1-9

53191mdash522007mdash1201mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

place weights In this manner the magnitude of

the eccentric mass can be varied to achieve various

force capabilities The rods are driven by a

variable-speed electric motor through a gear

mechanism that usually provides several speed

ratios A speed ratio is selected depending on the

required test-frequency range The whole system is

symmetrically supported on a carriage that is

directly connected to the test table The test object

is mounted on the test table The preferred

mounting configuration is horizontal so that the

excitation force is applied to the test object in a

horizontal direction In this configuration there

are no variable gravity moments (weight pounddistance to center of gravity) acting on the drive

mechanism Figure 17 shows the vertical con-

figuration In dynamic testing of large structures

the carriage can be mounted directly on the

structure at a location where the excitation force

should be applied By incorporating two pairs of

counter-rotating masses it is possible to generate

test moments as well as test forces

FIGURE 15 A typical hydraulic shaker arrangement (a) schematic diagram (b) operational block diagram

m m

2mw2r cos wt

wtw w

wt

FIGURE 16 Principle of operation of a counter-

rotating-mass inertial shaker

Vibration Monitoring Testing and Instrumentation1-10

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copy 2007 by Taylor amp Francis Group LLC

Reaction-type shakers driven by inertia are widely used for the prototype testing of civil engineering

structures Their first application dates back to 1935 Inertial shakers are capable of producing

intermediate excitation forces The force generated is limited by the strength of the carriage frame The

frequency range of operation and the maximum velocity and acceleration capabilities are also

intermediate for inertial shakers whereas the maximum displacement capability is typically low A major

limitation of inertial shakers is that their excitation force is exclusively sinusoidal and that the force

amplitude is directly proportional to the square of the excitation frequency As a result complex and

random excitation testing constant-force testing (for example transmissibility tests and constant-force

sine-sweep tests) and flexibility to vary the force amplitude or the displacement amplitude during a test

are not generally feasible with this type of shakers Excitation frequency and amplitude can be varied

during testing however by incorporating a variable-speed drive for the motor The sinusoidal excitation

generated by inertial shakers is virtually undistorted which gives them an advantage over the other types

of shakers when used in sine-dwell and sine-sweep tests Small portable shakers with low-force capability

are available for use in on-site testing

1216 Electromagnetic Shakers

In electromagnetic shakers or ldquoelectrodynamic excitersrdquo the motion is generated using the principle of

operation of an electric motor Specifically the excitation force is produced when a variable excitation

signal (electrical) is passed through a moving coil placed in a magnetic field

The components of a commercial electromagnetic shaker are shown in Figure 18 A steady magnetic

field is generated by a stationary electromagnet that consists of field coils wound on a ferromagnetic base

that is rigidly attached to a protective shell structure The shaker head has a coil wound around it When

the excitation electrical signal is passed through this drive coil the shaker head which is supported on

flexure mounts will be set in motion The shaker head consists of the test table on which the test object

is mounted Shakers with interchangeable heads are available The choice of appropriate shaker head is

based on the geometry and mounting features of the test object The shaker head can be turned to

different angles by means of a swivel joint In this manner different directions of excitation (in biaxial

and triaxial testing) can be obtained

FIGURE 17 Sketch of a counter-rotating-mass inertial shaker

Vibration Instrumentation 1-11

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copy 2007 by Taylor amp Francis Group LLC

122 Dynamics of Electromagnetic Shakers

Consider a single axis electromagnetic shaker (Figure 18) with a test object having a single natural

frequency of importance within the test frequency range The dynamic interactions between the shaker

and the test object give rise to two significant natural frequencies (and correspondingly two significant

resonances) These appear as peaks in the frequency response curve of the test setup Furthermore the

natural frequency (resonance) of the test package alone causes a ldquotroughrdquo or depression (antiresonance)

in the frequency response curve of the overall test setup To explain this characteristic consider the

dynamic model shown in Figure 19 The following mechanical parameters are defined for

Figure 19(a) m k and b are the mass stiffness and equivalent viscous damping constant respectively

of the test package and me ke and be are the corresponding parameters of the exciter (shaker) Also in

the equivalent electrical circuit of the shaker head as shown in Figure 19(b) the following electrical

parameters are defined Re and Le are the resistance and (leakage) inductance and kb is the back

electromotive force (back emf) of the linear motor Assuming that the gravitational forces are supported

FIGURE 18 Schematic sectional view of a typical electromagnetic shaker manufactured by Bruel and Kjaer

Denmark

Vibration Monitoring Testing and Instrumentation1-12

53191mdash522007mdash1202mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

by the static deflections of the flexible elements and that the displacements are measured from the static

equilibrium position we have the following system equations

Test object meuroy frac14 2kethy2 yeTHORN2 beth_y2 _yeTHORN eth119THORNShaker head me euroye frac14 fe thorn kethy2 yeTHORN thorn beth_y2 _yeTHORN2 key 2 be _ye eth120THORN

Electrical Lediedt

thorn Reie thorn kb _ye frac14 vethtTHORN eth121THORN

The electromagnetic force fe generated in the shaker head is a result of the interaction of the magnetic

field generated by the current ie with coil of the moving shaker head and the constant magnetic field

(stator) in which the head coil is located Here we have

fe frac14 kbie eth122THORNNote that v(t) is the voltage signal that is applied by the amplifier to the shaker coil ye is the displacement

of the shaker head and y is the displacement response of the test package

It is assumed that kb has consistent electrical and mechanical units (Vmsec and NA) Usually

the electrical time constant of the shaker is quite small compared with the primarily mechanical

time constants of the shaker and the test package In such cases the Ledie=dt term in Equation 121 may

be neglected Consequently the equations from Equation 119 through Equation 122 may be

expressed in the Laplace (frequency) domain with the Laplace variable s taking the place of the derivative

d=dt as

ethms2 thorn bsthorn kTHORNy frac14 ethbsthorn kTHORNye eth123THORN

FIGURE 19 Dynamic models of an electromagnetic shaker and a flexible test package (a) mechanical model

(b) electrical model

Vibration Instrumentation 1-13

53191mdash522007mdash1202mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

frac12mes2 thorn ethbthorn beTHORNsthorn ethkthorn keTHORN ye frac14 ethbsthorn kTHORNy thorn kb

Rev2

k2bs

Reye eth124THORN

It follows that the transfer function of the shaker head motion with respect to the excitation voltage is

given by

yevfrac14 kb

Re

DethsTHORNDdethsTHORN eth125THORN

where DethsTHORN is the characteristic function of the primary dynamics of the test object

DethsTHORN frac14 ms2 thorn bsthorn k eth126THORN

and DdethsTHORN is the characteristic function of the primary dynamic interactions between the shaker and thetest object

DcethsTHORN frac14 mmes4 thorn frac12methbe thorn bthorn boTHORN thornmeb s

3 thorn frac12methke thorn kTHORN thornmekthorn bethbe thorn boTHORN s2thorn frac12bke thorn ethbe thorn boTHORNk sthorn kke

eth127THORN

where

bo frac14 k2bRe

eth128THORN

It is clear that under low damping conditions DdethsTHORN will produce two resonances as it is fourth order in sand similarly DethsTHORN will produce one antiresonance (trough) corresponding to the resonance of the testobject Note that in the frequency domain s frac14 jv and hence the frequency response function given by

Equation 125 is in fact

yevfrac14 kb

Rb

DethjvTHORNDdethjvTHORN eth129THORN

The magnitude of this frequency response function for a typical test system is sketched in Figure 110

Note that this curve is for the ldquoopen-looprdquo case where there is no feedback from the shaker controller

In practice the shaker controller will be able

to compensate for the resonances and anti-

resonances to some degree depending on its

effectiveness

The main advantages of electromagnetic

shakers are their high frequency range of

operation their high degree of operating flexi-

bility and the high level of accuracy of the

generated shaker motion Faithful reproduction

of complex excitations is possible because of the

advanced electronics and control systems used in

this type of shakers Electromagnetic shakers are

not suitable for heavy-duty applications (large test

objects) however High test-input accelerations

are possible at high frequencies when electromag-

netic shakers are used but their displacement and

velocity capabilities are limited to low or

intermediate values (see Table 11)

100

10

1 10 100Excitation Frequency (Hz)

Antiresonance

Resonance

Shak

erD

ispl

acem

entM

agni

tude

Resonance

1000

FIGURE 110 Frequency response curve of a typical

electromagnetic shaker with a test object

Vibration Monitoring Testing and Instrumentation1-14

53191mdash522007mdash1202mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

1221 Transient Exciters

Other varieties of exciters are commonly used in

transient-type vibration testing In these tests

either an impulsive force or an initial excitation is

applied to the test object and the resulting

response is monitored The excitations and the

responses are ldquotransientrdquo in this case Hammer

test drop tests and pluck tests fall into this

category For example a hammer test may be

conducted by hitting the object with an instru-

mented hammer and then measuring the response

of the object The hammer has a force sensor at its

tip as sketched in Figure 111 A piezoelectric or

strain-gage type force sensor may be used More

sophisticated hammers have impedance heads in

place of force sensors An impedance head

measures force and acceleration simultaneously

The results of a hammer test will depend on many

factors for example the dynamics of the hammer

body how firmly the hammer is held during the

impact how quickly the impact is applied and

whether there are multiple impacts

13 Control System

The two primary functions of the shaker control system in vibration testing are (1) to guarantee that the

specified excitation is applied to the test object and (2) to ensure that the dynamic stability (motion

constraints) of the test setup is preserved An operational block diagram illustrating these control

functions is given in Figure 112 The reference input to the control system represents the desired

excitation force that should be applied to the test object In the absence of any control however the force

reaching the test object will be distorted primarily because of (1) dynamic interactions and

nonlinearities of the shaker the test table the mounting fixtures the auxiliary instruments and the test

object itself (2) noise and errors in the signal generator amplifiers filters and other equipment and (3)

external loads and disturbances acting on the test object and other components (for example external

restraints aerodynamic forces friction) To compensate for these distorting factors response

measurements (displacements velocities acceleration and so on) are made at various locations in the

test setup and are used to control the system dynamics In particular the responses of the shaker the test

table and the test object are measured These responses are used to compare the actual excitation felt by

FIGURE 111 An instrumented hammer used in bump

tests or hammer tests

ExcitationInput

(Reference)

Feedback Paths

DriveSignal

ShakerResponse

TestTable

TestObject

Test ObjectResponse

Test TableResponseExciter

(Shaker)(Ram)

Controllerand

Amplifier

FIGURE 112 Operational block diagram illustrating a general shaker control system

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the test object at the shaker interface with the desired (specified) input The drive signal to the shaker is

modified depending on the error that is present

Two types of control are commonly employed in shaker apparatus simple manual control and

complex automatic control Manual control normally consists of simple open-loop trial-and-error

methods of manual adjustments (or calibration) of the control equipment to obtain a desired dynamic

response The actual response is usually monitored (on an oscilloscope or frequency analyzer screen for

example) during manual-control operations The pretest adjustments in manual control can be very

time-consuming as a result the test object might be subjected to overtesting which could produce

cumulative damage is undesirable and could defeat the test purpose Furthermore the calibration

procedure for the experimental setup must be repeated for each new test object

The disadvantages ofmanual control suggest that automatic control is desirable in complex test schemes

in which high accuracy of testing is desired The first step of automatic control involves automatic

measurement of the system response using control sensors and transducers The measurement is then fed

back into the control system which instantaneously determines the best drive signal to actuate the shaker

in order to get the desired excitation This may be done by either analog or digital methods

Primitive control systems require an accurate mathematical description of the test object This

dependency of the control system on the knowledge of test-object dynamics is clearly undesirable

Performance of a good control system should not be considerably affected by the dynamic interactions

and nonlinearities of the test object or by the nature of the excitation Proper selection of feedback signals

and control-system components can reduce such effects and will make the system robust

In the response-spectrum method of vibration testing it is customary to use displacement control at

low frequencies velocity control at intermediate frequency and acceleration control at high frequencies

This necessitates feedback of displacement velocity and acceleration responses Generally however the

most important feedback is the velocity feedback In sine-sweep tests the shaker velocity must change

steadily over the frequency band of interest In particular the velocity control must be precise near the

resonances of the test object Velocity (speed) feedback has a stabilizing effect on the dynamics which is

desirable This effect is particularly useful in ensuring stability in motion when testing is done near

resonances of lightly damped test objects On the contrary displacement (position) feedback can have a

destabilizing effect on some systems particularly when high feedback gains are used

The controller usually consists of various instruments equipment and computation hardware and

software Often the functions of the data-acquisition and processing system overlap with those of the

controller to some extent As an example consider the digital-controller of vibration testing apparatus

First the responses are measured through sensors (and transducers) filtered and amplified

(conditioned) These data channels may be passed through a multiplexer whose purpose is to select

one data channel at a time for processing Most modern data acquisition hardware does not need a

separate multiplexer to handle multiple signals The analog data are converted into digital data using

analog-to-digital converters (ADCs) The resulting sampled data are stored on a disk or as a block data in

the computer memory The reference input signal (typically a signal recorded on an FM tape) is also

sampled (if it is not already in the digital form) using an ADC and fed into the computer Digital

processing is done on the reference signal and the response data with the objective of computing the

command signal to drive the shaker The digital command signal is converted into an analog signal using

a digital-to-analog converter (DAC) and amplified (conditioned) before it is used to drive the exciter

The nature of the control components depends to a large extent on the nature and objectives of the

particular test to be conducted Some of the basic components in a shaker controller are described in

the following subsections

131 Components of a Shaker Controller

1311 Compressor

A compressor circuit is incorporated in automatic excitation control devices to control the excitation-

input level automatically The level of control depends on the feedback signal from a control sensor and

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the specified (reference) excitation signal Usually the compressor circuit is included in the excitation-

signal generator (for example in a sine generator) The control by this means may be done on the basis of

a single-frequency component (eg the fundamental frequency)

1312 Equalizer (Spectrum Shaper)

Random-signal equalizers are used to shape the spectrum of a random signal in a desired manner In

essence and equalizer consists of a bank of narrow-band filters (for example 80 filters) in parallel over

the operating frequency range By passing the signal through each filter the spectral density (or the mean

square value) of the signal in that narrow frequency band (for example each one-third-octave band) is

determined This is compared with the desired spectral level and automatic adjustment is made in that

filter in case there is an error In some systems response-spectrum analysis is made in place of power

spectral density analysis In that case the equalizer consists of a bank of simple oscillators whose

resonant frequencies are distributed over the operating frequency range of the equalizer The feedback

signal is passed through each oscillator and the peak value of its output is determined This value is

compared with the desired response spectrum value at that frequency If there is an error automatic gain

adjustment is made in the appropriate excitation signal components

Random-noise equalizers are used in conjunction with random signal generators They receive

feedback signals from the control sensors In some digital control systems there are algorithms (software)

that are used to iteratively converge the spectrum of the excitation signal felt by the test object into the

desired spectrum

1313 Tracking Filter

Many vibration tests are based on single-frequency excitations In such cases the control functions

should be performed on the basis of the amplitudes of the fundamental-frequency component of the

signal A tracking filter is simply a frequency-tuned band-pass filter It automatically tunes the center

frequency of its very narrow-band-pass filter to the frequency of a carrier signal Then when a noisy

signal is passed through the tuned filter the output of the filter will be the required fundamental

frequency component in the signal Tracking filters also are useful in obtaining amplitudendashfrequency

plots using an XndashY plotter In such cases the frequency value comes from the signal generator (sweep

oscillator) which produces the carrier signal to the tracking filter The tracking filter then determines the

corresponding amplitude of a signal that is fed into it Most tracking filters have dual channels so that two

signals can be handled (tracked) simultaneously

1314 Excitation Controller (Amplitude Servo-Monitor)

An excitation controller is typically an integral part of the signal generator It can be set so that automatic

sweep between two frequency limits can be performed at a selected sweep rate (linear or logarithmic)

More advanced excitation controllers have the capability of an automatic switch-over between constant-

displacement constant-velocity and constant-acceleration excitation-input control at specified

frequencies over the sweep frequency interval Consequently integrator circuits should be present

within the excitation controller unit to determine velocities and displacements from acceleration signals

Sometimes integration is performed by a separate unit called a vibration meter This unit also offers

the operator the capability of selecting the desired level of each signal (acceleration velocity or

displacement) There is an automatic cut-off level for large displacement values that could result from

noise in acceleration signals A compressor is also a subcomponent of the excitation controller The

complete unit is sometimes known as an amplitude servo-monitor

132 Signal-Generating Equipment

Shakers are force-generating devices that are operated using drive (excitation) signals generated from a

source The excitation-signal source is known as the signal generator Three major types of signal

generators are used in vibration testing applications (1) oscillators (2) random-signal generators and

(3) storage devices In some units oscillators and random-signal generators are combined We shall

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discuss these two generators separately however because of their difference in function It also should be

noted that almost any digital signal (deterministic or random) can be generated by a digital computer

using a suitable computer program the signal eventually can be passed through a DAC to obtain

the corresponding analog signal These lsquodigitalrsquo signal generators along with analog sources such as

magnetic tape players (FM) are classified into the category of storage devices

The dynamic range of equipment is the ratio of the maximum and minimum output levels (expressed

in decibels) at which it is capable of operating without significant error This is an important specification

for many types of equipment particularly for signal-generating devices The output level of the signal

generator should be set to a value within its dynamic range

1321 Oscillators

Oscillators are essentially single-frequency generators Typically sine signals are generated but other

waveforms (such as rectangular and triangular pulses) are also available in most oscillators Normally

an oscillator has two modes of operation (1) sweeping up and down between two frequency limits and

(2) dwelling at a specified frequency In the sweep operation the sweep rate should be specified This can

be done either on a linear scale (Hzmin) or on a logarithmic scale (octavesmin) In the dwell operation

the frequency points (or intervals) should be specified In either case a desired signal level can be chosen

using the gain-control knob An oscillator that is operated exclusively in the sweep mode is called a sweep

oscillator

The early generation of oscillators employed variable inductor-capacitor types of electronic circuits to

generate signals oscillating at a desired frequency The oscillator is tuned to the required frequency by

varying the capacitance or inductance parameters A DC voltage is applied to energize the capacitor

and to obtain the desired oscillating voltage signal which subsequently is amplified and conditioned

Modern oscillators use operational amplifier circuits along with resistor capacitor and semiconductor

(SC) elements Also common are crystal (quartz) parallel-resonance oscillators used to generate voltage

signals accurately at a fixed frequency The circuit is activated using a DC-voltage source Other

frequencies of interest are obtained by passing this high-frequency signal through a frequency converter

The signal is then conditioned (amplified and filtered) Required shaping (for example rectangular

pulse) is obtained using a shape circuit Finally the required signal level is obtained by passing the

resulting signal through a variable-gain amplifier A block diagram of an oscillator illustrating various

stages in the generation of a periodic signal is given in Figure 113

A typical oscillator offers a choice of several (typically six) linear and logarithmic frequency ranges and

a sizable level of control capability (for example 80 dB) Upper and lower frequency limits in a sweep can

be preset on the front panel to any of the available frequency ranges Sweep-rate settings are continuously

DC Voltage

Oscillator

FrequencySpecification

FrequencyConverter

FilterAmplifier

ShaperPeriodicSignal

FrequencyCounter

Fixed-FrequencySignal

Variable-GainOutput

Amplifier

SignalSpecification

LevelSpecification

FIGURE 113 Block diagram of an oscillator-type signal generator

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  • 53191fm
    • Vibration Monitoring Testing and Instrumentation
      • Preface
      • Acknowledgments
      • Editor-in-Chief
      • Contributors
      • Contents
      • Related Titles
          • 53191ch1
            • Table of Contents
            • Chapter 1 Vibration Instrumentation
              • Summary
              • 11 Introduction
              • 12 Vibration Exciters
                • 121 Shaker Selection
                  • 1211 Force Rating
                  • 1212 Power Rating
                  • 1213 Stroke Rating
                  • 1214 Hydraulic Shakers
                  • 1215 Inertial Shakers
                  • 1216 Electromagnetic Shakers
                    • 122 Dynamics of Electromagnetic Shakers
                      • 1221 Transient Exciters
                          • 13 Control System
                            • 131 Components of a Shaker Controller
                              • 1311 Compressor
                              • 1312 Equalizer (Spectrum Shaper)
                              • 1313 Tracking Filter
                              • 1314 Excitation Controller (Amplitude Servo-Monitor)
                                • 132 Signal-Generating Equipment
                                  • 1321 Oscillators
                                  • 1322 Random Signal Generators
                                  • 1323 Tape Players
                                  • 1324 Data Processing
                                      • 14 Performance Specification
                                        • 141 Parameters for Performance Specification
                                          • 1411 Time-Domain Specifications
                                          • 1412 Frequency-Domain Specifications
                                            • 142 Linearity
                                            • 143 Instrument Ratings
                                              • 1431 Rating Parameters
                                                • 144 Accuracy and Precision
                                                  • 15 Motion Sensors and Transducers
                                                    • 151 Potentiometer
                                                      • 1511 Potentiometer Resolution
                                                      • 1512 Optical Potentiometer
                                                        • 152 Variable-Inductance Transducers
                                                          • 1521 Mutual-Induction Transducers
                                                          • 1522 Linear-Variable Differential Transformer
                                                          • 1523 Signal Conditioning
                                                            • 153 Mutual-Induction Proximity Sensor
                                                            • 154 Selfinduction Transducers
                                                            • 155 Permanent-Magnet Transducers
                                                            • 156 Alternating Current Permanent-Magnet Tachometer
                                                            • 157 Alternating Current Induction Tachometer
                                                            • 158 Eddy Current Transducers
                                                            • 159 Variable-Capacitance Transducers
                                                              • 1591 Capacitive Displacement Sensors
                                                              • 1592 Capacitive Angular Velocity Sensor
                                                              • 1593 Capacitance Bridge Circuit
                                                                • 1510 Piezoelectric Transducers
                                                                  • 15101 Sensitivity
                                                                  • 15102 Piezoelectric Accelerometer
                                                                  • 15103 Charge Amplifier
                                                                      • 16 Torque Force and Other Sensors
                                                                        • 161 Strain Gage Sensors
                                                                          • 1611 Equations for Strain Gage Measurements
                                                                          • 1612 Bridge Sensitivity
                                                                          • 1613 The Bridge Constant
                                                                          • 1614 The Calibration Constant
                                                                          • 1615 Data Acquisition
                                                                          • 1616 Accuracy Considerations
                                                                          • 1617 Semiconductor Strain Gages
                                                                          • 1618 Force and Torque Sensors
                                                                          • 1619 Strain Gage Torque Sensors
                                                                          • 16110 Deflection Torque Sensors
                                                                          • 16111 Variable-Reluctance Torque Sensor
                                                                          • 16112 Reaction Torque Sensors
                                                                            • 162 Miscellaneous Sensors
                                                                              • 1621 Stroboscope
                                                                              • 1622 Fiber Optic Sensors and Lasers
                                                                              • 1623 Fiber-Optic Gyroscope
                                                                              • 1624 Laser Doppler Interferometer
                                                                              • 1625 Ultrasonic Sensors
                                                                              • 1626 Gyroscopic Sensors
                                                                                  • References
                                                                                  • Appendix 1A Virtual Instrumentation for Data Acquisition Analysis and Presentation
                                                                                    • Summary
                                                                                    • List of Abbreviations
                                                                                    • 1A1 Dynamic Signals
                                                                                      • 1A11 Acquiring and Simulating Dynamic Signals
                                                                                        • 1A111 Aliasing
                                                                                        • 1A112 Time Continuity
                                                                                            • 1A2 Measurement Configuration Considerations
                                                                                              • 1A21 Input Signal Considerations
                                                                                                • 1A211 Input Pseudodifferential and Differential Configuration
                                                                                                • 1A212 Gain
                                                                                                • 1A213 Input Coupling
                                                                                                • 1A214 Integrated Electronic Piezoelectric Excitation
                                                                                                • 1A215 Nyquist Frequency and Bandwidth
                                                                                                • 1A216 Analog-to-Digital Conversion
                                                                                                • 1A217 Antialias Filters
                                                                                                • 1A218 Input Filter Delay
                                                                                                • 1A219 Overload Detection
                                                                                                  • 1A22 Output Signal Considerations
                                                                                                    • 1A221 Output Pseudodifferential and Differential Configuration
                                                                                                    • 1A222 Attenuation
                                                                                                    • 1A223 Digital-to-Analog Conversion
                                                                                                    • 1A224 Anti-imaging and Interpolation Filters
                                                                                                    • 1A225 Output Filter Delay
                                                                                                        • 1A3 Scaling and Calibration
                                                                                                          • 1A31 Scaling to Engineering Units
                                                                                                          • 1A32 Performing System Calibration
                                                                                                            • 1A321 Propagation Delay Calibration
                                                                                                                • 1A4 Limit Testing Analysis
                                                                                                                  • 1A41 Limit Testing Overview
                                                                                                                  • 1A42 Using the SVT Limit Testing VI
                                                                                                                    • 1A5 Integration
                                                                                                                      • 1A51 Introduction to Integration
                                                                                                                      • 1A52 Implementing Integration
                                                                                                                        • 1A521 Challenges when Integrating Vibration Data
                                                                                                                          • 1A53 Time-Domain Integration
                                                                                                                            • 1A531 Single-Shot Acquisition and Integration
                                                                                                                            • 1A532 Continuous Acquisition and Integration
                                                                                                                              • 1A54 Frequency-Domain Integration
                                                                                                                                • 1A6 Vibration-Level Measurements
                                                                                                                                  • 1A61 Measuring the Root Mean Square Level
                                                                                                                                    • 1A611 Single-Shot Buffered Acquisition
                                                                                                                                    • 1A612 Continuous Signal Acquisition
                                                                                                                                      • 1A62 Performing a Running RMS Level Measurement
                                                                                                                                      • 1A63 Computing the Peak Level
                                                                                                                                      • 1A64 Computing the Crest Factor
                                                                                                                                        • 1A7 Frequency Analysis
                                                                                                                                          • 1A71 FFT Fundamentals
                                                                                                                                            • 1A711 Number of Samples
                                                                                                                                            • 1A712 Frequency Resolution
                                                                                                                                            • 1A713 Maximum Resolvable Frequency
                                                                                                                                            • 1A714 Minimum Resolvable Frequency
                                                                                                                                            • 1A715 Number of Spectral Lines
                                                                                                                                            • 1A716 Relationship between Time-Domain and Frequency-Domain Specifications and Parameters
                                                                                                                                              • 1A72 Increasing Frequency Resolution
                                                                                                                                                • 1A721 Zoom FFT Analysis
                                                                                                                                                • 1A722 Frequency Resolution of the Zoom FFT VIs
                                                                                                                                                • 1A723 Zoom Measurement
                                                                                                                                                • 1A724 Zoom Settings
                                                                                                                                                • 1A725 Subset Analysis
                                                                                                                                                    • 1A8 Transient Analysis
                                                                                                                                                      • 1A81 Transient Analysis with the Sound and Vibration Toolkit
                                                                                                                                                      • 1A82 Performing an STFT vs Time
                                                                                                                                                        • 1A821 Selecting the FFT Block Size
                                                                                                                                                        • 1A822 Overlapping
                                                                                                                                                        • 1A823 Using the SVT STFT vs Time VI
                                                                                                                                                          • 1A83 Performing an STFT vs Rotational Speed
                                                                                                                                                            • 1A831 Converting the Pulse Train to Rotational Speed
                                                                                                                                                            • 1A832 STFT vs RPM
                                                                                                                                                              • 1A84 Measuring a Shock Response Spectrum
                                                                                                                                                                • 1A9 Waterfall Display
                                                                                                                                                                  • 1A91 Using the Display VIs
                                                                                                                                                                    • 1A911 Initializing the Display
                                                                                                                                                                    • 1A912 Sending Data to the Display
                                                                                                                                                                    • 1A913 Waterfall Display for Frequency Analysis
                                                                                                                                                                    • 1A914 Waterfall Display for Transient Analysis
                                                                                                                                                                    • 1A915 Waterfall Display for Octave Spectra
                                                                                                                                                                        • 1A10 Swept-Sine Measurements
                                                                                                                                                                          • 1A101 Swept-Sine Overview
                                                                                                                                                                          • 1A102 Choosing Swept-Sine vs FFT Measurements
                                                                                                                                                                          • 1A103 Taking a Swept-Sine Measurement
                                                                                                                                                                          • 1A104 Swept-Sine Measurement Example
                                                                                                                                                                              • Bibliography
                                                                                                                                                                              • Related Titles
                                                                                                                                                                                  • 53191ch2
                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                    • Chapter 2 Signal Conditioning and Modification
                                                                                                                                                                                      • Summary
                                                                                                                                                                                      • 21 Introduction
                                                                                                                                                                                      • 22 Amplifiers
                                                                                                                                                                                        • 221 Operational Amplifier
                                                                                                                                                                                        • 222 Use of Feedback in Opamp
                                                                                                                                                                                        • 223 Voltage Current and Power Amplifiers
                                                                                                                                                                                          • 2231 Charge Amplifiers
                                                                                                                                                                                            • 224 Instrumentation Amplifiers
                                                                                                                                                                                              • 2241 Differential Amplifier
                                                                                                                                                                                              • 2242 Common Mode
                                                                                                                                                                                                • 225 Amplifier Performance Ratings
                                                                                                                                                                                                  • 2251 Common-Mode Rejection Ratio
                                                                                                                                                                                                    • 226 Component Interconnection
                                                                                                                                                                                                      • 2261 Impedance Characteristics
                                                                                                                                                                                                      • 2262 Cascade Connection of Devices
                                                                                                                                                                                                      • 2263 AC-Coupled Ampliers
                                                                                                                                                                                                          • 23 Analog Filters
                                                                                                                                                                                                            • 231 Passive Filters and Active Filters
                                                                                                                                                                                                              • 2311 Number of Poles
                                                                                                                                                                                                                • 232 Low-Pass Filters
                                                                                                                                                                                                                  • 2321 Low-Pass Butterworth Filter
                                                                                                                                                                                                                    • 233 High-Pass Filters
                                                                                                                                                                                                                    • 234 Band-Pass Filters
                                                                                                                                                                                                                      • 2341 Resonance-Type Band-Pass Filters
                                                                                                                                                                                                                        • 235 Band-Reject Filters
                                                                                                                                                                                                                          • 24 Modulators and Demodulators
                                                                                                                                                                                                                            • 241 Amplitude Modulation
                                                                                                                                                                                                                              • 2411 Modulation Theorem
                                                                                                                                                                                                                              • 2412 Side Frequencies and Side Bands
                                                                                                                                                                                                                                • 242 Application of Amplitude Modulation
                                                                                                                                                                                                                                  • 2421 Fault Detection and Diagnosis
                                                                                                                                                                                                                                    • 243 Demodulation
                                                                                                                                                                                                                                      • 25 Analog ndashDigital Conversion
                                                                                                                                                                                                                                        • 251 Digital-to-Analog Conversion
                                                                                                                                                                                                                                          • 2511 DAC Error Sources
                                                                                                                                                                                                                                            • 252 Analog-to-Digital Conversion
                                                                                                                                                                                                                                            • 253 Analog-to-Digital Converter Performance Characteristics
                                                                                                                                                                                                                                              • 2531 Resolution and Quantization Error
                                                                                                                                                                                                                                              • 2532 Monotonicity Nonlinearity and Offset Error
                                                                                                                                                                                                                                              • 2533 Analog-to-Digital Converter Conversion Rate
                                                                                                                                                                                                                                                • 254 Sample-and-Hold Circuitry
                                                                                                                                                                                                                                                • 255 Digital Filters
                                                                                                                                                                                                                                                  • 2551 Software Implementation and Hardware Implementation
                                                                                                                                                                                                                                                      • 26 Bridge Circuits
                                                                                                                                                                                                                                                        • 261 Wheatstone Bridge
                                                                                                                                                                                                                                                        • 262 Constant-Current Bridge
                                                                                                                                                                                                                                                        • 263 Bridge Amplifiers
                                                                                                                                                                                                                                                          • 2631 Half-Bridge Circuits
                                                                                                                                                                                                                                                            • 264 Impedance Bridges
                                                                                                                                                                                                                                                              • 2641 Owen Bridge
                                                                                                                                                                                                                                                              • 2642 Wien-Bridge Oscillator
                                                                                                                                                                                                                                                                  • 27 Linearizing Devices
                                                                                                                                                                                                                                                                    • 271 Linearization by Software
                                                                                                                                                                                                                                                                    • 272 Linearization by Hardware Logic
                                                                                                                                                                                                                                                                    • 273 Analog Linearizing Circuitry
                                                                                                                                                                                                                                                                    • 274 Offsetting Circuitry
                                                                                                                                                                                                                                                                    • 275 Proportional-Output Circuitry
                                                                                                                                                                                                                                                                      • 2751 Curve-Shaping Circuitry
                                                                                                                                                                                                                                                                          • 28 Miscellaneous Signal Modification Circuitry
                                                                                                                                                                                                                                                                            • 281 Phase Shifters
                                                                                                                                                                                                                                                                            • 282 Voltage-to-Frequency Converter
                                                                                                                                                                                                                                                                            • 283 Frequency-to-Voltage Converter
                                                                                                                                                                                                                                                                            • 284 Voltage-to-Current Converters
                                                                                                                                                                                                                                                                            • 285 Peak-Hold Circuits
                                                                                                                                                                                                                                                                              • 29 Signal Analyzers and Display Devices
                                                                                                                                                                                                                                                                                • 291 Signal Analyzers
                                                                                                                                                                                                                                                                                • 292 Oscilloscopes
                                                                                                                                                                                                                                                                                  • 2921 Triggering
                                                                                                                                                                                                                                                                                  • 2922 Lissajous Patterns
                                                                                                                                                                                                                                                                                  • 2923 Digital Oscilloscopes
                                                                                                                                                                                                                                                                                      • Bibliography
                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                          • 53191ch3
                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                            • Chapter 3 Vibration Testing
                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                              • 31 Introduction
                                                                                                                                                                                                                                                                                              • 32 Representation of a Vibration Environment
                                                                                                                                                                                                                                                                                                • 321 Test Signals
                                                                                                                                                                                                                                                                                                  • 3211 Stochastic vs Deterministic Signals
                                                                                                                                                                                                                                                                                                    • 322 Deterministic Signal Representation
                                                                                                                                                                                                                                                                                                      • 3221 Single-Frequency Signals
                                                                                                                                                                                                                                                                                                      • 3222 Sine Sweep
                                                                                                                                                                                                                                                                                                      • 3223 Sine Dwell
                                                                                                                                                                                                                                                                                                      • 3224 Decaying Sine
                                                                                                                                                                                                                                                                                                      • 3225 Sine Beat
                                                                                                                                                                                                                                                                                                      • 3226 Sine Beat with Pauses
                                                                                                                                                                                                                                                                                                      • 3227 Multifrequency Signals
                                                                                                                                                                                                                                                                                                      • 3228 Actual Excitation Records
                                                                                                                                                                                                                                                                                                      • 3229 Simulated Excitation Signals
                                                                                                                                                                                                                                                                                                        • 323 Stochastic Signal Representation
                                                                                                                                                                                                                                                                                                          • 3231 Ergodic Random Signals
                                                                                                                                                                                                                                                                                                          • 3232 Stationary Random Signals
                                                                                                                                                                                                                                                                                                          • 3233 Independent and Uncorrelated Signals
                                                                                                                                                                                                                                                                                                          • 3234 Transmission of Random Excitations
                                                                                                                                                                                                                                                                                                            • 324 Frequency-Domain Representations
                                                                                                                                                                                                                                                                                                              • 3241 Fourier Spectrum Method
                                                                                                                                                                                                                                                                                                              • 3242 Power Spectral Density Method
                                                                                                                                                                                                                                                                                                                • 325 Response Spectrum
                                                                                                                                                                                                                                                                                                                  • 3251 Displacement Velocity and Acceleration Spectra
                                                                                                                                                                                                                                                                                                                  • 3252 Response-Spectra Plotting Paper
                                                                                                                                                                                                                                                                                                                  • 3253 Zero-Period Acceleration
                                                                                                                                                                                                                                                                                                                  • 3254 Uses of Response Spectra
                                                                                                                                                                                                                                                                                                                    • 326 Comparison of Various Representations
                                                                                                                                                                                                                                                                                                                      • 33 Pretest Procedures
                                                                                                                                                                                                                                                                                                                        • 331 Purpose of Testing
                                                                                                                                                                                                                                                                                                                        • 332 Service Functions
                                                                                                                                                                                                                                                                                                                          • 3321 Active Equipment
                                                                                                                                                                                                                                                                                                                          • 3322 Passive Equipment
                                                                                                                                                                                                                                                                                                                          • 3323 Functional Testing
                                                                                                                                                                                                                                                                                                                            • 333 Information Acquisition
                                                                                                                                                                                                                                                                                                                              • 3331 Interface Details
                                                                                                                                                                                                                                                                                                                              • 3332 Effect of Neglecting Interface Dynamics
                                                                                                                                                                                                                                                                                                                              • 3333 Effects of Damping
                                                                                                                                                                                                                                                                                                                              • 3334 Effects of Inertia
                                                                                                                                                                                                                                                                                                                              • 3335 Effect of Natural Frequency
                                                                                                                                                                                                                                                                                                                              • 3336 Effect of Excitation Frequency
                                                                                                                                                                                                                                                                                                                              • 3337 Other Effects of Interface
                                                                                                                                                                                                                                                                                                                                • 334 Test-Program Planning
                                                                                                                                                                                                                                                                                                                                  • 3341 Testing of Cabinet-Mounted Equipment
                                                                                                                                                                                                                                                                                                                                    • 335 Pretest Inspection
                                                                                                                                                                                                                                                                                                                                      • 34 Testing Procedures
                                                                                                                                                                                                                                                                                                                                        • 341 Resonance Search
                                                                                                                                                                                                                                                                                                                                        • 342 Methods of Determining Frequency-Response Functions
                                                                                                                                                                                                                                                                                                                                          • 3421 Fourier Transform Method
                                                                                                                                                                                                                                                                                                                                          • 3422 Spectral Density Method
                                                                                                                                                                                                                                                                                                                                          • 3423 Harmonic Excitation Method
                                                                                                                                                                                                                                                                                                                                            • 343 Resonance-Search Test Methods
                                                                                                                                                                                                                                                                                                                                              • 3431 Hammer (Bump) Test and Drop Test
                                                                                                                                                                                                                                                                                                                                              • 3432 Pluck Test
                                                                                                                                                                                                                                                                                                                                              • 3433 Shaker Tests
                                                                                                                                                                                                                                                                                                                                                • 344 Mechanical Aging
                                                                                                                                                                                                                                                                                                                                                  • 3441 Equivalence for Mechanical Aging
                                                                                                                                                                                                                                                                                                                                                  • 3442 Excitation-Intensity Equivalence
                                                                                                                                                                                                                                                                                                                                                  • 3443 Dynamic-Excitation Equivalence
                                                                                                                                                                                                                                                                                                                                                  • 3444 Cumulative Damage Theory
                                                                                                                                                                                                                                                                                                                                                    • 345 Test-Response Spectrum Generation
                                                                                                                                                                                                                                                                                                                                                    • 346 Instrument Calibration
                                                                                                                                                                                                                                                                                                                                                    • 347 Test-Object Mounting
                                                                                                                                                                                                                                                                                                                                                    • 348 Test-Input Considerations
                                                                                                                                                                                                                                                                                                                                                      • 3481 Test Nomenclature
                                                                                                                                                                                                                                                                                                                                                      • 3482 Testing with Uncorrelated Excitations
                                                                                                                                                                                                                                                                                                                                                      • 3483 Symmetrical Rectilinear Testing
                                                                                                                                                                                                                                                                                                                                                      • 3484 Geometry vs Dynamics
                                                                                                                                                                                                                                                                                                                                                      • 3485 Some Limitations
                                                                                                                                                                                                                                                                                                                                                      • 3486 Testing Black Boxes
                                                                                                                                                                                                                                                                                                                                                      • 3487 Phasing of Excitations
                                                                                                                                                                                                                                                                                                                                                      • 3488 Testing a Gray or White Box
                                                                                                                                                                                                                                                                                                                                                      • 3489 Overtesting in Multitest Sequences
                                                                                                                                                                                                                                                                                                                                                          • 35 Some Practical Information
                                                                                                                                                                                                                                                                                                                                                            • 351 Random Vibration Test Example
                                                                                                                                                                                                                                                                                                                                                            • 352 Vibration Shakers and Control Systems
                                                                                                                                                                                                                                                                                                                                                              • Bibliography
                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                  • 53191ch4
                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                    • Chapter 4 Experimental Modal Analysis
                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                      • 41 Introduction
                                                                                                                                                                                                                                                                                                                                                                      • 42 Frequency-Domain Formulation
                                                                                                                                                                                                                                                                                                                                                                        • 421 Transfer-Function Matrix
                                                                                                                                                                                                                                                                                                                                                                        • 422 Principle of Reciprocity
                                                                                                                                                                                                                                                                                                                                                                          • 43 Experimental Model Development
                                                                                                                                                                                                                                                                                                                                                                            • 431 Extraction of the Time-Domain Model
                                                                                                                                                                                                                                                                                                                                                                              • 44 Curve Fitting of Transfer Functions
                                                                                                                                                                                                                                                                                                                                                                                • 441 Problem Identification
                                                                                                                                                                                                                                                                                                                                                                                • 442 Single- and Multi-Degree-of-Freedom Techniques
                                                                                                                                                                                                                                                                                                                                                                                • 443 Single-Degree-of-Freedom Parameter Extraction in the Frequency Domain
                                                                                                                                                                                                                                                                                                                                                                                  • 4431 Circle-Fit Method
                                                                                                                                                                                                                                                                                                                                                                                    • Case of Viscous Damping
                                                                                                                                                                                                                                                                                                                                                                                    • Case of Hysteretic Damping
                                                                                                                                                                                                                                                                                                                                                                                      • 4432 Peak-Picking Method
                                                                                                                                                                                                                                                                                                                                                                                        • 444 Multi-Degree of Freedom Curve Fitting
                                                                                                                                                                                                                                                                                                                                                                                          • 4441 Formulation of the Method
                                                                                                                                                                                                                                                                                                                                                                                            • 445 A Comment on Static Modes and Rigid-Body Modes
                                                                                                                                                                                                                                                                                                                                                                                            • 446 Residue Extraction
                                                                                                                                                                                                                                                                                                                                                                                              • 45 Laboratory Experiments
                                                                                                                                                                                                                                                                                                                                                                                                • 451 Lumped-Parameter System
                                                                                                                                                                                                                                                                                                                                                                                                  • 4511 Frequency-Domain Test
                                                                                                                                                                                                                                                                                                                                                                                                  • 4512 Time-Domain Tests
                                                                                                                                                                                                                                                                                                                                                                                                    • 452 Distributed-Parameter System
                                                                                                                                                                                                                                                                                                                                                                                                      • 46 Commercial EMA Systems
                                                                                                                                                                                                                                                                                                                                                                                                        • 461 System Configuration
                                                                                                                                                                                                                                                                                                                                                                                                          • 4611 FFT Analysis Options
                                                                                                                                                                                                                                                                                                                                                                                                          • 4612 Modal Analysis Components
                                                                                                                                                                                                                                                                                                                                                                                                              • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                  • 53191ch5
                                                                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                    • Chapter 5 Mechanical Shock
                                                                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                      • 51 Definitions
                                                                                                                                                                                                                                                                                                                                                                                                                        • 511 Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 512 Simple (or Perfect) Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 513 Half-Sine Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 514 Versed-Sine (or Haversine) Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 515 Terminal Peak Sawtooth Shock or Final Peak Sawtooth Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 516 Rectangular Shock
                                                                                                                                                                                                                                                                                                                                                                                                                          • 5161 Trapezoidal Shock
                                                                                                                                                                                                                                                                                                                                                                                                                              • 52 Description in the Time Domain
                                                                                                                                                                                                                                                                                                                                                                                                                              • 53 Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                • 531 Need
                                                                                                                                                                                                                                                                                                                                                                                                                                • 532 Shock Response Spectrum Definition
                                                                                                                                                                                                                                                                                                                                                                                                                                • 533 Response of a Linear One-Degree-of-Freedom System
                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5331 Shock Defined by a Force
                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5332 Shock Defined by an Acceleration
                                                                                                                                                                                                                                                                                                                                                                                                                                    • 534 Definitions
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5341 Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5342 Absolute Acceleration Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5343 Relative Displacement Shock Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5344 Primary Positive Shock Response Spectrum or Initial Positive Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5345 Primary (or Initial) Negative Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5346 Secondary (or Residual) Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5347 Positive (or Maximum Positive) Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5348 Negative (or Maximum Negative) Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5349 Maximax Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53410 Choice of Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                        • 535 Standardized Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5351 Definition
                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5352 Standardized Shock Response Spectra of Simple Shocks
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53521 Half-Sine Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53522 Versed Sine Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53523 Terminal Peak Sawtooth Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53524 Rectangular Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53525 Trapezoidal Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 536 Choice of Damping
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 537 Shock Response Spectra Domains
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 538 Algorithms for Calculation of the Shock Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 539 Choice of the Digitization Frequency of the Signal
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5310 Use of Shock Response Spectra for the Study of Systems with Several Degrees of Freedom
                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 54 Pyroshocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 55 Use of Shock Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 551 Severity Comparison of Several Shocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 552 Test Specification Development from Real Environment Data
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5521 Synthesis of Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5522 Nature of the Specification
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5523 Choice of Shape
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5524 Amplitude
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5525 Duration
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5526 Difficulties
                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 56 Standards
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 561 Types of Standards
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 562 Installation Conditions of Test Item
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 563 Uncertainty Factor
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 564 Bump Test
                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 57 Damage Boundary Curve
                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 571 Definition
                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 572 Analysis of Test Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 58 Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 581 Main Types
                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 582 Impact Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5821 Universal Shock-Test Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 58211 Impact Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 58212 Impulse Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 583 Shock Simulators (Programmers)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5831 Half-Sine Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58311 Shock Duration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58312 Impact Velocity
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58313 Maximum Deformation of the Shock Simulator (Programmer)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58314 Shock Amplitude
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58315 Characteristics of the Target
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5832 Terminal Peak Sawtooth Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5833 Rectangular Pulse ndash Trapezoidal Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5834 Universal Shock Simulator (Programmer)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 58341 Generating a Half-Sine Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 58342 Generating a Terminal Peak Sawtooth Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 58343 Trapezoidal Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 584 Limitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5841 Limitations of the Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5842 Limitations of Shock Simulators
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 585 Pneumatic Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 586 High Impact Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5861 Lightweight High Impact Shock Machine
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5862 Medium Weight High Impact Shock Machine
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 587 Specific Test Facilities
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 59 Generation of Shock Using Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 591 Principle Behind the Generation of a Simple Shape Signal versus Time
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 592 Main Advantages
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 593 Pre- and Postshocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5931 Requirements
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5932 Solutions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 59321 Optimized Pre- and Postpulses
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5933 Incidence on the Shock Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 594 Limitations of Electrodynamic Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5941 Mechanical Limitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 59411 Abacuses
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5942 Electronic Limitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 595 The Use of Electrohydraulic Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 510 Control by a Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 5101 Principle
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 5102 Principal Shapes of Elementary Signals
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 51021 Decaying Sinusoid
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 51022 ZERD Function
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 51023 WAVSIN Waveform
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 5103 Comparison of WAVSIN SHOC Waveforms and Decaying Sinusoid
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 5104 Criticism of Control by a Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 511 Pyrotechnic Shock Simulation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5111 Simulation Using Pyrotechnic Facilities
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5112 Simulation Using Metal-to-Metal Impact
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5113 Simulation Using Electrodynamic Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5114 Simulation Using Conventional Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53191ch6
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Chapter 6 Machine Condition Monitoring and Fault Diagnostics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 61 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 62 Machinery Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 621 Causes of Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 622 Types of Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 623 Frequency of Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 63 Basic Maintenance Strategies
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 631 Run-to-Failure (Breakdown) Maintenance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 632 Scheduled (Preventative) Maintenance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 633 Condition-Based (Predictive Proactive Reliability Centered On-Condition) Maintenance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 64 Factors Which Influence Maintenance Strategy
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 65 Machine Condition Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 651 Periodic Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 652 Continuous Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 66 Transducer Selection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 661 Noncontact Displacement Transducers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 662 Velocity Transducers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 663 Acceleration Transducers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 67 Transducer Location
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 68 Recording and Analysis Instrumentation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 681 Vibration Meters
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 682 Data Collectors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 683 Frequency-Domain Analyzers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 684 Time-Domain Instruments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 685 Tracking Analyzers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 69 Display Formats and Analysis Tools
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 691 Time Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6911 Time-Waveform Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6912 Time-Waveform Indices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6913 Time-Synchronous Averaging
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6914 Negative Averaging
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6915 Orbits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6916 Probability Density Functions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6917 Probability Density Moments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 692 Frequency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6921 Band-Pass Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6922 Shock Pulse (Spike Energy)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6923 Enveloped Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6924 Signature Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6925 Cascades (Waterfall Plots)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6926 Masks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6927 Frequency-Domain Indices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 693 Modal Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 694 Quefrency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 610 Fault Detection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 6101 Standards
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61011 Standards Based on Machinery Type
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61012 Standards Based on Vibration Severity
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 6102 Acceptance Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 61021 Statistical Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 6103 Frequency-Domain Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61031 Limited Band Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61032 Constant Bandwidth Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61033 Constant Percentage Bandwidth Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 611 Fault Diagnostics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 6111 Forcing Functions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61111 Unbalance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61112 Misalignment
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61113 Mechanical Looseness
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61114 Soft Foot
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61115 Rubs
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61116 Resonances
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61117 Oil Whirl
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61118 Oil Whip
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61119 Structural Vibrations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 611110 Foundation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 6112 Specific Machine Components
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 61121 Damaged or Worn Rolling-Element Bearings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 61122 Damaged or Worn Gears
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 6113 Specific Machine Types
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61131 Pumps
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61132 Fans
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61133 Electric Motors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61134 Steam and Gas Turbines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61135 Compressors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61136 Reciprocating Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 6114 Advanced Fault Diagnostic Techniques
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 53191ch7
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • Chapter 7 Vibration-Based Tool Condition Monitoring Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 71 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 72 Mechanics of Turning
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 721 General Terms
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 722 Chatter Vibrations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 723 Tool Wear
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7231 Tool Failure Mechanisms
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7232 Tool Failure Modes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7233 Tool Wear Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7234 Tool Wear Stages
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 73 Vibration Signal Recording
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 731 Direct and Indirect Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 732 Sensor Requirements for Tool Wear Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 733 Force Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7331 Direct Measurement Dynamometers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7332 Indirect Force Sensors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7333 Piezoelectric Strain Sensors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7334 Resistance Strain Gauges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7335 Customized Force Sensors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 734 Acceleration Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 735 Acoustic Emission Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 736 Sensor Comparisons
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 74 Signal Processing for Sensor-Based Tool Condition Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 741 Feature Extraction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7411 Time Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7412 Frequency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7413 Statistical Processing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7414 TimendashFrequency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 742 Feature Selection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 75 Wear ModelDecision-Making for Sensor-Based Tool Condition Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 751 Trending Threshold
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 752 Neural Networks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7521 Unsupervised Networks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7522 Supervised Networks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 753 Fuzzy Logic
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 754 Other Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 76 Conclusion
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53191ch8
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Chapter 8 Fault Diagnosis of Helicopter Gearboxes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 81 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 82 Abnormality Scaling
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 83 The Structure-Based Connectionist Network
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 84 Sensor Location Selection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 841 Coverage Index
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 842 Overlap Index
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 843 Monitoring Effectiveness
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 85 A Case Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 851 Structural and Featural Influences
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 852 Evaluation of Influences
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 853 Fault Detection Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 854 Fault Diagnostic Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 8541 Faulty Subsystem Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 8542 Faulty Component Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 855 Sensor Location Evaluation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 856 Sensor Location Validation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 86 Conclusion
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 53191ch9
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Chapter 9 Vibration Suppression and Monitoring in Precision Motion Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 91 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 92 Mechanical Design to Minimize Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 921 Stability and Static Determinacy of Machine Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 922 Two-Dimensional Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 923 Three-Dimensional Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 93 Adaptive Notch Filter
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 931 Fast Fourier Transform
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 932 Simulation and Experiments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 94 Real-Time Vibration Analyzer
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 941 Learning Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 942 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 943 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 944 Experiments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 9441 Input Variables mdash the Evaluation Criteria
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 94411 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 94412 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 9442 Evaluation Rules
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 94421 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 94422 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 9443 Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 94431 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 94432 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 95 Practical Insights and Case Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 96 Conclusions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 53191ch10
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Chapter 10 Vibration and Shock Problems of Civil Engineering Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 101 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 102 Earthquake-Induced Vibration of Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1021 Seismicity and Ground Motions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1022 Influence of Local Site Conditions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1023 Response of Structures to Ground Motions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1024 Dynamic Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10241 Equations of Motion for Linear Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10242 Equations of Motion for Linear Multiple-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1025 Earthquake Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10251 Elastic Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10252 Smoothed Design Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10253 Ductility-Modified Response Spectrum Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1026 Design Philosophy and the Code Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10261 Performance-Based Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1027 Analysis Options for Earthquake Effects
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10271 Dynamic Time History Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10272 Response Spectrum Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 102721 Response Spectrum Analysis of Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 102722 Response Spectrum Analysis of Multi-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10273 Equivalent Static Analysis (Force-Based Approach)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10274 Displacement-Based Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1028 SoilndashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1029 Active and Passive Control Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 10210 Worked Examples
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 103 Dynamic Effects of Wind Loading on Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1031 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1032 Wind Speed
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1033 Design Structures for Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10331 Types of Wind Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10332 Design Criteria
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10333 Static Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1034 Along and Across-Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10341 Along-Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10342 Across-Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1035 Wind Tunnel Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1036 Comfort Criteria Human Response to Building Motion
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1037 Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1038 Comparison with Earthquake Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 104 Vibrations Due to Fluid ndashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1041 Added Mass and Inertial Coupling
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1042 Wave-Induced Vibration of Structure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 105 Blast Loading and Blast Effects on Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1051 Explosions and Blast Phenomenon
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1052 Explosive Air-Blast Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10521 Blast Wave Scaling Laws
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10522 Prediction of Blast Pressure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1053 Gas Explosion Loading and Effect of Internal Explosions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1054 Structural Response to Blast Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10541 Elastic Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10542 Elasto-Plastic Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1055 Material Behaviors at High Strain Rate
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10551 Dynamic Properties of Concrete under High Strain Rates
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10552 Dynamic Properties of Reinforcing Steel under High Strain Rates
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1056 Failure Modes of Blast-Loaded Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10561 Global Structural Behavior
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10562 Localized Structural Behavior
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10563 PressurendashImpulse ( PndashI ) Diagrams
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1057 Blast WavendashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1058 Effect of Ground Shocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10581 Loads from Air-Induced Ground Shock
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10582 Loads from Direct Ground Shock
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1059 Technical Design Manuals for Blast-Resistant Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 10510 Computer Programs for Blast and Shock Effects
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 106 Impact Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1061 Structural Impact between Two Bodies mdash Hard Impact and Soft Impact
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1062 Example mdash Aircraft Impact
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 107 Floor Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1071 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1072 Types of Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10721 Walking
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10722 Rhythmic Activities
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10723 Mechanical Equipment
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10724 Analysis Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1073 Natural Frequency of Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10731 Computing the Natural Frequency
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10732 Computing Deflection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10733 Damping
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10734 Resonance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1074 Vibration Caused by Walking
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10741 Minimum Natural Frequency
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1075 Design for Rhythmic Excitation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10751 Harmonics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10752 Minimum Natural Frequency
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1076 Example mdash Vibration Analysis of a Reinforced Concrete Floor
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 53191ch11
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Chapter 11 Seismic Base Isolation and Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 111 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1111 From Ductility Design to Base Isolation and Control Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1112 The Importance of Reducing Seismic Input and Response
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 112 Seismic Base Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1121 Historical Development of Base Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1122 Basic Principle
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1123 Issues in Seismic Base Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11231 Performance Criteria
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11232 Type of Structure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11233 Site Characteristics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11234 Retrofit Issues
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11235 Design of Building Services
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11236 Expected Life of Isolator
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1124 Seismic Isolation Devices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11241 Laminated Rubber Bearings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11242 Lead Rubber Bearing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11243 Friction-Based Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11244 Other Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1125 Design of Isolation Devices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11251 High-Damping Rubber Bearing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112511 Stability against Buckling
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112512 Stability against Roll Out
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11252 Lead Rubber Bearings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112521 Design of Lead Plug
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112522 Design of Laminated Rubber Bearing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11253 Design of Friction Pendulum System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1126 Verification of Properties of Isolation Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11261 Tests for Isolation Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 112611 System Characterization Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 112612 Prototype Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 112613 Quality Control Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11262 Uniform Building Code Recommendations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112621 Units Dependent on Loading Rates
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112622 Units Dependent on Bilateral Load
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112623 System Adequacy
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1127 Analysis of Base-Isolated Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11271 Modeling of a Superstructure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11272 Modeling of Isolation System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11273 Static Analysis Procedure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11274 Dynamic Analysis Procedure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 112741 Response Spectrum Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 112742 Time-History Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11275 Software for Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1128 Experimental Methods for Isolated Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1129 Implementation of Seismic Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11291 New Construction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112911 Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112912 Bridges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11292 Seismic Retrofit
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112921 Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112922 Bridges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11293 Other Implementations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 11210 Performance during Past Earthquakes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 112101 Performance of Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 112102 Performance of Bridges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 113 Seismic Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1131 Historical Development of Seismic Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1132 Basic Principles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11321 Passive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11322 Active Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11323 Semiactive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11324 Hybrid Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11325 Categorization of Basic Principles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1133 Important Issues in Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11331 SoilndashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11332 DevicendashStructure Interaction and Time Delay
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11333 Design Guidelines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1134 Vibration-Control Devices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11341 Passive Control Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113411 Metallic Yielding Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113412 Friction Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113413 Viscoelastic Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113414 Viscous Fluid Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113415 Tuned Mass Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11342 Active Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113421 Electromagnetic Actuator
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113422 Hydraulic Actuators
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11343 Semiactive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113431 Variable-Orifice Hydraulic Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113432 Controllable Fluid Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113433 Controllable Friction Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11344 Hybrid Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1135 Control Algorithm
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11351 Active Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11352 Semiactive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113521 Common Control Schemes for Controllable Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113522 Special Control Schemes for Controllable Damper
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1136 Experimental Performance Verification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11361 Shaking Table Tests of a Flexible Structural Model with TMD AMD and ATMD
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11362 Substructure Hybrid Test
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113621 Hybrid Tests Using Hydraulic Actuator
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113622 Hybrid Tests Using Shaking Table
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113623 Hybrid Tests Using Inertia-Force-Driven Loading System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1137 Implementations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11371 Semiactive Control of Full-Scale Structures Using Variable Joint Damper System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113711 Background of Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113712 Test System Set Up
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113713 Control Algorithm
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113714 Test Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11372 Application of Structural Control Technologies to Seismic Retrofit of a Cable-Stayed Bridge
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113721 Background of Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113722 Basic Concept of Seismic Retrofit
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113723 Modal Shape Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113724 Time-History Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113725 Soil ndash Structure Interaction Effect
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113726 Semiactive Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53191ch12
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Chapter 12 Seismic Random Vibration of Long-Span Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 121 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1211 Basic Concepts of Random Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12111 Stationary Random Process
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12112 Nonstationary Random Process
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1212 Three Methods for Structural Seismic Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12121 Response Spectrum Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12122 Time-History Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12123 Random Vibration Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 121231 Davenport Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 121232 Vanmarcke Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 12124 Comparisons of the Three Seismic-Analysis Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 122 Seismic Random-Excitation Fields
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1221 Power Spectral Density of Spatially Varying Ground Acceleration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1222 Several Coherence Models
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12221 FengndashHu Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12222 Harichandran ndashVanmarcke Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12223 LohndashYeh Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12224 OliveirandashHaondashPenzien Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12225 LucondashWong Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12226 QundashWangndashWang Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1223 Generation of Ground Acceleration Power Spectral Density Curves from Acceleration Response Spectrum Curves
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12231 Kaul Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12232 Iteration Scheme
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1224 Seismic Equations of Motion of Long-Span Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1225 Seismic Waves and Their Geometrical Expressions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 123 Pseudoexcitation Method for Structural Random Vibration Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1231 Structures Subjected to Stationary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12311 Single Stationary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12312 Multiple Stationary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1232 Structures Subjected to Nonstationary Random Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12321 Structures Subjected to Uniformly Modulated Evolutionary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 123211 Single Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 123212 Multiple Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12322 Structures Subjected to Nonuniformly Modulated Evolutionary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 123221 Single Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 123222 Multiple Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1233 Precise Integration Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12331 Precise Integration of Exponential Matrices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12332 Particular Solutions and Precise Integration Formulas for Various Forms of Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 123321 Linear Loading Form (HPD-L Form)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 123322 Sinusoidal Loading Form (HPD-S Form)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 123323 Exponentially Decaying Sinusoidal Loading Form (HPD-E Form)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 124 Long-Span Structures Subjected to Stationary Random Ground Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1241 The Solution of Equations of Motion Using the Pseudoexcitation Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1242 Numerical Comparisons with Other Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12421 Song-Hua-Jiang Suspension Bridge
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 124211 All Supports Move Uniformly
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 124212 Wave Passage Effect Is Taken into Account
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 124213 Wave-Passage Effect and Incoherence Effect Are Jointly Taken into Account
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 12422 San Joaquin Concrete Bridge
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 125 Long-Span Structures Subjected to Nonstationary Random Ground Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1251 Modulation Functions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1252 The Formulas for Nonstationary Multiexcitation Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1253 Expected Extreme Values of Nonstationary Random Processes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1254 Numerical Comparisons with the Corresponding Stationary Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 126 Conclusions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 53191ch13
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Chapter 13 Seismic Qualification of Equipment
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 131 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 132 Distribution Qualification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1321 Drive-Signal Generation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1322 Distribution Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1323 Test Procedures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 133 Seismic Qualification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1331 Stages of Seismic Qualification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1332 Test Preliminaries
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1333 Single-Frequency Testing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1334 Multifrequency Testing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1335 Generation of RRS Specifications
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 53191ch14
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                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Chapter 14 Human Response to Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 141 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 142 Vibration Excitations on Humans
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1421 Excitation Characteristics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 143 Human Response to Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1431 Vibration Perception
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1432 Frequency Weighting Curve
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1433 Iso-Perception Curves
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1434 Detection Threshold Curve
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 144 Regulation of Human Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1441 Acceptable Vibration Levels in Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1442 Whole-Body Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1443 HandndashArm Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
Page 10: Vibration Monitoring, Testing, and Instrumentationpreview.kingborn.net › 646000 › d1a74678d91943e5ba1d5e... · The MEMS Handbook, Second Edition MEMS: Introduction and Fundamentals

Contents

1 Vibration Instrumentation Clarence W de Silva 1-1

11 Introduction 1-1

12 Vibration Exciters 1-3

13 Control System 1-15

14 Performance Specification 1-21

15 Motion Sensors and Transducers 1-27

16 Torque Force and Other Sensors 1-50

Appendix 1A Virtual Instrumentation for Data Acquisition Analysis

and Presentation 1-73

2 Signal Conditioning and Modification Clarence W de Silva 2-1

21 Introduction 2-2

22 Amplifiers 2-2

23 Analog Filters 2-15

24 Modulators and Demodulators 2-29

25 AnalogndashDigital Conversion 2-37

26 Bridge Circuits 2-43

27 Linearizing Devices 2-49

28 Miscellaneous Signal Modification Circuitry 2-56

29 Signal Analyzers and Display Devices 2-62

3 Vibration Testing Clarence W de Silva 3-1

31 Introduction 3-1

32 Representation of a Vibration Environment 3-3

33 Pretest Procedures 3-24

34 Testing Procedures 3-37

35 Some Practical Information 3-52

4 Experimental Modal Analysis Clarence W de Silva 4-1

41 Introduction 4-1

42 Frequency-Domain Formulation 4-2

43 Experimental Model Development 4-8

44 Curve Fitting of Transfer Functions 4-10

45 Laboratory Experiments 4-18

46 Commercial EMA Systems 4-24

xiii

53191mdash1432007mdash1850mdashVELUmdash246493mdash CRC ndash pp 1ndash15

copy 2007 by Taylor amp Francis Group LLC

5 Mechanical Shock Christian Lalanne 5-1

51 Definitions 5-2

52 Description in the Time Domain 5-3

53 Shock Response Spectrum 5-4

54 Pyroshocks 5-17

55 Use of Shock Response Spectra 5-18

56 Standards 5-24

57 Damage Boundary Curve 5-26

58 Shock Machines 5-28

59 Generation of Shock Using Shakers 5-44

510 Control by a Shock Response Spectrum 5-52

511 Pyrotechnic Shock Simulation 5-58

6 Machine Condition Monitoring and Fault Diagnostics Chris K Mechefske 6-1

61 Introduction 6-2

62 Machinery Failure 6-2

63 Basic Maintenance Strategies 6-4

64 Factors Which Influence Maintenance Strategy 6-7

65 Machine Condition Monitoring 6-8

66 Transducer Selection 6-10

67 Transducer Location 6-14

68 Recording and Analysis Instrumentation 6-14

69 Display Formats and Analysis Tools 6-16

610 Fault Detection 6-21

611 Fault Diagnostics 6-25

7 Vibration-Based Tool Condition Monitoring Systems C Scheffer and PS Heyns 7-1

71 Introduction 7-1

72 Mechanics of Turning 7-2

73 Vibration Signal Recording 7-7

74 Signal Processing for Sensor-Based Tool Condition Monitoring 7-11

75 Wear ModelDecision-Making for Sensor-Based Tool Condition Monitoring 7-15

76 Conclusion 7-20

8 Fault Diagnosis of Helicopter Gearboxes Kourosh Danai 8-1

81 Introduction 8-1

82 Abnormality Scaling 8-5

83 The Structure-Based Connectionist Network 8-8

84 Sensor Location Selection 8-11

85 A Case Study 8-14

86 Conclusion 8-23

9 Vibration Suppression and Monitoring in Precision Motion Systems KK Tan

TH Lee KZ Tang S Huang SY Lim W Lin and YP Leow 9-1

91 Introduction 9-1

92 Mechanical Design to Minimize Vibration 9-2

93 Adaptive Notch Filter 9-10

94 Real-Time Vibration Analyzer 9-17

Contentsxiv

53191mdash1432007mdash1850mdashVELUmdash246493mdash CRC ndash pp 1ndash15

copy 2007 by Taylor amp Francis Group LLC

95 Practical Insights and Case Study 9-29

96 Conclusions 9-35

10 Vibration and Shock Problems of Civil Engineering Structures Priyan Mendis

and Tuan Ngo 10-1

101 Introduction 10-2

102 Earthquake-Induced Vibration of Structures 10-3

103 Dynamic Effects of Wind Loading on Structures 10-22

104 Vibrations Due to FluidndashStructure Interaction 10-33

105 Blast Loading and Blast Effects on Structures 10-34

106 Impact Loading 10-47

107 Floor Vibration 10-51

11 Seismic Base Isolation and Vibration Control Hirokazu Iemura Sarvesh Kumar Jain

and Mulyo Harris Pradono 11-1

111 Introduction 11-1

112 Seismic Base Isolation 11-4

113 Seismic Vibration Control 11-33

12 Seismic Random Vibration of Long-Span Structures Jiahao Lin and Yahui Zhang 12-1

121 Introduction 12-2

122 Seismic Random-Excitation Fields 12-11

123 Pseudoexcitation Method for Structural Random Vibration Analysis 12-16

124 Long-Span Structures Subjected to Stationary Random Ground Excitations 12-27

125 Long-Span Structures Subjected to Nonstationary Random Ground Excitations 12-34

126 Conclusions 12-39

13 Seismic Qualification of Equipment Clarence W de Silva 13-1

131 Introduction 13-1

132 Distribution Qualification 13-1

133 Seismic Qualification 13-6

14 Human Response to Vibration Clarence W de Silva 14-1

141 Introduction 14-1

142 Vibration Excitations on Humans 14-2

143 Human Response to Vibration 14-3

144 Regulation of Human Vibration 14-6

Contents xv

53191mdash1432007mdash1850mdashVELUmdash246493mdash CRC ndash pp 1ndash15

copy 2007 by Taylor amp Francis Group LLC

1Vibration

Instrumentation

Clarence W de SilvaThe University of British Columbia

11 Introduction 1-1

12 Vibration Exciters 1-3Shaker Selection dagger Dynamics of Electromagnetic Shakers

13 Control System 1-15Components of a Shaker Controller dagger Signal-Generating

Equipment

14 Performance Specification 1-21Parameters for Performance Specification dagger Linearity dagger

Instrument Ratings dagger Accuracy and Precision

15 Motion Sensors and Transducers 1-27Potentiometer dagger Variable-Inductance Transducers dagger

Mutual-Induction Proximity Sensor dagger Selfinduction

Transducers dagger Permanent-Magnet Transducers dagger

Alternating Current Permanent-Magnet Tachometer dagger

Alternating Current Induction Tachometer dagger Eddy Current

Transducers dagger Variable-Capacitance Transducers dagger

Piezoelectric Transducers

16 Torque Force and Other Sensors 1-50Strain Gage Sensors dagger Miscellaneous Sensors

Appendix 1A Virtual Instrumentation for DataAcquisition Analysis and Presentation 1-73

Summary

Devices useful in instrumenting a mechanical vibrating system are presented in this chapter Shakers whichgenerate vibration excitations are discussed and compared A variety of sensors including motion sensorsproximity sensors forcetorque sensors and other miscellaneous sensors are considered Performance specificationin the time domain and the frequency domain is addressed Rating parameters of instruments are given

11 Introduction

Measurement and associated experimental techniques play a significant role in the practice of vibration

Academic exposure to vibration instrumentation usually arises in laboratories in the context of learning

training and research In vibration practice perhaps the most important task of instrumentation is the

measurement or sensing of vibration Vibration sensing is useful in the following applications

1 Design and development of a product

2 Testing (screening) of a finished product for quality assurance

3 Qualification of a good-quality product to determine its suitability for a specific application

1-1

53191mdash522007mdash1201mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

4 Mechanical aging of a product prior to carrying out a test program

5 Exploratory testing of a product to determine its dynamic characteristics such as resonances

mode shapes and even a complete dynamic model

6 Vibration monitoring for performance evaluation

7 Control and suppression of vibration

Figure 11 indicates a procedure typical of experimental vibration highlighting the essential

instrumentation Vibrations are generated in a device the test object in response to some excitation In

some experimental procedures primarily in vibration testing (see Figure 11) the excitation signal has

to be generated in a signal generator in accordance with some requirement (specification) and applied to

the object through an exciter after amplification and conditioning In some other situations primarily in

performance monitoring and vibration control the excitations are generated as an integral part of the

operating environment of the vibrating object and may originate either within the object (eg engine

excitations in an automobile) or in the environment with which the object interacts during operation

(eg road disturbances on an automobile) Sensors are needed to measure vibrations in the test object In

particular a control sensor is used to check whether the specified excitation is applied to the object

and one or more response sensors may be used to measure the resulting vibrations at key locations of

the object

The sensor signals have to be properly conditioned for example by filtering and amplification and

modified for example through modulation demodulation and analog-to-digital conversion prior to

recording analyzing and display The purpose of the controller is to guarantee that the excitation is

correctly applied to the test object If the signal from the control sensor deviates from the required

excitation the controller modifies the signal to the exciter so as to reduce this deviation Furthermore the

controller will stabilize or limit (compress) the vibrations in the object It follows that instruments in

experimental vibration may be generally classified into the following categories

1 Signal-generating devices

2 Vibration exciters

3 Sensors and transducers

4 Signal conditioningmodifying devices

5 Signal analysis devices

6 Control devices

7 Vibration recording and display devices

AnalogDigital

Interface

DigitalSignal

RecorderAnalyzerDisplay

FilterAmplifier

FilterAmplifier

SignalGenerator

and ExciterController

Reference (Required)Signal (Specification)

PowerAmplifier

MountingFixtures

TestObject

ResponseSensor

ControlSensor

Exciter

SwivelBase

FIGURE 11 Typical instrumentation in experimental vibration

Vibration Monitoring Testing and Instrumentation1-2

53191mdash522007mdash1201mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

Note that one instrument may perform the tasks

of more than one category listed here Also more

than one instrument may be needed to carry out

tasks in a single category In the following sections

we will provide some examples of the types of

vibration instrumentation giving characteristics

operating principles and important practical

considerations Also we will describe several

experiments which can be found in a typical

vibration laboratory

An experimental vibration system generally

consists of four main subsystems

1 Test object

2 Excitation system

3 Control system

4 Signal acquisition and modification system

These are schematically shown in Figure 12 Note that various components shown in Figure 11 may

be incorporated into one of these subsystems In particular component matching hardware and object

mounting fixtures may be considered interfacing devices that are introduced through the interaction

between the main subsystems as shown in Figure 12 Some important issues of vibration testing and

instrumentation are summarized in Box 11

12 Vibration Exciters

Vibration experimentation may require an external exciter to generate the necessary vibration This is the

case in controlled experiments such as product testing where a specified level of vibration is applied to the

test object and the resulting response is monitored A variety of vibration exciters are available with

different capabilities and principles of operation

Three basic types of vibration exciters (shakers) are widely used hydraulic shakers inertial shakers

and electromagnetic shakers The operation-capability ranges of typical exciters in these three categories

are summarized in Table 11 Stroke or maximum displacement is the largest displacement the exciter

is capable of imparting onto a test object whose weight is assumed to be within its design load limit

Maximum velocity and acceleration are similarly defined Maximum force is the largest force that could

be applied by the shaker to a test object of acceptable weight (one within the design load) The values

given in Table 11 should be interpreted with caution Maximum displacement is achieved only at very

low frequencies The achievement of maximum velocity corresponds to intermediate frequencies in the

operating frequency range of the shaker Maximum acceleration and force ratings are usually achieved at

high frequencies It is not feasible for example to operate a vibration exciter at its maximum

displacement and its maximum acceleration simultaneously

Consider a loaded exciter that is executing harmonic motion Its displacement is given by

x frac14 s sin vt eth11THORN

in which s is the displacement amplitude (or stroke) Corresponding velocity and acceleration are

_x frac14 sv cos vt eth12THORN

eurox frac14 2sv2sin vt eth13THORN

SignalModification

System

TestObject

ControlSystem

VibrationExciter (Shaker)

System

FIGURE 12 Interactions between major subsystems of

an experimental vibration system

Vibration Instrumentation 1-3

53191mdash522007mdash1201mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

If the velocity amplitude is denoted by v and the acceleration amplitude by a it follows from Equation

12 and Equation 13 thatv frac14 vs eth14THORN

and

a frac14 vv eth15THORN

Box 11

VIBRATION INSTRUMENTATION

Vibration Testing Applications for Products

Design and Development Production Screening and Quality Assessment Utilization and Qualification for Special Applications

Testing Instrumentation

Exciter (excites the test object) Controller (controls the exciter for accurate excitation) Sensors and Transducers (measure excitations and responses and provide excitation error

signals to controller) Signal Conditioning (converts signals to appropriate form) Recording and Display (perform processing storage and documentation)

Exciters

Shakers

1 Electrodynamic (high bandwidth moderate power complex and multifrequency

excitations)

2 Hydraulic (moderate to high bandwidth high power complex and multifrequency

excitations)

3 Inertial (low bandwidth low power single-frequency harmonic excitations)

TransientInitial Condition

1 Hammers (impulsive bump tests)

2 Cable Release (step excitations)

3 Drop (impulsive)

Signal Conditioning

Filters Amplifiers Amplifiers ModulatorsDemodulators ADCDAC

Sensors

Motion (displacement velocity acceleration) Force (strain torque)

Vibration Monitoring Testing and Instrumentation1-4

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copy 2007 by Taylor amp Francis Group LLC

TABLE 11 Typical Operation-Capability Ranges for Various Shaker Types

Shaker Type Typical Operational Capabilities

Frequency Maximum Displacement

(Stroke)

Maximum

Velocity

Maximum

Acceleration

Maximum

Force

Excitation

Waveform

Hydraulic

(electrohydraulic)

Low

(01ndash500 Hz)

High (20 in 50 cm) Intermediate

(50 insec

125 cmsec)

Intermediate

(20 g)

High (100000 lbf

450000 N)

Average flexibility (simple

to complex and random)

Inertial

(counter-rotating mass)

Intermediate

(2ndash50 Hz)

Low (1 in 25 cm) Intermediate

(50 insec

125 cmsec)

Intermediate

(20 g)

Intermediate

(1000 lbf 4500 N)

Sinusoidal only

Electromagnetic

(electrodynamic)

High

(2ndash10000 Hz)

Low (1 in 25 cm) Intermediate

(50 insec

125 cmsec)

High (100 g) Low to intermediate

(450 lbf 2000 N)

High flexibility and accuracy

(simple to complex and

random)

VibrationInstru

mentation

1-5

53191mdash522007mdash

1201mdashSENTHILKUMARmdash246494mdash

CRCndashpp1ndash112

copy 2007 by Taylor amp Francis Group LLC

An idealized performance curve of a shaker

has a constant displacementndashamplitude region a

constant velocityndashamplitude region and a con-

stant accelerationndashamplitude region for low

intermediate and high frequencies respectively

in the operating frequency range Such an ideal

performance curve is shown in Figure 13(a) on a

frequencyndashvelocity plane Logarithmic axes are

used In practice typical shaker performance

curves would be fairly smooth yet nonlinear

curves similar to those shown in Figure 13(b)

As the mass increases the performance curve

compresses Note that the acceleration limit of a

shaker depends on the mass of the test object

(load) Full load corresponds to the heaviest object

that could be tested The ldquono loadrdquo condition

corresponds to a shaker without a test object To

standardize the performance curves they are

usually defined at the rated load of the shaker A

performance curve in the frequencyndashvelocity

plane may be converted to a curve in the

frequencyndashacceleration plane simply by increasing

the slope of the curve by a unit magnitude (ie

20 dbdecade)

Several general observations can be made from

Equation 14 and Equation 15 In the constant-

peak displacement region of the performance

curve the peak velocity increases proportionally

with the excitation frequency and the peak

acceleration increases with the square of the excitation frequency In the constant-peak velocity region

the peak displacement varies inversely with the excitation frequency and the peak acceleration increases

proportionately In the constant-peak acceleration region the peak displacement varies inversely with the

square of the excitation frequency and the peak velocity varies inversely with the excitation frequency

This further explains why rated stroke maximum velocity and maximum acceleration values are not

simultaneously realized

121 Shaker Selection

Vibration testing is accomplished by applying a specified excitation to the test package using a shaker

apparatus and monitoring the response of the test object Test excitation may be represented by its

response spectrum The test requires that the response spectrum of the actual excitation known as the

test response spectrum (TRS) envelops the response spectrum specified for the particular test known as

the required response spectrum (RRS)

A major step in the planning of any vibration testing program is the selection of a proper shaker

(exciter) system for a given test package The three specifications that are of primary importance in

selecting a shaker are the force rating the power rating and the stroke (maximum displacement) rating

Force and power ratings are particularly useful in moderate to high frequency excitations and the stroke

rating is the determining factor for low frequency excitations In this section a procedure is given to

determine conservative estimates for these parameters in a specified test for a given test package

Frequency domain considerations are used here

Stroke

Limit M

ax

Acceleration

MaxVelocity

Peak

Vel

ocity

(cm

s)

01 1 10 100

FullLoad

NoLoad

Frequency (Hz)(a)

Peak

Vel

ocity

(cm

s)

100

10

1

100

10

1

01 1 10 100

FullLoad

NoLoad

Frequency (Hz)(b)

FIGURE 13 Performance curve of a vibration exciter

in the frequencyndashvelocity plane (log) (a) ideal (b)

typical

Vibration Monitoring Testing and Instrumentation1-6

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copy 2007 by Taylor amp Francis Group LLC

1211 Force Rating

In the frequency domain the (complex) force at the exciter (shaker) head is given by

F frac14 mHethvTHORNasethvTHORN eth16THORNin which v is the excitation frequency variable m is the total mass of the test package including

mounting fixture and attachments asethvTHORN is the Fourier spectrum of the support-location (exciter head)

acceleration and H(v) is frequency response function that takes into account the flexibility and

damping effects (dynamics) of the test package apart from its inertia In the simplified case where the

test package can be represented by a simple oscillator of natural frequency vn and damping ratio by zt

this function becomes

HethvTHORN frac14 1thorn 2jztv=vn=12 ethv=vnTHORN2 thorn 2jztv=vn eth17THORNin which j frac14 ffiffiffiffi

21p

This approximation is adequate for most practical purposes The static weight of the

test object is not included in Equation 16 Most heavy-duty shakers which are typically hydraulic

have static load support systems such as pneumatic cushion arrangements that can exactly balance the

dead load The exciter provides only the dynamic force In cases where shaker directly supports the

gravity load in the vertical test configuration Equation 16 should be modified by adding a term to

represent this weight

A common practice in vibration test applications is to specify the excitation signal by its response

spectrum This is simply the peak response of a simple oscillator expressed as a function of its natural

frequency when its support location is excited by the specified signal Clearly the damping of the simple

oscillator is an added parameter in a response spectrum specification Typical damping ratios ethzrTHORN used inresponse spectra specifications are less than 01 (or 10) It follows that an approximate relationship

between the Fourier spectrum of the support acceleration and its response spectrum is

as frac14 2jzrarethvTHORN eth18THORNThe magnitude larethvTHORNl is the response spectrumEquation 18 substituted into Equation 16 gives

F frac14 mHethvTHORN2jzrarethvTHORN eth19THORNIn view of Equation 17 for test packages having low damping the peak value of H(v) is

approximately 1=eth2jztTHORN this should be used in computing the force rating if the test package has a

resonance within the frequency range of testing On the other hand if the test package is assumed to be

rigid then HethvTHORN oslash 1 A conservative estimate for the force rating is

Fmax frac14 methzr=ztTHORNlarethvTHORNlmax eth110THORNIt should be noted that larethvTHORNlmax is the peak value of the specified (required) response spectrum (RRS)

for acceleration

1212 Power Rating

The exciter head does not develop its maximum force when driven at maximum velocity Output power

is determined by using

p frac14 Refrac12FvsethvTHORN eth111THORNin which vsethvTHORN is the Fourier spectrum of the exciter velocity and Re [ ] denotes the real part of a complex

function Note that as frac14 jvvs Substituting Equation 16 and Equation 18 into Equation 111 gives

p frac14 eth4mz2r =vTHORNRefrac12jHethvTHORNa2r ethvTHORN eth112THORNIt follows that a conservative estimate for the power rating is

pmax frac14 2methz2r =ztTHORNfrac12larethvTHORNl2=v max eth113THORN

Vibration Instrumentation 1-7

53191mdash522007mdash1201mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

Representative segments of typical acceleration RRS curves have slope n as given by

a frac14 k1vn eth114THORN

It should be clear from Equation 113 that the maximum output power is given by

pmax frac14 k2v2n21 eth115THORN

This is an increasing function for n 1=2 and a decreasing function for n 1=2 It follows that the power

rating corresponds to the highest point of contact between the acceleration RRS curve and a line of slope

equal to 12 A similar relationship may be derived if velocity RRS curves (having slopes n2 1) are used

1213 Stroke Rating

From Equation 18 it should be clear that the Fourier spectrum xs of the exciter displacement time

history can be expressed as

xs frac14 2zrarethvTHORN=jv2 eth116THORNAn estimate for stroke rating is

xmax frac14 2zrfrac12larethvTHORNl=v2 max eth117THORNThis is of the form

xmax frac14 kvn22 eth118THORNIt follows that the stroke rating corresponds to the highest point of contact between the acceleration

RRS curve and a line of slope equal to two

Example 11

A test package of overall mass 100 kg is to be

subjected to dynamic excitation represented by the

acceleration RRS (at 5 damping) as shown in

Figure 14 The estimated damping of the test

package is 7 The test package is known to have a

resonance within the frequency range of the

specified test Determine the exciter specifications

for the test

Solution

From the development presented in the previous

section it is clear that the point F (or P) in

Figure 14 corresponds to the force and output

power ratings and the point S corresponds to

the stroke rating The co-ordinates of these

critical points are F P frac14 eth42 Hz 40 gTHORN and S frac14 eth08 Hz 075 gTHORN Equation 110 gives the force

rating as

Fmax frac14 100 pound eth005=007THORN pound 40 pound 981 N frac14 2803 N

Equation 113 gives the power rating as

pmax frac14 2 pound 100 pound eth0052=007THORN pound frac12eth40 pound 981THORN2=42 pound 2p watts frac14 417 W

Equation 117 gives the stroke rating as

xmax frac14 2 pound 005 pound frac12eth075 pound 98THORN=eth08 pound 2pTHORN2 m frac14 3 cm

Acc

eler

atio

n(g

)

Con

stan

t Dis

plac

emen

t

Constant Velo

city

Frequency (Hz)

S

FP

0101

10 10 100

10

10

FIGURE 14 Test excitation specified by an accelera-

tion RRS (5 damping)

Vibration Monitoring Testing and Instrumentation1-8

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copy 2007 by Taylor amp Francis Group LLC

1214 Hydraulic Shakers

A typical hydraulic shaker consists of a piston-cylinder arrangement (also called a ram) a servo-valve a

fluid pump and a driving electric motor Hydraulic fluid (oil) is pressurized (typical operating pressure

4000 psi) and pumped into the cylinder through a servo-valve by means of a pump that is driven by an

electric motor (typical power 150 hp) The flow (typical rate 100 galmin) that enters the cylinder is

controlled (modulated) by the servo-valve which in effect controls the resulting piston (ram) motion

A typical servo-valve consists of a two-stage spool valve which provides a pressure difference and a

controlled (modulated) flow to the piston which sets it in motion

The servo-valve itself is moved by means of a linear torque motor which is driven by the excitation-

input signal (electrical) A primary function of the servo-valve is to provide a stabilizing feedback to the

ram In this respect the servo-valve complements the main control system of the test setup The ram is

coupled to the shaker table by means of a link with some flexibility The cylinder frame is mounted on the

support foundation with swivel joints This allows for some angular and lateral misalignment which

might be caused primarily by test-object dynamics as the table moves

Two-degree-of-freedom (Two-DoF) testing requires two independent sets of actuators and three-DoF

testing requires three independent actuator sets Each independent actuator set can consist of several

actuators operated in parallel using the same pump and the same excitation-input signal to the torque

motors

If the test table is directly supported on the vertical actuators they must withstand the total dead

weight (ie the weight of the test table the test object the mounting fixtures and the instrumentation)

This is requirement is usually prevented by providing a pressurized air cushion in the gap between the

test table and the foundation walls Air should be pressurized so as to balance the total dead weight

exactly (typical required gage pressure 3 psi)

Figure 15(a) shows the basic components of a typical hydraulic shaker The corresponding

operational block diagram is shown in Figure 15(b) It is desirable to locate the actuators in a pit in the

test laboratory so that the test tabletop is flushed with the test laboratory floor under no-load conditions

This minimizes the effort required to place the test object on the test table Otherwise the test object has

to be lifted onto the test table with a forklift Also installation of an aircushion to support the system

dead weight is difficult under these circumstances of elevated mounting

Hydraulic actuators are most suitable for heavy load testing and are widely used in industrial and civil

engineering applications They canbeoperated at very low frequencies (almost direct current [DC]) aswell

as at intermediate frequencies (see Table 11) Large displacements (stroke) are possible at low frequencies

Hydraulic shakers have the advantage of providing high flexibility of operation during the test their

capabilities include variable-force and constant-force testing and wide-band random-input testing The

velocity and acceleration capabilities of hydraulic shakers are moderate Although any general excitation-

input motion (for example sine wave sine beat wide-band random) can be used in hydraulic shakers

faithful reproduction of these signals is virtually impossible at high frequencies because of distortion and

higher-order harmonics introduced by the high noise levels that are common in hydraulic systems This

is only a minor drawback in heavy-duty intermediate-frequency applications Dynamic interactions are

reduced through feedback control

1215 Inertial Shakers

In inertial shakers or ldquomechanical excitersrdquo the force that causes the shaker-table motion is generated by

inertia forces (accelerating masses) Counter-rotating-mass inertial shakers are typical in this category

To understand their principle of operation consider two equal masses rotating in opposite directions at

the same angular speed v and in the same circle of radius r (see Figure 16) This produces a resultant

force equal to 2mv2r cos vt in a fixed direction (the direction of symmetry of the two rotating arms)

Consequently a sinusoidal force with a frequency of v and an amplitude proportional to v2 is generated

This reaction force is applied to the shaker table

Figure 17 shows a sketch of a typical counter-rotating-mass inertial shaker It consists of two identical

rods rotating at the same speed in opposite directions Each rod has a series of slots in which to

Vibration Instrumentation 1-9

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place weights In this manner the magnitude of

the eccentric mass can be varied to achieve various

force capabilities The rods are driven by a

variable-speed electric motor through a gear

mechanism that usually provides several speed

ratios A speed ratio is selected depending on the

required test-frequency range The whole system is

symmetrically supported on a carriage that is

directly connected to the test table The test object

is mounted on the test table The preferred

mounting configuration is horizontal so that the

excitation force is applied to the test object in a

horizontal direction In this configuration there

are no variable gravity moments (weight pounddistance to center of gravity) acting on the drive

mechanism Figure 17 shows the vertical con-

figuration In dynamic testing of large structures

the carriage can be mounted directly on the

structure at a location where the excitation force

should be applied By incorporating two pairs of

counter-rotating masses it is possible to generate

test moments as well as test forces

FIGURE 15 A typical hydraulic shaker arrangement (a) schematic diagram (b) operational block diagram

m m

2mw2r cos wt

wtw w

wt

FIGURE 16 Principle of operation of a counter-

rotating-mass inertial shaker

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Reaction-type shakers driven by inertia are widely used for the prototype testing of civil engineering

structures Their first application dates back to 1935 Inertial shakers are capable of producing

intermediate excitation forces The force generated is limited by the strength of the carriage frame The

frequency range of operation and the maximum velocity and acceleration capabilities are also

intermediate for inertial shakers whereas the maximum displacement capability is typically low A major

limitation of inertial shakers is that their excitation force is exclusively sinusoidal and that the force

amplitude is directly proportional to the square of the excitation frequency As a result complex and

random excitation testing constant-force testing (for example transmissibility tests and constant-force

sine-sweep tests) and flexibility to vary the force amplitude or the displacement amplitude during a test

are not generally feasible with this type of shakers Excitation frequency and amplitude can be varied

during testing however by incorporating a variable-speed drive for the motor The sinusoidal excitation

generated by inertial shakers is virtually undistorted which gives them an advantage over the other types

of shakers when used in sine-dwell and sine-sweep tests Small portable shakers with low-force capability

are available for use in on-site testing

1216 Electromagnetic Shakers

In electromagnetic shakers or ldquoelectrodynamic excitersrdquo the motion is generated using the principle of

operation of an electric motor Specifically the excitation force is produced when a variable excitation

signal (electrical) is passed through a moving coil placed in a magnetic field

The components of a commercial electromagnetic shaker are shown in Figure 18 A steady magnetic

field is generated by a stationary electromagnet that consists of field coils wound on a ferromagnetic base

that is rigidly attached to a protective shell structure The shaker head has a coil wound around it When

the excitation electrical signal is passed through this drive coil the shaker head which is supported on

flexure mounts will be set in motion The shaker head consists of the test table on which the test object

is mounted Shakers with interchangeable heads are available The choice of appropriate shaker head is

based on the geometry and mounting features of the test object The shaker head can be turned to

different angles by means of a swivel joint In this manner different directions of excitation (in biaxial

and triaxial testing) can be obtained

FIGURE 17 Sketch of a counter-rotating-mass inertial shaker

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122 Dynamics of Electromagnetic Shakers

Consider a single axis electromagnetic shaker (Figure 18) with a test object having a single natural

frequency of importance within the test frequency range The dynamic interactions between the shaker

and the test object give rise to two significant natural frequencies (and correspondingly two significant

resonances) These appear as peaks in the frequency response curve of the test setup Furthermore the

natural frequency (resonance) of the test package alone causes a ldquotroughrdquo or depression (antiresonance)

in the frequency response curve of the overall test setup To explain this characteristic consider the

dynamic model shown in Figure 19 The following mechanical parameters are defined for

Figure 19(a) m k and b are the mass stiffness and equivalent viscous damping constant respectively

of the test package and me ke and be are the corresponding parameters of the exciter (shaker) Also in

the equivalent electrical circuit of the shaker head as shown in Figure 19(b) the following electrical

parameters are defined Re and Le are the resistance and (leakage) inductance and kb is the back

electromotive force (back emf) of the linear motor Assuming that the gravitational forces are supported

FIGURE 18 Schematic sectional view of a typical electromagnetic shaker manufactured by Bruel and Kjaer

Denmark

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by the static deflections of the flexible elements and that the displacements are measured from the static

equilibrium position we have the following system equations

Test object meuroy frac14 2kethy2 yeTHORN2 beth_y2 _yeTHORN eth119THORNShaker head me euroye frac14 fe thorn kethy2 yeTHORN thorn beth_y2 _yeTHORN2 key 2 be _ye eth120THORN

Electrical Lediedt

thorn Reie thorn kb _ye frac14 vethtTHORN eth121THORN

The electromagnetic force fe generated in the shaker head is a result of the interaction of the magnetic

field generated by the current ie with coil of the moving shaker head and the constant magnetic field

(stator) in which the head coil is located Here we have

fe frac14 kbie eth122THORNNote that v(t) is the voltage signal that is applied by the amplifier to the shaker coil ye is the displacement

of the shaker head and y is the displacement response of the test package

It is assumed that kb has consistent electrical and mechanical units (Vmsec and NA) Usually

the electrical time constant of the shaker is quite small compared with the primarily mechanical

time constants of the shaker and the test package In such cases the Ledie=dt term in Equation 121 may

be neglected Consequently the equations from Equation 119 through Equation 122 may be

expressed in the Laplace (frequency) domain with the Laplace variable s taking the place of the derivative

d=dt as

ethms2 thorn bsthorn kTHORNy frac14 ethbsthorn kTHORNye eth123THORN

FIGURE 19 Dynamic models of an electromagnetic shaker and a flexible test package (a) mechanical model

(b) electrical model

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frac12mes2 thorn ethbthorn beTHORNsthorn ethkthorn keTHORN ye frac14 ethbsthorn kTHORNy thorn kb

Rev2

k2bs

Reye eth124THORN

It follows that the transfer function of the shaker head motion with respect to the excitation voltage is

given by

yevfrac14 kb

Re

DethsTHORNDdethsTHORN eth125THORN

where DethsTHORN is the characteristic function of the primary dynamics of the test object

DethsTHORN frac14 ms2 thorn bsthorn k eth126THORN

and DdethsTHORN is the characteristic function of the primary dynamic interactions between the shaker and thetest object

DcethsTHORN frac14 mmes4 thorn frac12methbe thorn bthorn boTHORN thornmeb s

3 thorn frac12methke thorn kTHORN thornmekthorn bethbe thorn boTHORN s2thorn frac12bke thorn ethbe thorn boTHORNk sthorn kke

eth127THORN

where

bo frac14 k2bRe

eth128THORN

It is clear that under low damping conditions DdethsTHORN will produce two resonances as it is fourth order in sand similarly DethsTHORN will produce one antiresonance (trough) corresponding to the resonance of the testobject Note that in the frequency domain s frac14 jv and hence the frequency response function given by

Equation 125 is in fact

yevfrac14 kb

Rb

DethjvTHORNDdethjvTHORN eth129THORN

The magnitude of this frequency response function for a typical test system is sketched in Figure 110

Note that this curve is for the ldquoopen-looprdquo case where there is no feedback from the shaker controller

In practice the shaker controller will be able

to compensate for the resonances and anti-

resonances to some degree depending on its

effectiveness

The main advantages of electromagnetic

shakers are their high frequency range of

operation their high degree of operating flexi-

bility and the high level of accuracy of the

generated shaker motion Faithful reproduction

of complex excitations is possible because of the

advanced electronics and control systems used in

this type of shakers Electromagnetic shakers are

not suitable for heavy-duty applications (large test

objects) however High test-input accelerations

are possible at high frequencies when electromag-

netic shakers are used but their displacement and

velocity capabilities are limited to low or

intermediate values (see Table 11)

100

10

1 10 100Excitation Frequency (Hz)

Antiresonance

Resonance

Shak

erD

ispl

acem

entM

agni

tude

Resonance

1000

FIGURE 110 Frequency response curve of a typical

electromagnetic shaker with a test object

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1221 Transient Exciters

Other varieties of exciters are commonly used in

transient-type vibration testing In these tests

either an impulsive force or an initial excitation is

applied to the test object and the resulting

response is monitored The excitations and the

responses are ldquotransientrdquo in this case Hammer

test drop tests and pluck tests fall into this

category For example a hammer test may be

conducted by hitting the object with an instru-

mented hammer and then measuring the response

of the object The hammer has a force sensor at its

tip as sketched in Figure 111 A piezoelectric or

strain-gage type force sensor may be used More

sophisticated hammers have impedance heads in

place of force sensors An impedance head

measures force and acceleration simultaneously

The results of a hammer test will depend on many

factors for example the dynamics of the hammer

body how firmly the hammer is held during the

impact how quickly the impact is applied and

whether there are multiple impacts

13 Control System

The two primary functions of the shaker control system in vibration testing are (1) to guarantee that the

specified excitation is applied to the test object and (2) to ensure that the dynamic stability (motion

constraints) of the test setup is preserved An operational block diagram illustrating these control

functions is given in Figure 112 The reference input to the control system represents the desired

excitation force that should be applied to the test object In the absence of any control however the force

reaching the test object will be distorted primarily because of (1) dynamic interactions and

nonlinearities of the shaker the test table the mounting fixtures the auxiliary instruments and the test

object itself (2) noise and errors in the signal generator amplifiers filters and other equipment and (3)

external loads and disturbances acting on the test object and other components (for example external

restraints aerodynamic forces friction) To compensate for these distorting factors response

measurements (displacements velocities acceleration and so on) are made at various locations in the

test setup and are used to control the system dynamics In particular the responses of the shaker the test

table and the test object are measured These responses are used to compare the actual excitation felt by

FIGURE 111 An instrumented hammer used in bump

tests or hammer tests

ExcitationInput

(Reference)

Feedback Paths

DriveSignal

ShakerResponse

TestTable

TestObject

Test ObjectResponse

Test TableResponseExciter

(Shaker)(Ram)

Controllerand

Amplifier

FIGURE 112 Operational block diagram illustrating a general shaker control system

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the test object at the shaker interface with the desired (specified) input The drive signal to the shaker is

modified depending on the error that is present

Two types of control are commonly employed in shaker apparatus simple manual control and

complex automatic control Manual control normally consists of simple open-loop trial-and-error

methods of manual adjustments (or calibration) of the control equipment to obtain a desired dynamic

response The actual response is usually monitored (on an oscilloscope or frequency analyzer screen for

example) during manual-control operations The pretest adjustments in manual control can be very

time-consuming as a result the test object might be subjected to overtesting which could produce

cumulative damage is undesirable and could defeat the test purpose Furthermore the calibration

procedure for the experimental setup must be repeated for each new test object

The disadvantages ofmanual control suggest that automatic control is desirable in complex test schemes

in which high accuracy of testing is desired The first step of automatic control involves automatic

measurement of the system response using control sensors and transducers The measurement is then fed

back into the control system which instantaneously determines the best drive signal to actuate the shaker

in order to get the desired excitation This may be done by either analog or digital methods

Primitive control systems require an accurate mathematical description of the test object This

dependency of the control system on the knowledge of test-object dynamics is clearly undesirable

Performance of a good control system should not be considerably affected by the dynamic interactions

and nonlinearities of the test object or by the nature of the excitation Proper selection of feedback signals

and control-system components can reduce such effects and will make the system robust

In the response-spectrum method of vibration testing it is customary to use displacement control at

low frequencies velocity control at intermediate frequency and acceleration control at high frequencies

This necessitates feedback of displacement velocity and acceleration responses Generally however the

most important feedback is the velocity feedback In sine-sweep tests the shaker velocity must change

steadily over the frequency band of interest In particular the velocity control must be precise near the

resonances of the test object Velocity (speed) feedback has a stabilizing effect on the dynamics which is

desirable This effect is particularly useful in ensuring stability in motion when testing is done near

resonances of lightly damped test objects On the contrary displacement (position) feedback can have a

destabilizing effect on some systems particularly when high feedback gains are used

The controller usually consists of various instruments equipment and computation hardware and

software Often the functions of the data-acquisition and processing system overlap with those of the

controller to some extent As an example consider the digital-controller of vibration testing apparatus

First the responses are measured through sensors (and transducers) filtered and amplified

(conditioned) These data channels may be passed through a multiplexer whose purpose is to select

one data channel at a time for processing Most modern data acquisition hardware does not need a

separate multiplexer to handle multiple signals The analog data are converted into digital data using

analog-to-digital converters (ADCs) The resulting sampled data are stored on a disk or as a block data in

the computer memory The reference input signal (typically a signal recorded on an FM tape) is also

sampled (if it is not already in the digital form) using an ADC and fed into the computer Digital

processing is done on the reference signal and the response data with the objective of computing the

command signal to drive the shaker The digital command signal is converted into an analog signal using

a digital-to-analog converter (DAC) and amplified (conditioned) before it is used to drive the exciter

The nature of the control components depends to a large extent on the nature and objectives of the

particular test to be conducted Some of the basic components in a shaker controller are described in

the following subsections

131 Components of a Shaker Controller

1311 Compressor

A compressor circuit is incorporated in automatic excitation control devices to control the excitation-

input level automatically The level of control depends on the feedback signal from a control sensor and

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the specified (reference) excitation signal Usually the compressor circuit is included in the excitation-

signal generator (for example in a sine generator) The control by this means may be done on the basis of

a single-frequency component (eg the fundamental frequency)

1312 Equalizer (Spectrum Shaper)

Random-signal equalizers are used to shape the spectrum of a random signal in a desired manner In

essence and equalizer consists of a bank of narrow-band filters (for example 80 filters) in parallel over

the operating frequency range By passing the signal through each filter the spectral density (or the mean

square value) of the signal in that narrow frequency band (for example each one-third-octave band) is

determined This is compared with the desired spectral level and automatic adjustment is made in that

filter in case there is an error In some systems response-spectrum analysis is made in place of power

spectral density analysis In that case the equalizer consists of a bank of simple oscillators whose

resonant frequencies are distributed over the operating frequency range of the equalizer The feedback

signal is passed through each oscillator and the peak value of its output is determined This value is

compared with the desired response spectrum value at that frequency If there is an error automatic gain

adjustment is made in the appropriate excitation signal components

Random-noise equalizers are used in conjunction with random signal generators They receive

feedback signals from the control sensors In some digital control systems there are algorithms (software)

that are used to iteratively converge the spectrum of the excitation signal felt by the test object into the

desired spectrum

1313 Tracking Filter

Many vibration tests are based on single-frequency excitations In such cases the control functions

should be performed on the basis of the amplitudes of the fundamental-frequency component of the

signal A tracking filter is simply a frequency-tuned band-pass filter It automatically tunes the center

frequency of its very narrow-band-pass filter to the frequency of a carrier signal Then when a noisy

signal is passed through the tuned filter the output of the filter will be the required fundamental

frequency component in the signal Tracking filters also are useful in obtaining amplitudendashfrequency

plots using an XndashY plotter In such cases the frequency value comes from the signal generator (sweep

oscillator) which produces the carrier signal to the tracking filter The tracking filter then determines the

corresponding amplitude of a signal that is fed into it Most tracking filters have dual channels so that two

signals can be handled (tracked) simultaneously

1314 Excitation Controller (Amplitude Servo-Monitor)

An excitation controller is typically an integral part of the signal generator It can be set so that automatic

sweep between two frequency limits can be performed at a selected sweep rate (linear or logarithmic)

More advanced excitation controllers have the capability of an automatic switch-over between constant-

displacement constant-velocity and constant-acceleration excitation-input control at specified

frequencies over the sweep frequency interval Consequently integrator circuits should be present

within the excitation controller unit to determine velocities and displacements from acceleration signals

Sometimes integration is performed by a separate unit called a vibration meter This unit also offers

the operator the capability of selecting the desired level of each signal (acceleration velocity or

displacement) There is an automatic cut-off level for large displacement values that could result from

noise in acceleration signals A compressor is also a subcomponent of the excitation controller The

complete unit is sometimes known as an amplitude servo-monitor

132 Signal-Generating Equipment

Shakers are force-generating devices that are operated using drive (excitation) signals generated from a

source The excitation-signal source is known as the signal generator Three major types of signal

generators are used in vibration testing applications (1) oscillators (2) random-signal generators and

(3) storage devices In some units oscillators and random-signal generators are combined We shall

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copy 2007 by Taylor amp Francis Group LLC

discuss these two generators separately however because of their difference in function It also should be

noted that almost any digital signal (deterministic or random) can be generated by a digital computer

using a suitable computer program the signal eventually can be passed through a DAC to obtain

the corresponding analog signal These lsquodigitalrsquo signal generators along with analog sources such as

magnetic tape players (FM) are classified into the category of storage devices

The dynamic range of equipment is the ratio of the maximum and minimum output levels (expressed

in decibels) at which it is capable of operating without significant error This is an important specification

for many types of equipment particularly for signal-generating devices The output level of the signal

generator should be set to a value within its dynamic range

1321 Oscillators

Oscillators are essentially single-frequency generators Typically sine signals are generated but other

waveforms (such as rectangular and triangular pulses) are also available in most oscillators Normally

an oscillator has two modes of operation (1) sweeping up and down between two frequency limits and

(2) dwelling at a specified frequency In the sweep operation the sweep rate should be specified This can

be done either on a linear scale (Hzmin) or on a logarithmic scale (octavesmin) In the dwell operation

the frequency points (or intervals) should be specified In either case a desired signal level can be chosen

using the gain-control knob An oscillator that is operated exclusively in the sweep mode is called a sweep

oscillator

The early generation of oscillators employed variable inductor-capacitor types of electronic circuits to

generate signals oscillating at a desired frequency The oscillator is tuned to the required frequency by

varying the capacitance or inductance parameters A DC voltage is applied to energize the capacitor

and to obtain the desired oscillating voltage signal which subsequently is amplified and conditioned

Modern oscillators use operational amplifier circuits along with resistor capacitor and semiconductor

(SC) elements Also common are crystal (quartz) parallel-resonance oscillators used to generate voltage

signals accurately at a fixed frequency The circuit is activated using a DC-voltage source Other

frequencies of interest are obtained by passing this high-frequency signal through a frequency converter

The signal is then conditioned (amplified and filtered) Required shaping (for example rectangular

pulse) is obtained using a shape circuit Finally the required signal level is obtained by passing the

resulting signal through a variable-gain amplifier A block diagram of an oscillator illustrating various

stages in the generation of a periodic signal is given in Figure 113

A typical oscillator offers a choice of several (typically six) linear and logarithmic frequency ranges and

a sizable level of control capability (for example 80 dB) Upper and lower frequency limits in a sweep can

be preset on the front panel to any of the available frequency ranges Sweep-rate settings are continuously

DC Voltage

Oscillator

FrequencySpecification

FrequencyConverter

FilterAmplifier

ShaperPeriodicSignal

FrequencyCounter

Fixed-FrequencySignal

Variable-GainOutput

Amplifier

SignalSpecification

LevelSpecification

FIGURE 113 Block diagram of an oscillator-type signal generator

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  • 53191fm
    • Vibration Monitoring Testing and Instrumentation
      • Preface
      • Acknowledgments
      • Editor-in-Chief
      • Contributors
      • Contents
      • Related Titles
          • 53191ch1
            • Table of Contents
            • Chapter 1 Vibration Instrumentation
              • Summary
              • 11 Introduction
              • 12 Vibration Exciters
                • 121 Shaker Selection
                  • 1211 Force Rating
                  • 1212 Power Rating
                  • 1213 Stroke Rating
                  • 1214 Hydraulic Shakers
                  • 1215 Inertial Shakers
                  • 1216 Electromagnetic Shakers
                    • 122 Dynamics of Electromagnetic Shakers
                      • 1221 Transient Exciters
                          • 13 Control System
                            • 131 Components of a Shaker Controller
                              • 1311 Compressor
                              • 1312 Equalizer (Spectrum Shaper)
                              • 1313 Tracking Filter
                              • 1314 Excitation Controller (Amplitude Servo-Monitor)
                                • 132 Signal-Generating Equipment
                                  • 1321 Oscillators
                                  • 1322 Random Signal Generators
                                  • 1323 Tape Players
                                  • 1324 Data Processing
                                      • 14 Performance Specification
                                        • 141 Parameters for Performance Specification
                                          • 1411 Time-Domain Specifications
                                          • 1412 Frequency-Domain Specifications
                                            • 142 Linearity
                                            • 143 Instrument Ratings
                                              • 1431 Rating Parameters
                                                • 144 Accuracy and Precision
                                                  • 15 Motion Sensors and Transducers
                                                    • 151 Potentiometer
                                                      • 1511 Potentiometer Resolution
                                                      • 1512 Optical Potentiometer
                                                        • 152 Variable-Inductance Transducers
                                                          • 1521 Mutual-Induction Transducers
                                                          • 1522 Linear-Variable Differential Transformer
                                                          • 1523 Signal Conditioning
                                                            • 153 Mutual-Induction Proximity Sensor
                                                            • 154 Selfinduction Transducers
                                                            • 155 Permanent-Magnet Transducers
                                                            • 156 Alternating Current Permanent-Magnet Tachometer
                                                            • 157 Alternating Current Induction Tachometer
                                                            • 158 Eddy Current Transducers
                                                            • 159 Variable-Capacitance Transducers
                                                              • 1591 Capacitive Displacement Sensors
                                                              • 1592 Capacitive Angular Velocity Sensor
                                                              • 1593 Capacitance Bridge Circuit
                                                                • 1510 Piezoelectric Transducers
                                                                  • 15101 Sensitivity
                                                                  • 15102 Piezoelectric Accelerometer
                                                                  • 15103 Charge Amplifier
                                                                      • 16 Torque Force and Other Sensors
                                                                        • 161 Strain Gage Sensors
                                                                          • 1611 Equations for Strain Gage Measurements
                                                                          • 1612 Bridge Sensitivity
                                                                          • 1613 The Bridge Constant
                                                                          • 1614 The Calibration Constant
                                                                          • 1615 Data Acquisition
                                                                          • 1616 Accuracy Considerations
                                                                          • 1617 Semiconductor Strain Gages
                                                                          • 1618 Force and Torque Sensors
                                                                          • 1619 Strain Gage Torque Sensors
                                                                          • 16110 Deflection Torque Sensors
                                                                          • 16111 Variable-Reluctance Torque Sensor
                                                                          • 16112 Reaction Torque Sensors
                                                                            • 162 Miscellaneous Sensors
                                                                              • 1621 Stroboscope
                                                                              • 1622 Fiber Optic Sensors and Lasers
                                                                              • 1623 Fiber-Optic Gyroscope
                                                                              • 1624 Laser Doppler Interferometer
                                                                              • 1625 Ultrasonic Sensors
                                                                              • 1626 Gyroscopic Sensors
                                                                                  • References
                                                                                  • Appendix 1A Virtual Instrumentation for Data Acquisition Analysis and Presentation
                                                                                    • Summary
                                                                                    • List of Abbreviations
                                                                                    • 1A1 Dynamic Signals
                                                                                      • 1A11 Acquiring and Simulating Dynamic Signals
                                                                                        • 1A111 Aliasing
                                                                                        • 1A112 Time Continuity
                                                                                            • 1A2 Measurement Configuration Considerations
                                                                                              • 1A21 Input Signal Considerations
                                                                                                • 1A211 Input Pseudodifferential and Differential Configuration
                                                                                                • 1A212 Gain
                                                                                                • 1A213 Input Coupling
                                                                                                • 1A214 Integrated Electronic Piezoelectric Excitation
                                                                                                • 1A215 Nyquist Frequency and Bandwidth
                                                                                                • 1A216 Analog-to-Digital Conversion
                                                                                                • 1A217 Antialias Filters
                                                                                                • 1A218 Input Filter Delay
                                                                                                • 1A219 Overload Detection
                                                                                                  • 1A22 Output Signal Considerations
                                                                                                    • 1A221 Output Pseudodifferential and Differential Configuration
                                                                                                    • 1A222 Attenuation
                                                                                                    • 1A223 Digital-to-Analog Conversion
                                                                                                    • 1A224 Anti-imaging and Interpolation Filters
                                                                                                    • 1A225 Output Filter Delay
                                                                                                        • 1A3 Scaling and Calibration
                                                                                                          • 1A31 Scaling to Engineering Units
                                                                                                          • 1A32 Performing System Calibration
                                                                                                            • 1A321 Propagation Delay Calibration
                                                                                                                • 1A4 Limit Testing Analysis
                                                                                                                  • 1A41 Limit Testing Overview
                                                                                                                  • 1A42 Using the SVT Limit Testing VI
                                                                                                                    • 1A5 Integration
                                                                                                                      • 1A51 Introduction to Integration
                                                                                                                      • 1A52 Implementing Integration
                                                                                                                        • 1A521 Challenges when Integrating Vibration Data
                                                                                                                          • 1A53 Time-Domain Integration
                                                                                                                            • 1A531 Single-Shot Acquisition and Integration
                                                                                                                            • 1A532 Continuous Acquisition and Integration
                                                                                                                              • 1A54 Frequency-Domain Integration
                                                                                                                                • 1A6 Vibration-Level Measurements
                                                                                                                                  • 1A61 Measuring the Root Mean Square Level
                                                                                                                                    • 1A611 Single-Shot Buffered Acquisition
                                                                                                                                    • 1A612 Continuous Signal Acquisition
                                                                                                                                      • 1A62 Performing a Running RMS Level Measurement
                                                                                                                                      • 1A63 Computing the Peak Level
                                                                                                                                      • 1A64 Computing the Crest Factor
                                                                                                                                        • 1A7 Frequency Analysis
                                                                                                                                          • 1A71 FFT Fundamentals
                                                                                                                                            • 1A711 Number of Samples
                                                                                                                                            • 1A712 Frequency Resolution
                                                                                                                                            • 1A713 Maximum Resolvable Frequency
                                                                                                                                            • 1A714 Minimum Resolvable Frequency
                                                                                                                                            • 1A715 Number of Spectral Lines
                                                                                                                                            • 1A716 Relationship between Time-Domain and Frequency-Domain Specifications and Parameters
                                                                                                                                              • 1A72 Increasing Frequency Resolution
                                                                                                                                                • 1A721 Zoom FFT Analysis
                                                                                                                                                • 1A722 Frequency Resolution of the Zoom FFT VIs
                                                                                                                                                • 1A723 Zoom Measurement
                                                                                                                                                • 1A724 Zoom Settings
                                                                                                                                                • 1A725 Subset Analysis
                                                                                                                                                    • 1A8 Transient Analysis
                                                                                                                                                      • 1A81 Transient Analysis with the Sound and Vibration Toolkit
                                                                                                                                                      • 1A82 Performing an STFT vs Time
                                                                                                                                                        • 1A821 Selecting the FFT Block Size
                                                                                                                                                        • 1A822 Overlapping
                                                                                                                                                        • 1A823 Using the SVT STFT vs Time VI
                                                                                                                                                          • 1A83 Performing an STFT vs Rotational Speed
                                                                                                                                                            • 1A831 Converting the Pulse Train to Rotational Speed
                                                                                                                                                            • 1A832 STFT vs RPM
                                                                                                                                                              • 1A84 Measuring a Shock Response Spectrum
                                                                                                                                                                • 1A9 Waterfall Display
                                                                                                                                                                  • 1A91 Using the Display VIs
                                                                                                                                                                    • 1A911 Initializing the Display
                                                                                                                                                                    • 1A912 Sending Data to the Display
                                                                                                                                                                    • 1A913 Waterfall Display for Frequency Analysis
                                                                                                                                                                    • 1A914 Waterfall Display for Transient Analysis
                                                                                                                                                                    • 1A915 Waterfall Display for Octave Spectra
                                                                                                                                                                        • 1A10 Swept-Sine Measurements
                                                                                                                                                                          • 1A101 Swept-Sine Overview
                                                                                                                                                                          • 1A102 Choosing Swept-Sine vs FFT Measurements
                                                                                                                                                                          • 1A103 Taking a Swept-Sine Measurement
                                                                                                                                                                          • 1A104 Swept-Sine Measurement Example
                                                                                                                                                                              • Bibliography
                                                                                                                                                                              • Related Titles
                                                                                                                                                                                  • 53191ch2
                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                    • Chapter 2 Signal Conditioning and Modification
                                                                                                                                                                                      • Summary
                                                                                                                                                                                      • 21 Introduction
                                                                                                                                                                                      • 22 Amplifiers
                                                                                                                                                                                        • 221 Operational Amplifier
                                                                                                                                                                                        • 222 Use of Feedback in Opamp
                                                                                                                                                                                        • 223 Voltage Current and Power Amplifiers
                                                                                                                                                                                          • 2231 Charge Amplifiers
                                                                                                                                                                                            • 224 Instrumentation Amplifiers
                                                                                                                                                                                              • 2241 Differential Amplifier
                                                                                                                                                                                              • 2242 Common Mode
                                                                                                                                                                                                • 225 Amplifier Performance Ratings
                                                                                                                                                                                                  • 2251 Common-Mode Rejection Ratio
                                                                                                                                                                                                    • 226 Component Interconnection
                                                                                                                                                                                                      • 2261 Impedance Characteristics
                                                                                                                                                                                                      • 2262 Cascade Connection of Devices
                                                                                                                                                                                                      • 2263 AC-Coupled Ampliers
                                                                                                                                                                                                          • 23 Analog Filters
                                                                                                                                                                                                            • 231 Passive Filters and Active Filters
                                                                                                                                                                                                              • 2311 Number of Poles
                                                                                                                                                                                                                • 232 Low-Pass Filters
                                                                                                                                                                                                                  • 2321 Low-Pass Butterworth Filter
                                                                                                                                                                                                                    • 233 High-Pass Filters
                                                                                                                                                                                                                    • 234 Band-Pass Filters
                                                                                                                                                                                                                      • 2341 Resonance-Type Band-Pass Filters
                                                                                                                                                                                                                        • 235 Band-Reject Filters
                                                                                                                                                                                                                          • 24 Modulators and Demodulators
                                                                                                                                                                                                                            • 241 Amplitude Modulation
                                                                                                                                                                                                                              • 2411 Modulation Theorem
                                                                                                                                                                                                                              • 2412 Side Frequencies and Side Bands
                                                                                                                                                                                                                                • 242 Application of Amplitude Modulation
                                                                                                                                                                                                                                  • 2421 Fault Detection and Diagnosis
                                                                                                                                                                                                                                    • 243 Demodulation
                                                                                                                                                                                                                                      • 25 Analog ndashDigital Conversion
                                                                                                                                                                                                                                        • 251 Digital-to-Analog Conversion
                                                                                                                                                                                                                                          • 2511 DAC Error Sources
                                                                                                                                                                                                                                            • 252 Analog-to-Digital Conversion
                                                                                                                                                                                                                                            • 253 Analog-to-Digital Converter Performance Characteristics
                                                                                                                                                                                                                                              • 2531 Resolution and Quantization Error
                                                                                                                                                                                                                                              • 2532 Monotonicity Nonlinearity and Offset Error
                                                                                                                                                                                                                                              • 2533 Analog-to-Digital Converter Conversion Rate
                                                                                                                                                                                                                                                • 254 Sample-and-Hold Circuitry
                                                                                                                                                                                                                                                • 255 Digital Filters
                                                                                                                                                                                                                                                  • 2551 Software Implementation and Hardware Implementation
                                                                                                                                                                                                                                                      • 26 Bridge Circuits
                                                                                                                                                                                                                                                        • 261 Wheatstone Bridge
                                                                                                                                                                                                                                                        • 262 Constant-Current Bridge
                                                                                                                                                                                                                                                        • 263 Bridge Amplifiers
                                                                                                                                                                                                                                                          • 2631 Half-Bridge Circuits
                                                                                                                                                                                                                                                            • 264 Impedance Bridges
                                                                                                                                                                                                                                                              • 2641 Owen Bridge
                                                                                                                                                                                                                                                              • 2642 Wien-Bridge Oscillator
                                                                                                                                                                                                                                                                  • 27 Linearizing Devices
                                                                                                                                                                                                                                                                    • 271 Linearization by Software
                                                                                                                                                                                                                                                                    • 272 Linearization by Hardware Logic
                                                                                                                                                                                                                                                                    • 273 Analog Linearizing Circuitry
                                                                                                                                                                                                                                                                    • 274 Offsetting Circuitry
                                                                                                                                                                                                                                                                    • 275 Proportional-Output Circuitry
                                                                                                                                                                                                                                                                      • 2751 Curve-Shaping Circuitry
                                                                                                                                                                                                                                                                          • 28 Miscellaneous Signal Modification Circuitry
                                                                                                                                                                                                                                                                            • 281 Phase Shifters
                                                                                                                                                                                                                                                                            • 282 Voltage-to-Frequency Converter
                                                                                                                                                                                                                                                                            • 283 Frequency-to-Voltage Converter
                                                                                                                                                                                                                                                                            • 284 Voltage-to-Current Converters
                                                                                                                                                                                                                                                                            • 285 Peak-Hold Circuits
                                                                                                                                                                                                                                                                              • 29 Signal Analyzers and Display Devices
                                                                                                                                                                                                                                                                                • 291 Signal Analyzers
                                                                                                                                                                                                                                                                                • 292 Oscilloscopes
                                                                                                                                                                                                                                                                                  • 2921 Triggering
                                                                                                                                                                                                                                                                                  • 2922 Lissajous Patterns
                                                                                                                                                                                                                                                                                  • 2923 Digital Oscilloscopes
                                                                                                                                                                                                                                                                                      • Bibliography
                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                          • 53191ch3
                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                            • Chapter 3 Vibration Testing
                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                              • 31 Introduction
                                                                                                                                                                                                                                                                                              • 32 Representation of a Vibration Environment
                                                                                                                                                                                                                                                                                                • 321 Test Signals
                                                                                                                                                                                                                                                                                                  • 3211 Stochastic vs Deterministic Signals
                                                                                                                                                                                                                                                                                                    • 322 Deterministic Signal Representation
                                                                                                                                                                                                                                                                                                      • 3221 Single-Frequency Signals
                                                                                                                                                                                                                                                                                                      • 3222 Sine Sweep
                                                                                                                                                                                                                                                                                                      • 3223 Sine Dwell
                                                                                                                                                                                                                                                                                                      • 3224 Decaying Sine
                                                                                                                                                                                                                                                                                                      • 3225 Sine Beat
                                                                                                                                                                                                                                                                                                      • 3226 Sine Beat with Pauses
                                                                                                                                                                                                                                                                                                      • 3227 Multifrequency Signals
                                                                                                                                                                                                                                                                                                      • 3228 Actual Excitation Records
                                                                                                                                                                                                                                                                                                      • 3229 Simulated Excitation Signals
                                                                                                                                                                                                                                                                                                        • 323 Stochastic Signal Representation
                                                                                                                                                                                                                                                                                                          • 3231 Ergodic Random Signals
                                                                                                                                                                                                                                                                                                          • 3232 Stationary Random Signals
                                                                                                                                                                                                                                                                                                          • 3233 Independent and Uncorrelated Signals
                                                                                                                                                                                                                                                                                                          • 3234 Transmission of Random Excitations
                                                                                                                                                                                                                                                                                                            • 324 Frequency-Domain Representations
                                                                                                                                                                                                                                                                                                              • 3241 Fourier Spectrum Method
                                                                                                                                                                                                                                                                                                              • 3242 Power Spectral Density Method
                                                                                                                                                                                                                                                                                                                • 325 Response Spectrum
                                                                                                                                                                                                                                                                                                                  • 3251 Displacement Velocity and Acceleration Spectra
                                                                                                                                                                                                                                                                                                                  • 3252 Response-Spectra Plotting Paper
                                                                                                                                                                                                                                                                                                                  • 3253 Zero-Period Acceleration
                                                                                                                                                                                                                                                                                                                  • 3254 Uses of Response Spectra
                                                                                                                                                                                                                                                                                                                    • 326 Comparison of Various Representations
                                                                                                                                                                                                                                                                                                                      • 33 Pretest Procedures
                                                                                                                                                                                                                                                                                                                        • 331 Purpose of Testing
                                                                                                                                                                                                                                                                                                                        • 332 Service Functions
                                                                                                                                                                                                                                                                                                                          • 3321 Active Equipment
                                                                                                                                                                                                                                                                                                                          • 3322 Passive Equipment
                                                                                                                                                                                                                                                                                                                          • 3323 Functional Testing
                                                                                                                                                                                                                                                                                                                            • 333 Information Acquisition
                                                                                                                                                                                                                                                                                                                              • 3331 Interface Details
                                                                                                                                                                                                                                                                                                                              • 3332 Effect of Neglecting Interface Dynamics
                                                                                                                                                                                                                                                                                                                              • 3333 Effects of Damping
                                                                                                                                                                                                                                                                                                                              • 3334 Effects of Inertia
                                                                                                                                                                                                                                                                                                                              • 3335 Effect of Natural Frequency
                                                                                                                                                                                                                                                                                                                              • 3336 Effect of Excitation Frequency
                                                                                                                                                                                                                                                                                                                              • 3337 Other Effects of Interface
                                                                                                                                                                                                                                                                                                                                • 334 Test-Program Planning
                                                                                                                                                                                                                                                                                                                                  • 3341 Testing of Cabinet-Mounted Equipment
                                                                                                                                                                                                                                                                                                                                    • 335 Pretest Inspection
                                                                                                                                                                                                                                                                                                                                      • 34 Testing Procedures
                                                                                                                                                                                                                                                                                                                                        • 341 Resonance Search
                                                                                                                                                                                                                                                                                                                                        • 342 Methods of Determining Frequency-Response Functions
                                                                                                                                                                                                                                                                                                                                          • 3421 Fourier Transform Method
                                                                                                                                                                                                                                                                                                                                          • 3422 Spectral Density Method
                                                                                                                                                                                                                                                                                                                                          • 3423 Harmonic Excitation Method
                                                                                                                                                                                                                                                                                                                                            • 343 Resonance-Search Test Methods
                                                                                                                                                                                                                                                                                                                                              • 3431 Hammer (Bump) Test and Drop Test
                                                                                                                                                                                                                                                                                                                                              • 3432 Pluck Test
                                                                                                                                                                                                                                                                                                                                              • 3433 Shaker Tests
                                                                                                                                                                                                                                                                                                                                                • 344 Mechanical Aging
                                                                                                                                                                                                                                                                                                                                                  • 3441 Equivalence for Mechanical Aging
                                                                                                                                                                                                                                                                                                                                                  • 3442 Excitation-Intensity Equivalence
                                                                                                                                                                                                                                                                                                                                                  • 3443 Dynamic-Excitation Equivalence
                                                                                                                                                                                                                                                                                                                                                  • 3444 Cumulative Damage Theory
                                                                                                                                                                                                                                                                                                                                                    • 345 Test-Response Spectrum Generation
                                                                                                                                                                                                                                                                                                                                                    • 346 Instrument Calibration
                                                                                                                                                                                                                                                                                                                                                    • 347 Test-Object Mounting
                                                                                                                                                                                                                                                                                                                                                    • 348 Test-Input Considerations
                                                                                                                                                                                                                                                                                                                                                      • 3481 Test Nomenclature
                                                                                                                                                                                                                                                                                                                                                      • 3482 Testing with Uncorrelated Excitations
                                                                                                                                                                                                                                                                                                                                                      • 3483 Symmetrical Rectilinear Testing
                                                                                                                                                                                                                                                                                                                                                      • 3484 Geometry vs Dynamics
                                                                                                                                                                                                                                                                                                                                                      • 3485 Some Limitations
                                                                                                                                                                                                                                                                                                                                                      • 3486 Testing Black Boxes
                                                                                                                                                                                                                                                                                                                                                      • 3487 Phasing of Excitations
                                                                                                                                                                                                                                                                                                                                                      • 3488 Testing a Gray or White Box
                                                                                                                                                                                                                                                                                                                                                      • 3489 Overtesting in Multitest Sequences
                                                                                                                                                                                                                                                                                                                                                          • 35 Some Practical Information
                                                                                                                                                                                                                                                                                                                                                            • 351 Random Vibration Test Example
                                                                                                                                                                                                                                                                                                                                                            • 352 Vibration Shakers and Control Systems
                                                                                                                                                                                                                                                                                                                                                              • Bibliography
                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                  • 53191ch4
                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                    • Chapter 4 Experimental Modal Analysis
                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                      • 41 Introduction
                                                                                                                                                                                                                                                                                                                                                                      • 42 Frequency-Domain Formulation
                                                                                                                                                                                                                                                                                                                                                                        • 421 Transfer-Function Matrix
                                                                                                                                                                                                                                                                                                                                                                        • 422 Principle of Reciprocity
                                                                                                                                                                                                                                                                                                                                                                          • 43 Experimental Model Development
                                                                                                                                                                                                                                                                                                                                                                            • 431 Extraction of the Time-Domain Model
                                                                                                                                                                                                                                                                                                                                                                              • 44 Curve Fitting of Transfer Functions
                                                                                                                                                                                                                                                                                                                                                                                • 441 Problem Identification
                                                                                                                                                                                                                                                                                                                                                                                • 442 Single- and Multi-Degree-of-Freedom Techniques
                                                                                                                                                                                                                                                                                                                                                                                • 443 Single-Degree-of-Freedom Parameter Extraction in the Frequency Domain
                                                                                                                                                                                                                                                                                                                                                                                  • 4431 Circle-Fit Method
                                                                                                                                                                                                                                                                                                                                                                                    • Case of Viscous Damping
                                                                                                                                                                                                                                                                                                                                                                                    • Case of Hysteretic Damping
                                                                                                                                                                                                                                                                                                                                                                                      • 4432 Peak-Picking Method
                                                                                                                                                                                                                                                                                                                                                                                        • 444 Multi-Degree of Freedom Curve Fitting
                                                                                                                                                                                                                                                                                                                                                                                          • 4441 Formulation of the Method
                                                                                                                                                                                                                                                                                                                                                                                            • 445 A Comment on Static Modes and Rigid-Body Modes
                                                                                                                                                                                                                                                                                                                                                                                            • 446 Residue Extraction
                                                                                                                                                                                                                                                                                                                                                                                              • 45 Laboratory Experiments
                                                                                                                                                                                                                                                                                                                                                                                                • 451 Lumped-Parameter System
                                                                                                                                                                                                                                                                                                                                                                                                  • 4511 Frequency-Domain Test
                                                                                                                                                                                                                                                                                                                                                                                                  • 4512 Time-Domain Tests
                                                                                                                                                                                                                                                                                                                                                                                                    • 452 Distributed-Parameter System
                                                                                                                                                                                                                                                                                                                                                                                                      • 46 Commercial EMA Systems
                                                                                                                                                                                                                                                                                                                                                                                                        • 461 System Configuration
                                                                                                                                                                                                                                                                                                                                                                                                          • 4611 FFT Analysis Options
                                                                                                                                                                                                                                                                                                                                                                                                          • 4612 Modal Analysis Components
                                                                                                                                                                                                                                                                                                                                                                                                              • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                  • 53191ch5
                                                                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                    • Chapter 5 Mechanical Shock
                                                                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                      • 51 Definitions
                                                                                                                                                                                                                                                                                                                                                                                                                        • 511 Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 512 Simple (or Perfect) Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 513 Half-Sine Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 514 Versed-Sine (or Haversine) Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 515 Terminal Peak Sawtooth Shock or Final Peak Sawtooth Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 516 Rectangular Shock
                                                                                                                                                                                                                                                                                                                                                                                                                          • 5161 Trapezoidal Shock
                                                                                                                                                                                                                                                                                                                                                                                                                              • 52 Description in the Time Domain
                                                                                                                                                                                                                                                                                                                                                                                                                              • 53 Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                • 531 Need
                                                                                                                                                                                                                                                                                                                                                                                                                                • 532 Shock Response Spectrum Definition
                                                                                                                                                                                                                                                                                                                                                                                                                                • 533 Response of a Linear One-Degree-of-Freedom System
                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5331 Shock Defined by a Force
                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5332 Shock Defined by an Acceleration
                                                                                                                                                                                                                                                                                                                                                                                                                                    • 534 Definitions
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5341 Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5342 Absolute Acceleration Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5343 Relative Displacement Shock Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5344 Primary Positive Shock Response Spectrum or Initial Positive Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5345 Primary (or Initial) Negative Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5346 Secondary (or Residual) Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5347 Positive (or Maximum Positive) Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5348 Negative (or Maximum Negative) Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5349 Maximax Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53410 Choice of Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                        • 535 Standardized Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5351 Definition
                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5352 Standardized Shock Response Spectra of Simple Shocks
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53521 Half-Sine Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53522 Versed Sine Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53523 Terminal Peak Sawtooth Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53524 Rectangular Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53525 Trapezoidal Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 536 Choice of Damping
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 537 Shock Response Spectra Domains
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 538 Algorithms for Calculation of the Shock Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 539 Choice of the Digitization Frequency of the Signal
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5310 Use of Shock Response Spectra for the Study of Systems with Several Degrees of Freedom
                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 54 Pyroshocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 55 Use of Shock Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 551 Severity Comparison of Several Shocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 552 Test Specification Development from Real Environment Data
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5521 Synthesis of Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5522 Nature of the Specification
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5523 Choice of Shape
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5524 Amplitude
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5525 Duration
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5526 Difficulties
                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 56 Standards
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 561 Types of Standards
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 562 Installation Conditions of Test Item
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 563 Uncertainty Factor
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 564 Bump Test
                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 57 Damage Boundary Curve
                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 571 Definition
                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 572 Analysis of Test Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 58 Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 581 Main Types
                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 582 Impact Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5821 Universal Shock-Test Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 58211 Impact Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 58212 Impulse Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 583 Shock Simulators (Programmers)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5831 Half-Sine Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58311 Shock Duration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58312 Impact Velocity
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58313 Maximum Deformation of the Shock Simulator (Programmer)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58314 Shock Amplitude
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58315 Characteristics of the Target
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5832 Terminal Peak Sawtooth Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5833 Rectangular Pulse ndash Trapezoidal Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5834 Universal Shock Simulator (Programmer)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 58341 Generating a Half-Sine Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 58342 Generating a Terminal Peak Sawtooth Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 58343 Trapezoidal Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 584 Limitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5841 Limitations of the Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5842 Limitations of Shock Simulators
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 585 Pneumatic Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 586 High Impact Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5861 Lightweight High Impact Shock Machine
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5862 Medium Weight High Impact Shock Machine
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 587 Specific Test Facilities
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 59 Generation of Shock Using Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 591 Principle Behind the Generation of a Simple Shape Signal versus Time
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 592 Main Advantages
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 593 Pre- and Postshocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5931 Requirements
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5932 Solutions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 59321 Optimized Pre- and Postpulses
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5933 Incidence on the Shock Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 594 Limitations of Electrodynamic Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5941 Mechanical Limitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 59411 Abacuses
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5942 Electronic Limitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 595 The Use of Electrohydraulic Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 510 Control by a Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 5101 Principle
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 5102 Principal Shapes of Elementary Signals
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 51021 Decaying Sinusoid
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 51022 ZERD Function
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 51023 WAVSIN Waveform
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 5103 Comparison of WAVSIN SHOC Waveforms and Decaying Sinusoid
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 5104 Criticism of Control by a Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 511 Pyrotechnic Shock Simulation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5111 Simulation Using Pyrotechnic Facilities
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5112 Simulation Using Metal-to-Metal Impact
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5113 Simulation Using Electrodynamic Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5114 Simulation Using Conventional Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53191ch6
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Chapter 6 Machine Condition Monitoring and Fault Diagnostics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 61 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 62 Machinery Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 621 Causes of Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 622 Types of Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 623 Frequency of Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 63 Basic Maintenance Strategies
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 631 Run-to-Failure (Breakdown) Maintenance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 632 Scheduled (Preventative) Maintenance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 633 Condition-Based (Predictive Proactive Reliability Centered On-Condition) Maintenance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 64 Factors Which Influence Maintenance Strategy
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 65 Machine Condition Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 651 Periodic Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 652 Continuous Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 66 Transducer Selection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 661 Noncontact Displacement Transducers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 662 Velocity Transducers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 663 Acceleration Transducers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 67 Transducer Location
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 68 Recording and Analysis Instrumentation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 681 Vibration Meters
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 682 Data Collectors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 683 Frequency-Domain Analyzers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 684 Time-Domain Instruments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 685 Tracking Analyzers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 69 Display Formats and Analysis Tools
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 691 Time Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6911 Time-Waveform Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6912 Time-Waveform Indices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6913 Time-Synchronous Averaging
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6914 Negative Averaging
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6915 Orbits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6916 Probability Density Functions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6917 Probability Density Moments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 692 Frequency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6921 Band-Pass Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6922 Shock Pulse (Spike Energy)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6923 Enveloped Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6924 Signature Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6925 Cascades (Waterfall Plots)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6926 Masks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6927 Frequency-Domain Indices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 693 Modal Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 694 Quefrency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 610 Fault Detection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 6101 Standards
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61011 Standards Based on Machinery Type
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61012 Standards Based on Vibration Severity
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 6102 Acceptance Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 61021 Statistical Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 6103 Frequency-Domain Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61031 Limited Band Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61032 Constant Bandwidth Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61033 Constant Percentage Bandwidth Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 611 Fault Diagnostics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 6111 Forcing Functions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61111 Unbalance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61112 Misalignment
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61113 Mechanical Looseness
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61114 Soft Foot
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61115 Rubs
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61116 Resonances
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61117 Oil Whirl
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61118 Oil Whip
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61119 Structural Vibrations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 611110 Foundation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 6112 Specific Machine Components
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 61121 Damaged or Worn Rolling-Element Bearings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 61122 Damaged or Worn Gears
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 6113 Specific Machine Types
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61131 Pumps
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61132 Fans
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61133 Electric Motors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61134 Steam and Gas Turbines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61135 Compressors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61136 Reciprocating Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 6114 Advanced Fault Diagnostic Techniques
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 53191ch7
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • Chapter 7 Vibration-Based Tool Condition Monitoring Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 71 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 72 Mechanics of Turning
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 721 General Terms
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 722 Chatter Vibrations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 723 Tool Wear
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7231 Tool Failure Mechanisms
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7232 Tool Failure Modes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7233 Tool Wear Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7234 Tool Wear Stages
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 73 Vibration Signal Recording
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 731 Direct and Indirect Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 732 Sensor Requirements for Tool Wear Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 733 Force Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7331 Direct Measurement Dynamometers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7332 Indirect Force Sensors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7333 Piezoelectric Strain Sensors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7334 Resistance Strain Gauges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7335 Customized Force Sensors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 734 Acceleration Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 735 Acoustic Emission Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 736 Sensor Comparisons
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 74 Signal Processing for Sensor-Based Tool Condition Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 741 Feature Extraction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7411 Time Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7412 Frequency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7413 Statistical Processing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7414 TimendashFrequency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 742 Feature Selection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 75 Wear ModelDecision-Making for Sensor-Based Tool Condition Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 751 Trending Threshold
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 752 Neural Networks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7521 Unsupervised Networks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7522 Supervised Networks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 753 Fuzzy Logic
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 754 Other Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 76 Conclusion
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53191ch8
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Chapter 8 Fault Diagnosis of Helicopter Gearboxes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 81 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 82 Abnormality Scaling
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 83 The Structure-Based Connectionist Network
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 84 Sensor Location Selection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 841 Coverage Index
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 842 Overlap Index
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 843 Monitoring Effectiveness
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 85 A Case Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 851 Structural and Featural Influences
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 852 Evaluation of Influences
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 853 Fault Detection Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 854 Fault Diagnostic Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 8541 Faulty Subsystem Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 8542 Faulty Component Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 855 Sensor Location Evaluation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 856 Sensor Location Validation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 86 Conclusion
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 53191ch9
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Chapter 9 Vibration Suppression and Monitoring in Precision Motion Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 91 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 92 Mechanical Design to Minimize Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 921 Stability and Static Determinacy of Machine Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 922 Two-Dimensional Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 923 Three-Dimensional Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 93 Adaptive Notch Filter
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 931 Fast Fourier Transform
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 932 Simulation and Experiments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 94 Real-Time Vibration Analyzer
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 941 Learning Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 942 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 943 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 944 Experiments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 9441 Input Variables mdash the Evaluation Criteria
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 94411 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 94412 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 9442 Evaluation Rules
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 94421 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 94422 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 9443 Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 94431 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 94432 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 95 Practical Insights and Case Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 96 Conclusions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 53191ch10
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Chapter 10 Vibration and Shock Problems of Civil Engineering Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 101 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 102 Earthquake-Induced Vibration of Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1021 Seismicity and Ground Motions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1022 Influence of Local Site Conditions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1023 Response of Structures to Ground Motions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1024 Dynamic Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10241 Equations of Motion for Linear Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10242 Equations of Motion for Linear Multiple-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1025 Earthquake Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10251 Elastic Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10252 Smoothed Design Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10253 Ductility-Modified Response Spectrum Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1026 Design Philosophy and the Code Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10261 Performance-Based Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1027 Analysis Options for Earthquake Effects
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10271 Dynamic Time History Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10272 Response Spectrum Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 102721 Response Spectrum Analysis of Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 102722 Response Spectrum Analysis of Multi-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10273 Equivalent Static Analysis (Force-Based Approach)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10274 Displacement-Based Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1028 SoilndashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1029 Active and Passive Control Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 10210 Worked Examples
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 103 Dynamic Effects of Wind Loading on Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1031 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1032 Wind Speed
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1033 Design Structures for Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10331 Types of Wind Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10332 Design Criteria
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10333 Static Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1034 Along and Across-Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10341 Along-Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10342 Across-Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1035 Wind Tunnel Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1036 Comfort Criteria Human Response to Building Motion
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1037 Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1038 Comparison with Earthquake Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 104 Vibrations Due to Fluid ndashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1041 Added Mass and Inertial Coupling
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1042 Wave-Induced Vibration of Structure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 105 Blast Loading and Blast Effects on Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1051 Explosions and Blast Phenomenon
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1052 Explosive Air-Blast Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10521 Blast Wave Scaling Laws
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10522 Prediction of Blast Pressure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1053 Gas Explosion Loading and Effect of Internal Explosions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1054 Structural Response to Blast Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10541 Elastic Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10542 Elasto-Plastic Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1055 Material Behaviors at High Strain Rate
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10551 Dynamic Properties of Concrete under High Strain Rates
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10552 Dynamic Properties of Reinforcing Steel under High Strain Rates
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1056 Failure Modes of Blast-Loaded Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10561 Global Structural Behavior
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10562 Localized Structural Behavior
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10563 PressurendashImpulse ( PndashI ) Diagrams
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1057 Blast WavendashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1058 Effect of Ground Shocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10581 Loads from Air-Induced Ground Shock
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10582 Loads from Direct Ground Shock
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1059 Technical Design Manuals for Blast-Resistant Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 10510 Computer Programs for Blast and Shock Effects
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 106 Impact Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1061 Structural Impact between Two Bodies mdash Hard Impact and Soft Impact
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1062 Example mdash Aircraft Impact
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 107 Floor Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1071 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1072 Types of Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10721 Walking
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10722 Rhythmic Activities
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10723 Mechanical Equipment
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10724 Analysis Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1073 Natural Frequency of Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10731 Computing the Natural Frequency
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10732 Computing Deflection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10733 Damping
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10734 Resonance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1074 Vibration Caused by Walking
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10741 Minimum Natural Frequency
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1075 Design for Rhythmic Excitation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10751 Harmonics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10752 Minimum Natural Frequency
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1076 Example mdash Vibration Analysis of a Reinforced Concrete Floor
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 53191ch11
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Chapter 11 Seismic Base Isolation and Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 111 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1111 From Ductility Design to Base Isolation and Control Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1112 The Importance of Reducing Seismic Input and Response
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 112 Seismic Base Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1121 Historical Development of Base Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1122 Basic Principle
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1123 Issues in Seismic Base Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11231 Performance Criteria
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11232 Type of Structure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11233 Site Characteristics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11234 Retrofit Issues
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11235 Design of Building Services
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11236 Expected Life of Isolator
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1124 Seismic Isolation Devices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11241 Laminated Rubber Bearings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11242 Lead Rubber Bearing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11243 Friction-Based Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11244 Other Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1125 Design of Isolation Devices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11251 High-Damping Rubber Bearing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112511 Stability against Buckling
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112512 Stability against Roll Out
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11252 Lead Rubber Bearings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112521 Design of Lead Plug
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112522 Design of Laminated Rubber Bearing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11253 Design of Friction Pendulum System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1126 Verification of Properties of Isolation Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11261 Tests for Isolation Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 112611 System Characterization Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 112612 Prototype Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 112613 Quality Control Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11262 Uniform Building Code Recommendations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112621 Units Dependent on Loading Rates
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112622 Units Dependent on Bilateral Load
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112623 System Adequacy
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1127 Analysis of Base-Isolated Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11271 Modeling of a Superstructure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11272 Modeling of Isolation System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11273 Static Analysis Procedure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11274 Dynamic Analysis Procedure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 112741 Response Spectrum Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 112742 Time-History Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11275 Software for Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1128 Experimental Methods for Isolated Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1129 Implementation of Seismic Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11291 New Construction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112911 Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112912 Bridges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11292 Seismic Retrofit
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112921 Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112922 Bridges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11293 Other Implementations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 11210 Performance during Past Earthquakes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 112101 Performance of Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 112102 Performance of Bridges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 113 Seismic Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1131 Historical Development of Seismic Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1132 Basic Principles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11321 Passive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11322 Active Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11323 Semiactive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11324 Hybrid Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11325 Categorization of Basic Principles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1133 Important Issues in Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11331 SoilndashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11332 DevicendashStructure Interaction and Time Delay
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11333 Design Guidelines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1134 Vibration-Control Devices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11341 Passive Control Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113411 Metallic Yielding Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113412 Friction Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113413 Viscoelastic Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113414 Viscous Fluid Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113415 Tuned Mass Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11342 Active Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113421 Electromagnetic Actuator
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113422 Hydraulic Actuators
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11343 Semiactive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113431 Variable-Orifice Hydraulic Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113432 Controllable Fluid Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113433 Controllable Friction Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11344 Hybrid Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1135 Control Algorithm
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11351 Active Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11352 Semiactive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113521 Common Control Schemes for Controllable Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113522 Special Control Schemes for Controllable Damper
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1136 Experimental Performance Verification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11361 Shaking Table Tests of a Flexible Structural Model with TMD AMD and ATMD
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11362 Substructure Hybrid Test
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113621 Hybrid Tests Using Hydraulic Actuator
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113622 Hybrid Tests Using Shaking Table
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113623 Hybrid Tests Using Inertia-Force-Driven Loading System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1137 Implementations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11371 Semiactive Control of Full-Scale Structures Using Variable Joint Damper System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113711 Background of Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113712 Test System Set Up
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113713 Control Algorithm
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113714 Test Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11372 Application of Structural Control Technologies to Seismic Retrofit of a Cable-Stayed Bridge
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113721 Background of Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113722 Basic Concept of Seismic Retrofit
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113723 Modal Shape Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113724 Time-History Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113725 Soil ndash Structure Interaction Effect
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113726 Semiactive Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53191ch12
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Chapter 12 Seismic Random Vibration of Long-Span Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 121 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1211 Basic Concepts of Random Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12111 Stationary Random Process
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12112 Nonstationary Random Process
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1212 Three Methods for Structural Seismic Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12121 Response Spectrum Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12122 Time-History Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12123 Random Vibration Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 121231 Davenport Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 121232 Vanmarcke Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 12124 Comparisons of the Three Seismic-Analysis Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 122 Seismic Random-Excitation Fields
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1221 Power Spectral Density of Spatially Varying Ground Acceleration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1222 Several Coherence Models
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12221 FengndashHu Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12222 Harichandran ndashVanmarcke Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12223 LohndashYeh Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12224 OliveirandashHaondashPenzien Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12225 LucondashWong Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12226 QundashWangndashWang Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1223 Generation of Ground Acceleration Power Spectral Density Curves from Acceleration Response Spectrum Curves
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12231 Kaul Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12232 Iteration Scheme
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1224 Seismic Equations of Motion of Long-Span Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1225 Seismic Waves and Their Geometrical Expressions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 123 Pseudoexcitation Method for Structural Random Vibration Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1231 Structures Subjected to Stationary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12311 Single Stationary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12312 Multiple Stationary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1232 Structures Subjected to Nonstationary Random Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12321 Structures Subjected to Uniformly Modulated Evolutionary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 123211 Single Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 123212 Multiple Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12322 Structures Subjected to Nonuniformly Modulated Evolutionary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 123221 Single Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 123222 Multiple Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1233 Precise Integration Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12331 Precise Integration of Exponential Matrices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12332 Particular Solutions and Precise Integration Formulas for Various Forms of Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 123321 Linear Loading Form (HPD-L Form)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 123322 Sinusoidal Loading Form (HPD-S Form)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 123323 Exponentially Decaying Sinusoidal Loading Form (HPD-E Form)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 124 Long-Span Structures Subjected to Stationary Random Ground Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1241 The Solution of Equations of Motion Using the Pseudoexcitation Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1242 Numerical Comparisons with Other Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12421 Song-Hua-Jiang Suspension Bridge
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 124211 All Supports Move Uniformly
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 124212 Wave Passage Effect Is Taken into Account
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 124213 Wave-Passage Effect and Incoherence Effect Are Jointly Taken into Account
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 12422 San Joaquin Concrete Bridge
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 125 Long-Span Structures Subjected to Nonstationary Random Ground Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1251 Modulation Functions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1252 The Formulas for Nonstationary Multiexcitation Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1253 Expected Extreme Values of Nonstationary Random Processes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1254 Numerical Comparisons with the Corresponding Stationary Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 126 Conclusions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 53191ch13
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Chapter 13 Seismic Qualification of Equipment
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 131 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 132 Distribution Qualification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1321 Drive-Signal Generation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1322 Distribution Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1323 Test Procedures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 133 Seismic Qualification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1331 Stages of Seismic Qualification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1332 Test Preliminaries
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1333 Single-Frequency Testing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1334 Multifrequency Testing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1335 Generation of RRS Specifications
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 53191ch14
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Chapter 14 Human Response to Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 141 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 142 Vibration Excitations on Humans
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1421 Excitation Characteristics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 143 Human Response to Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1431 Vibration Perception
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1432 Frequency Weighting Curve
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1433 Iso-Perception Curves
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1434 Detection Threshold Curve
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 144 Regulation of Human Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1441 Acceptable Vibration Levels in Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1442 Whole-Body Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1443 HandndashArm Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
Page 11: Vibration Monitoring, Testing, and Instrumentationpreview.kingborn.net › 646000 › d1a74678d91943e5ba1d5e... · The MEMS Handbook, Second Edition MEMS: Introduction and Fundamentals

5 Mechanical Shock Christian Lalanne 5-1

51 Definitions 5-2

52 Description in the Time Domain 5-3

53 Shock Response Spectrum 5-4

54 Pyroshocks 5-17

55 Use of Shock Response Spectra 5-18

56 Standards 5-24

57 Damage Boundary Curve 5-26

58 Shock Machines 5-28

59 Generation of Shock Using Shakers 5-44

510 Control by a Shock Response Spectrum 5-52

511 Pyrotechnic Shock Simulation 5-58

6 Machine Condition Monitoring and Fault Diagnostics Chris K Mechefske 6-1

61 Introduction 6-2

62 Machinery Failure 6-2

63 Basic Maintenance Strategies 6-4

64 Factors Which Influence Maintenance Strategy 6-7

65 Machine Condition Monitoring 6-8

66 Transducer Selection 6-10

67 Transducer Location 6-14

68 Recording and Analysis Instrumentation 6-14

69 Display Formats and Analysis Tools 6-16

610 Fault Detection 6-21

611 Fault Diagnostics 6-25

7 Vibration-Based Tool Condition Monitoring Systems C Scheffer and PS Heyns 7-1

71 Introduction 7-1

72 Mechanics of Turning 7-2

73 Vibration Signal Recording 7-7

74 Signal Processing for Sensor-Based Tool Condition Monitoring 7-11

75 Wear ModelDecision-Making for Sensor-Based Tool Condition Monitoring 7-15

76 Conclusion 7-20

8 Fault Diagnosis of Helicopter Gearboxes Kourosh Danai 8-1

81 Introduction 8-1

82 Abnormality Scaling 8-5

83 The Structure-Based Connectionist Network 8-8

84 Sensor Location Selection 8-11

85 A Case Study 8-14

86 Conclusion 8-23

9 Vibration Suppression and Monitoring in Precision Motion Systems KK Tan

TH Lee KZ Tang S Huang SY Lim W Lin and YP Leow 9-1

91 Introduction 9-1

92 Mechanical Design to Minimize Vibration 9-2

93 Adaptive Notch Filter 9-10

94 Real-Time Vibration Analyzer 9-17

Contentsxiv

53191mdash1432007mdash1850mdashVELUmdash246493mdash CRC ndash pp 1ndash15

copy 2007 by Taylor amp Francis Group LLC

95 Practical Insights and Case Study 9-29

96 Conclusions 9-35

10 Vibration and Shock Problems of Civil Engineering Structures Priyan Mendis

and Tuan Ngo 10-1

101 Introduction 10-2

102 Earthquake-Induced Vibration of Structures 10-3

103 Dynamic Effects of Wind Loading on Structures 10-22

104 Vibrations Due to FluidndashStructure Interaction 10-33

105 Blast Loading and Blast Effects on Structures 10-34

106 Impact Loading 10-47

107 Floor Vibration 10-51

11 Seismic Base Isolation and Vibration Control Hirokazu Iemura Sarvesh Kumar Jain

and Mulyo Harris Pradono 11-1

111 Introduction 11-1

112 Seismic Base Isolation 11-4

113 Seismic Vibration Control 11-33

12 Seismic Random Vibration of Long-Span Structures Jiahao Lin and Yahui Zhang 12-1

121 Introduction 12-2

122 Seismic Random-Excitation Fields 12-11

123 Pseudoexcitation Method for Structural Random Vibration Analysis 12-16

124 Long-Span Structures Subjected to Stationary Random Ground Excitations 12-27

125 Long-Span Structures Subjected to Nonstationary Random Ground Excitations 12-34

126 Conclusions 12-39

13 Seismic Qualification of Equipment Clarence W de Silva 13-1

131 Introduction 13-1

132 Distribution Qualification 13-1

133 Seismic Qualification 13-6

14 Human Response to Vibration Clarence W de Silva 14-1

141 Introduction 14-1

142 Vibration Excitations on Humans 14-2

143 Human Response to Vibration 14-3

144 Regulation of Human Vibration 14-6

Contents xv

53191mdash1432007mdash1850mdashVELUmdash246493mdash CRC ndash pp 1ndash15

copy 2007 by Taylor amp Francis Group LLC

1Vibration

Instrumentation

Clarence W de SilvaThe University of British Columbia

11 Introduction 1-1

12 Vibration Exciters 1-3Shaker Selection dagger Dynamics of Electromagnetic Shakers

13 Control System 1-15Components of a Shaker Controller dagger Signal-Generating

Equipment

14 Performance Specification 1-21Parameters for Performance Specification dagger Linearity dagger

Instrument Ratings dagger Accuracy and Precision

15 Motion Sensors and Transducers 1-27Potentiometer dagger Variable-Inductance Transducers dagger

Mutual-Induction Proximity Sensor dagger Selfinduction

Transducers dagger Permanent-Magnet Transducers dagger

Alternating Current Permanent-Magnet Tachometer dagger

Alternating Current Induction Tachometer dagger Eddy Current

Transducers dagger Variable-Capacitance Transducers dagger

Piezoelectric Transducers

16 Torque Force and Other Sensors 1-50Strain Gage Sensors dagger Miscellaneous Sensors

Appendix 1A Virtual Instrumentation for DataAcquisition Analysis and Presentation 1-73

Summary

Devices useful in instrumenting a mechanical vibrating system are presented in this chapter Shakers whichgenerate vibration excitations are discussed and compared A variety of sensors including motion sensorsproximity sensors forcetorque sensors and other miscellaneous sensors are considered Performance specificationin the time domain and the frequency domain is addressed Rating parameters of instruments are given

11 Introduction

Measurement and associated experimental techniques play a significant role in the practice of vibration

Academic exposure to vibration instrumentation usually arises in laboratories in the context of learning

training and research In vibration practice perhaps the most important task of instrumentation is the

measurement or sensing of vibration Vibration sensing is useful in the following applications

1 Design and development of a product

2 Testing (screening) of a finished product for quality assurance

3 Qualification of a good-quality product to determine its suitability for a specific application

1-1

53191mdash522007mdash1201mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

4 Mechanical aging of a product prior to carrying out a test program

5 Exploratory testing of a product to determine its dynamic characteristics such as resonances

mode shapes and even a complete dynamic model

6 Vibration monitoring for performance evaluation

7 Control and suppression of vibration

Figure 11 indicates a procedure typical of experimental vibration highlighting the essential

instrumentation Vibrations are generated in a device the test object in response to some excitation In

some experimental procedures primarily in vibration testing (see Figure 11) the excitation signal has

to be generated in a signal generator in accordance with some requirement (specification) and applied to

the object through an exciter after amplification and conditioning In some other situations primarily in

performance monitoring and vibration control the excitations are generated as an integral part of the

operating environment of the vibrating object and may originate either within the object (eg engine

excitations in an automobile) or in the environment with which the object interacts during operation

(eg road disturbances on an automobile) Sensors are needed to measure vibrations in the test object In

particular a control sensor is used to check whether the specified excitation is applied to the object

and one or more response sensors may be used to measure the resulting vibrations at key locations of

the object

The sensor signals have to be properly conditioned for example by filtering and amplification and

modified for example through modulation demodulation and analog-to-digital conversion prior to

recording analyzing and display The purpose of the controller is to guarantee that the excitation is

correctly applied to the test object If the signal from the control sensor deviates from the required

excitation the controller modifies the signal to the exciter so as to reduce this deviation Furthermore the

controller will stabilize or limit (compress) the vibrations in the object It follows that instruments in

experimental vibration may be generally classified into the following categories

1 Signal-generating devices

2 Vibration exciters

3 Sensors and transducers

4 Signal conditioningmodifying devices

5 Signal analysis devices

6 Control devices

7 Vibration recording and display devices

AnalogDigital

Interface

DigitalSignal

RecorderAnalyzerDisplay

FilterAmplifier

FilterAmplifier

SignalGenerator

and ExciterController

Reference (Required)Signal (Specification)

PowerAmplifier

MountingFixtures

TestObject

ResponseSensor

ControlSensor

Exciter

SwivelBase

FIGURE 11 Typical instrumentation in experimental vibration

Vibration Monitoring Testing and Instrumentation1-2

53191mdash522007mdash1201mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

Note that one instrument may perform the tasks

of more than one category listed here Also more

than one instrument may be needed to carry out

tasks in a single category In the following sections

we will provide some examples of the types of

vibration instrumentation giving characteristics

operating principles and important practical

considerations Also we will describe several

experiments which can be found in a typical

vibration laboratory

An experimental vibration system generally

consists of four main subsystems

1 Test object

2 Excitation system

3 Control system

4 Signal acquisition and modification system

These are schematically shown in Figure 12 Note that various components shown in Figure 11 may

be incorporated into one of these subsystems In particular component matching hardware and object

mounting fixtures may be considered interfacing devices that are introduced through the interaction

between the main subsystems as shown in Figure 12 Some important issues of vibration testing and

instrumentation are summarized in Box 11

12 Vibration Exciters

Vibration experimentation may require an external exciter to generate the necessary vibration This is the

case in controlled experiments such as product testing where a specified level of vibration is applied to the

test object and the resulting response is monitored A variety of vibration exciters are available with

different capabilities and principles of operation

Three basic types of vibration exciters (shakers) are widely used hydraulic shakers inertial shakers

and electromagnetic shakers The operation-capability ranges of typical exciters in these three categories

are summarized in Table 11 Stroke or maximum displacement is the largest displacement the exciter

is capable of imparting onto a test object whose weight is assumed to be within its design load limit

Maximum velocity and acceleration are similarly defined Maximum force is the largest force that could

be applied by the shaker to a test object of acceptable weight (one within the design load) The values

given in Table 11 should be interpreted with caution Maximum displacement is achieved only at very

low frequencies The achievement of maximum velocity corresponds to intermediate frequencies in the

operating frequency range of the shaker Maximum acceleration and force ratings are usually achieved at

high frequencies It is not feasible for example to operate a vibration exciter at its maximum

displacement and its maximum acceleration simultaneously

Consider a loaded exciter that is executing harmonic motion Its displacement is given by

x frac14 s sin vt eth11THORN

in which s is the displacement amplitude (or stroke) Corresponding velocity and acceleration are

_x frac14 sv cos vt eth12THORN

eurox frac14 2sv2sin vt eth13THORN

SignalModification

System

TestObject

ControlSystem

VibrationExciter (Shaker)

System

FIGURE 12 Interactions between major subsystems of

an experimental vibration system

Vibration Instrumentation 1-3

53191mdash522007mdash1201mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

If the velocity amplitude is denoted by v and the acceleration amplitude by a it follows from Equation

12 and Equation 13 thatv frac14 vs eth14THORN

and

a frac14 vv eth15THORN

Box 11

VIBRATION INSTRUMENTATION

Vibration Testing Applications for Products

Design and Development Production Screening and Quality Assessment Utilization and Qualification for Special Applications

Testing Instrumentation

Exciter (excites the test object) Controller (controls the exciter for accurate excitation) Sensors and Transducers (measure excitations and responses and provide excitation error

signals to controller) Signal Conditioning (converts signals to appropriate form) Recording and Display (perform processing storage and documentation)

Exciters

Shakers

1 Electrodynamic (high bandwidth moderate power complex and multifrequency

excitations)

2 Hydraulic (moderate to high bandwidth high power complex and multifrequency

excitations)

3 Inertial (low bandwidth low power single-frequency harmonic excitations)

TransientInitial Condition

1 Hammers (impulsive bump tests)

2 Cable Release (step excitations)

3 Drop (impulsive)

Signal Conditioning

Filters Amplifiers Amplifiers ModulatorsDemodulators ADCDAC

Sensors

Motion (displacement velocity acceleration) Force (strain torque)

Vibration Monitoring Testing and Instrumentation1-4

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copy 2007 by Taylor amp Francis Group LLC

TABLE 11 Typical Operation-Capability Ranges for Various Shaker Types

Shaker Type Typical Operational Capabilities

Frequency Maximum Displacement

(Stroke)

Maximum

Velocity

Maximum

Acceleration

Maximum

Force

Excitation

Waveform

Hydraulic

(electrohydraulic)

Low

(01ndash500 Hz)

High (20 in 50 cm) Intermediate

(50 insec

125 cmsec)

Intermediate

(20 g)

High (100000 lbf

450000 N)

Average flexibility (simple

to complex and random)

Inertial

(counter-rotating mass)

Intermediate

(2ndash50 Hz)

Low (1 in 25 cm) Intermediate

(50 insec

125 cmsec)

Intermediate

(20 g)

Intermediate

(1000 lbf 4500 N)

Sinusoidal only

Electromagnetic

(electrodynamic)

High

(2ndash10000 Hz)

Low (1 in 25 cm) Intermediate

(50 insec

125 cmsec)

High (100 g) Low to intermediate

(450 lbf 2000 N)

High flexibility and accuracy

(simple to complex and

random)

VibrationInstru

mentation

1-5

53191mdash522007mdash

1201mdashSENTHILKUMARmdash246494mdash

CRCndashpp1ndash112

copy 2007 by Taylor amp Francis Group LLC

An idealized performance curve of a shaker

has a constant displacementndashamplitude region a

constant velocityndashamplitude region and a con-

stant accelerationndashamplitude region for low

intermediate and high frequencies respectively

in the operating frequency range Such an ideal

performance curve is shown in Figure 13(a) on a

frequencyndashvelocity plane Logarithmic axes are

used In practice typical shaker performance

curves would be fairly smooth yet nonlinear

curves similar to those shown in Figure 13(b)

As the mass increases the performance curve

compresses Note that the acceleration limit of a

shaker depends on the mass of the test object

(load) Full load corresponds to the heaviest object

that could be tested The ldquono loadrdquo condition

corresponds to a shaker without a test object To

standardize the performance curves they are

usually defined at the rated load of the shaker A

performance curve in the frequencyndashvelocity

plane may be converted to a curve in the

frequencyndashacceleration plane simply by increasing

the slope of the curve by a unit magnitude (ie

20 dbdecade)

Several general observations can be made from

Equation 14 and Equation 15 In the constant-

peak displacement region of the performance

curve the peak velocity increases proportionally

with the excitation frequency and the peak

acceleration increases with the square of the excitation frequency In the constant-peak velocity region

the peak displacement varies inversely with the excitation frequency and the peak acceleration increases

proportionately In the constant-peak acceleration region the peak displacement varies inversely with the

square of the excitation frequency and the peak velocity varies inversely with the excitation frequency

This further explains why rated stroke maximum velocity and maximum acceleration values are not

simultaneously realized

121 Shaker Selection

Vibration testing is accomplished by applying a specified excitation to the test package using a shaker

apparatus and monitoring the response of the test object Test excitation may be represented by its

response spectrum The test requires that the response spectrum of the actual excitation known as the

test response spectrum (TRS) envelops the response spectrum specified for the particular test known as

the required response spectrum (RRS)

A major step in the planning of any vibration testing program is the selection of a proper shaker

(exciter) system for a given test package The three specifications that are of primary importance in

selecting a shaker are the force rating the power rating and the stroke (maximum displacement) rating

Force and power ratings are particularly useful in moderate to high frequency excitations and the stroke

rating is the determining factor for low frequency excitations In this section a procedure is given to

determine conservative estimates for these parameters in a specified test for a given test package

Frequency domain considerations are used here

Stroke

Limit M

ax

Acceleration

MaxVelocity

Peak

Vel

ocity

(cm

s)

01 1 10 100

FullLoad

NoLoad

Frequency (Hz)(a)

Peak

Vel

ocity

(cm

s)

100

10

1

100

10

1

01 1 10 100

FullLoad

NoLoad

Frequency (Hz)(b)

FIGURE 13 Performance curve of a vibration exciter

in the frequencyndashvelocity plane (log) (a) ideal (b)

typical

Vibration Monitoring Testing and Instrumentation1-6

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copy 2007 by Taylor amp Francis Group LLC

1211 Force Rating

In the frequency domain the (complex) force at the exciter (shaker) head is given by

F frac14 mHethvTHORNasethvTHORN eth16THORNin which v is the excitation frequency variable m is the total mass of the test package including

mounting fixture and attachments asethvTHORN is the Fourier spectrum of the support-location (exciter head)

acceleration and H(v) is frequency response function that takes into account the flexibility and

damping effects (dynamics) of the test package apart from its inertia In the simplified case where the

test package can be represented by a simple oscillator of natural frequency vn and damping ratio by zt

this function becomes

HethvTHORN frac14 1thorn 2jztv=vn=12 ethv=vnTHORN2 thorn 2jztv=vn eth17THORNin which j frac14 ffiffiffiffi

21p

This approximation is adequate for most practical purposes The static weight of the

test object is not included in Equation 16 Most heavy-duty shakers which are typically hydraulic

have static load support systems such as pneumatic cushion arrangements that can exactly balance the

dead load The exciter provides only the dynamic force In cases where shaker directly supports the

gravity load in the vertical test configuration Equation 16 should be modified by adding a term to

represent this weight

A common practice in vibration test applications is to specify the excitation signal by its response

spectrum This is simply the peak response of a simple oscillator expressed as a function of its natural

frequency when its support location is excited by the specified signal Clearly the damping of the simple

oscillator is an added parameter in a response spectrum specification Typical damping ratios ethzrTHORN used inresponse spectra specifications are less than 01 (or 10) It follows that an approximate relationship

between the Fourier spectrum of the support acceleration and its response spectrum is

as frac14 2jzrarethvTHORN eth18THORNThe magnitude larethvTHORNl is the response spectrumEquation 18 substituted into Equation 16 gives

F frac14 mHethvTHORN2jzrarethvTHORN eth19THORNIn view of Equation 17 for test packages having low damping the peak value of H(v) is

approximately 1=eth2jztTHORN this should be used in computing the force rating if the test package has a

resonance within the frequency range of testing On the other hand if the test package is assumed to be

rigid then HethvTHORN oslash 1 A conservative estimate for the force rating is

Fmax frac14 methzr=ztTHORNlarethvTHORNlmax eth110THORNIt should be noted that larethvTHORNlmax is the peak value of the specified (required) response spectrum (RRS)

for acceleration

1212 Power Rating

The exciter head does not develop its maximum force when driven at maximum velocity Output power

is determined by using

p frac14 Refrac12FvsethvTHORN eth111THORNin which vsethvTHORN is the Fourier spectrum of the exciter velocity and Re [ ] denotes the real part of a complex

function Note that as frac14 jvvs Substituting Equation 16 and Equation 18 into Equation 111 gives

p frac14 eth4mz2r =vTHORNRefrac12jHethvTHORNa2r ethvTHORN eth112THORNIt follows that a conservative estimate for the power rating is

pmax frac14 2methz2r =ztTHORNfrac12larethvTHORNl2=v max eth113THORN

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Representative segments of typical acceleration RRS curves have slope n as given by

a frac14 k1vn eth114THORN

It should be clear from Equation 113 that the maximum output power is given by

pmax frac14 k2v2n21 eth115THORN

This is an increasing function for n 1=2 and a decreasing function for n 1=2 It follows that the power

rating corresponds to the highest point of contact between the acceleration RRS curve and a line of slope

equal to 12 A similar relationship may be derived if velocity RRS curves (having slopes n2 1) are used

1213 Stroke Rating

From Equation 18 it should be clear that the Fourier spectrum xs of the exciter displacement time

history can be expressed as

xs frac14 2zrarethvTHORN=jv2 eth116THORNAn estimate for stroke rating is

xmax frac14 2zrfrac12larethvTHORNl=v2 max eth117THORNThis is of the form

xmax frac14 kvn22 eth118THORNIt follows that the stroke rating corresponds to the highest point of contact between the acceleration

RRS curve and a line of slope equal to two

Example 11

A test package of overall mass 100 kg is to be

subjected to dynamic excitation represented by the

acceleration RRS (at 5 damping) as shown in

Figure 14 The estimated damping of the test

package is 7 The test package is known to have a

resonance within the frequency range of the

specified test Determine the exciter specifications

for the test

Solution

From the development presented in the previous

section it is clear that the point F (or P) in

Figure 14 corresponds to the force and output

power ratings and the point S corresponds to

the stroke rating The co-ordinates of these

critical points are F P frac14 eth42 Hz 40 gTHORN and S frac14 eth08 Hz 075 gTHORN Equation 110 gives the force

rating as

Fmax frac14 100 pound eth005=007THORN pound 40 pound 981 N frac14 2803 N

Equation 113 gives the power rating as

pmax frac14 2 pound 100 pound eth0052=007THORN pound frac12eth40 pound 981THORN2=42 pound 2p watts frac14 417 W

Equation 117 gives the stroke rating as

xmax frac14 2 pound 005 pound frac12eth075 pound 98THORN=eth08 pound 2pTHORN2 m frac14 3 cm

Acc

eler

atio

n(g

)

Con

stan

t Dis

plac

emen

t

Constant Velo

city

Frequency (Hz)

S

FP

0101

10 10 100

10

10

FIGURE 14 Test excitation specified by an accelera-

tion RRS (5 damping)

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1214 Hydraulic Shakers

A typical hydraulic shaker consists of a piston-cylinder arrangement (also called a ram) a servo-valve a

fluid pump and a driving electric motor Hydraulic fluid (oil) is pressurized (typical operating pressure

4000 psi) and pumped into the cylinder through a servo-valve by means of a pump that is driven by an

electric motor (typical power 150 hp) The flow (typical rate 100 galmin) that enters the cylinder is

controlled (modulated) by the servo-valve which in effect controls the resulting piston (ram) motion

A typical servo-valve consists of a two-stage spool valve which provides a pressure difference and a

controlled (modulated) flow to the piston which sets it in motion

The servo-valve itself is moved by means of a linear torque motor which is driven by the excitation-

input signal (electrical) A primary function of the servo-valve is to provide a stabilizing feedback to the

ram In this respect the servo-valve complements the main control system of the test setup The ram is

coupled to the shaker table by means of a link with some flexibility The cylinder frame is mounted on the

support foundation with swivel joints This allows for some angular and lateral misalignment which

might be caused primarily by test-object dynamics as the table moves

Two-degree-of-freedom (Two-DoF) testing requires two independent sets of actuators and three-DoF

testing requires three independent actuator sets Each independent actuator set can consist of several

actuators operated in parallel using the same pump and the same excitation-input signal to the torque

motors

If the test table is directly supported on the vertical actuators they must withstand the total dead

weight (ie the weight of the test table the test object the mounting fixtures and the instrumentation)

This is requirement is usually prevented by providing a pressurized air cushion in the gap between the

test table and the foundation walls Air should be pressurized so as to balance the total dead weight

exactly (typical required gage pressure 3 psi)

Figure 15(a) shows the basic components of a typical hydraulic shaker The corresponding

operational block diagram is shown in Figure 15(b) It is desirable to locate the actuators in a pit in the

test laboratory so that the test tabletop is flushed with the test laboratory floor under no-load conditions

This minimizes the effort required to place the test object on the test table Otherwise the test object has

to be lifted onto the test table with a forklift Also installation of an aircushion to support the system

dead weight is difficult under these circumstances of elevated mounting

Hydraulic actuators are most suitable for heavy load testing and are widely used in industrial and civil

engineering applications They canbeoperated at very low frequencies (almost direct current [DC]) aswell

as at intermediate frequencies (see Table 11) Large displacements (stroke) are possible at low frequencies

Hydraulic shakers have the advantage of providing high flexibility of operation during the test their

capabilities include variable-force and constant-force testing and wide-band random-input testing The

velocity and acceleration capabilities of hydraulic shakers are moderate Although any general excitation-

input motion (for example sine wave sine beat wide-band random) can be used in hydraulic shakers

faithful reproduction of these signals is virtually impossible at high frequencies because of distortion and

higher-order harmonics introduced by the high noise levels that are common in hydraulic systems This

is only a minor drawback in heavy-duty intermediate-frequency applications Dynamic interactions are

reduced through feedback control

1215 Inertial Shakers

In inertial shakers or ldquomechanical excitersrdquo the force that causes the shaker-table motion is generated by

inertia forces (accelerating masses) Counter-rotating-mass inertial shakers are typical in this category

To understand their principle of operation consider two equal masses rotating in opposite directions at

the same angular speed v and in the same circle of radius r (see Figure 16) This produces a resultant

force equal to 2mv2r cos vt in a fixed direction (the direction of symmetry of the two rotating arms)

Consequently a sinusoidal force with a frequency of v and an amplitude proportional to v2 is generated

This reaction force is applied to the shaker table

Figure 17 shows a sketch of a typical counter-rotating-mass inertial shaker It consists of two identical

rods rotating at the same speed in opposite directions Each rod has a series of slots in which to

Vibration Instrumentation 1-9

53191mdash522007mdash1201mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

place weights In this manner the magnitude of

the eccentric mass can be varied to achieve various

force capabilities The rods are driven by a

variable-speed electric motor through a gear

mechanism that usually provides several speed

ratios A speed ratio is selected depending on the

required test-frequency range The whole system is

symmetrically supported on a carriage that is

directly connected to the test table The test object

is mounted on the test table The preferred

mounting configuration is horizontal so that the

excitation force is applied to the test object in a

horizontal direction In this configuration there

are no variable gravity moments (weight pounddistance to center of gravity) acting on the drive

mechanism Figure 17 shows the vertical con-

figuration In dynamic testing of large structures

the carriage can be mounted directly on the

structure at a location where the excitation force

should be applied By incorporating two pairs of

counter-rotating masses it is possible to generate

test moments as well as test forces

FIGURE 15 A typical hydraulic shaker arrangement (a) schematic diagram (b) operational block diagram

m m

2mw2r cos wt

wtw w

wt

FIGURE 16 Principle of operation of a counter-

rotating-mass inertial shaker

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Reaction-type shakers driven by inertia are widely used for the prototype testing of civil engineering

structures Their first application dates back to 1935 Inertial shakers are capable of producing

intermediate excitation forces The force generated is limited by the strength of the carriage frame The

frequency range of operation and the maximum velocity and acceleration capabilities are also

intermediate for inertial shakers whereas the maximum displacement capability is typically low A major

limitation of inertial shakers is that their excitation force is exclusively sinusoidal and that the force

amplitude is directly proportional to the square of the excitation frequency As a result complex and

random excitation testing constant-force testing (for example transmissibility tests and constant-force

sine-sweep tests) and flexibility to vary the force amplitude or the displacement amplitude during a test

are not generally feasible with this type of shakers Excitation frequency and amplitude can be varied

during testing however by incorporating a variable-speed drive for the motor The sinusoidal excitation

generated by inertial shakers is virtually undistorted which gives them an advantage over the other types

of shakers when used in sine-dwell and sine-sweep tests Small portable shakers with low-force capability

are available for use in on-site testing

1216 Electromagnetic Shakers

In electromagnetic shakers or ldquoelectrodynamic excitersrdquo the motion is generated using the principle of

operation of an electric motor Specifically the excitation force is produced when a variable excitation

signal (electrical) is passed through a moving coil placed in a magnetic field

The components of a commercial electromagnetic shaker are shown in Figure 18 A steady magnetic

field is generated by a stationary electromagnet that consists of field coils wound on a ferromagnetic base

that is rigidly attached to a protective shell structure The shaker head has a coil wound around it When

the excitation electrical signal is passed through this drive coil the shaker head which is supported on

flexure mounts will be set in motion The shaker head consists of the test table on which the test object

is mounted Shakers with interchangeable heads are available The choice of appropriate shaker head is

based on the geometry and mounting features of the test object The shaker head can be turned to

different angles by means of a swivel joint In this manner different directions of excitation (in biaxial

and triaxial testing) can be obtained

FIGURE 17 Sketch of a counter-rotating-mass inertial shaker

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copy 2007 by Taylor amp Francis Group LLC

122 Dynamics of Electromagnetic Shakers

Consider a single axis electromagnetic shaker (Figure 18) with a test object having a single natural

frequency of importance within the test frequency range The dynamic interactions between the shaker

and the test object give rise to two significant natural frequencies (and correspondingly two significant

resonances) These appear as peaks in the frequency response curve of the test setup Furthermore the

natural frequency (resonance) of the test package alone causes a ldquotroughrdquo or depression (antiresonance)

in the frequency response curve of the overall test setup To explain this characteristic consider the

dynamic model shown in Figure 19 The following mechanical parameters are defined for

Figure 19(a) m k and b are the mass stiffness and equivalent viscous damping constant respectively

of the test package and me ke and be are the corresponding parameters of the exciter (shaker) Also in

the equivalent electrical circuit of the shaker head as shown in Figure 19(b) the following electrical

parameters are defined Re and Le are the resistance and (leakage) inductance and kb is the back

electromotive force (back emf) of the linear motor Assuming that the gravitational forces are supported

FIGURE 18 Schematic sectional view of a typical electromagnetic shaker manufactured by Bruel and Kjaer

Denmark

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copy 2007 by Taylor amp Francis Group LLC

by the static deflections of the flexible elements and that the displacements are measured from the static

equilibrium position we have the following system equations

Test object meuroy frac14 2kethy2 yeTHORN2 beth_y2 _yeTHORN eth119THORNShaker head me euroye frac14 fe thorn kethy2 yeTHORN thorn beth_y2 _yeTHORN2 key 2 be _ye eth120THORN

Electrical Lediedt

thorn Reie thorn kb _ye frac14 vethtTHORN eth121THORN

The electromagnetic force fe generated in the shaker head is a result of the interaction of the magnetic

field generated by the current ie with coil of the moving shaker head and the constant magnetic field

(stator) in which the head coil is located Here we have

fe frac14 kbie eth122THORNNote that v(t) is the voltage signal that is applied by the amplifier to the shaker coil ye is the displacement

of the shaker head and y is the displacement response of the test package

It is assumed that kb has consistent electrical and mechanical units (Vmsec and NA) Usually

the electrical time constant of the shaker is quite small compared with the primarily mechanical

time constants of the shaker and the test package In such cases the Ledie=dt term in Equation 121 may

be neglected Consequently the equations from Equation 119 through Equation 122 may be

expressed in the Laplace (frequency) domain with the Laplace variable s taking the place of the derivative

d=dt as

ethms2 thorn bsthorn kTHORNy frac14 ethbsthorn kTHORNye eth123THORN

FIGURE 19 Dynamic models of an electromagnetic shaker and a flexible test package (a) mechanical model

(b) electrical model

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copy 2007 by Taylor amp Francis Group LLC

frac12mes2 thorn ethbthorn beTHORNsthorn ethkthorn keTHORN ye frac14 ethbsthorn kTHORNy thorn kb

Rev2

k2bs

Reye eth124THORN

It follows that the transfer function of the shaker head motion with respect to the excitation voltage is

given by

yevfrac14 kb

Re

DethsTHORNDdethsTHORN eth125THORN

where DethsTHORN is the characteristic function of the primary dynamics of the test object

DethsTHORN frac14 ms2 thorn bsthorn k eth126THORN

and DdethsTHORN is the characteristic function of the primary dynamic interactions between the shaker and thetest object

DcethsTHORN frac14 mmes4 thorn frac12methbe thorn bthorn boTHORN thornmeb s

3 thorn frac12methke thorn kTHORN thornmekthorn bethbe thorn boTHORN s2thorn frac12bke thorn ethbe thorn boTHORNk sthorn kke

eth127THORN

where

bo frac14 k2bRe

eth128THORN

It is clear that under low damping conditions DdethsTHORN will produce two resonances as it is fourth order in sand similarly DethsTHORN will produce one antiresonance (trough) corresponding to the resonance of the testobject Note that in the frequency domain s frac14 jv and hence the frequency response function given by

Equation 125 is in fact

yevfrac14 kb

Rb

DethjvTHORNDdethjvTHORN eth129THORN

The magnitude of this frequency response function for a typical test system is sketched in Figure 110

Note that this curve is for the ldquoopen-looprdquo case where there is no feedback from the shaker controller

In practice the shaker controller will be able

to compensate for the resonances and anti-

resonances to some degree depending on its

effectiveness

The main advantages of electromagnetic

shakers are their high frequency range of

operation their high degree of operating flexi-

bility and the high level of accuracy of the

generated shaker motion Faithful reproduction

of complex excitations is possible because of the

advanced electronics and control systems used in

this type of shakers Electromagnetic shakers are

not suitable for heavy-duty applications (large test

objects) however High test-input accelerations

are possible at high frequencies when electromag-

netic shakers are used but their displacement and

velocity capabilities are limited to low or

intermediate values (see Table 11)

100

10

1 10 100Excitation Frequency (Hz)

Antiresonance

Resonance

Shak

erD

ispl

acem

entM

agni

tude

Resonance

1000

FIGURE 110 Frequency response curve of a typical

electromagnetic shaker with a test object

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1221 Transient Exciters

Other varieties of exciters are commonly used in

transient-type vibration testing In these tests

either an impulsive force or an initial excitation is

applied to the test object and the resulting

response is monitored The excitations and the

responses are ldquotransientrdquo in this case Hammer

test drop tests and pluck tests fall into this

category For example a hammer test may be

conducted by hitting the object with an instru-

mented hammer and then measuring the response

of the object The hammer has a force sensor at its

tip as sketched in Figure 111 A piezoelectric or

strain-gage type force sensor may be used More

sophisticated hammers have impedance heads in

place of force sensors An impedance head

measures force and acceleration simultaneously

The results of a hammer test will depend on many

factors for example the dynamics of the hammer

body how firmly the hammer is held during the

impact how quickly the impact is applied and

whether there are multiple impacts

13 Control System

The two primary functions of the shaker control system in vibration testing are (1) to guarantee that the

specified excitation is applied to the test object and (2) to ensure that the dynamic stability (motion

constraints) of the test setup is preserved An operational block diagram illustrating these control

functions is given in Figure 112 The reference input to the control system represents the desired

excitation force that should be applied to the test object In the absence of any control however the force

reaching the test object will be distorted primarily because of (1) dynamic interactions and

nonlinearities of the shaker the test table the mounting fixtures the auxiliary instruments and the test

object itself (2) noise and errors in the signal generator amplifiers filters and other equipment and (3)

external loads and disturbances acting on the test object and other components (for example external

restraints aerodynamic forces friction) To compensate for these distorting factors response

measurements (displacements velocities acceleration and so on) are made at various locations in the

test setup and are used to control the system dynamics In particular the responses of the shaker the test

table and the test object are measured These responses are used to compare the actual excitation felt by

FIGURE 111 An instrumented hammer used in bump

tests or hammer tests

ExcitationInput

(Reference)

Feedback Paths

DriveSignal

ShakerResponse

TestTable

TestObject

Test ObjectResponse

Test TableResponseExciter

(Shaker)(Ram)

Controllerand

Amplifier

FIGURE 112 Operational block diagram illustrating a general shaker control system

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the test object at the shaker interface with the desired (specified) input The drive signal to the shaker is

modified depending on the error that is present

Two types of control are commonly employed in shaker apparatus simple manual control and

complex automatic control Manual control normally consists of simple open-loop trial-and-error

methods of manual adjustments (or calibration) of the control equipment to obtain a desired dynamic

response The actual response is usually monitored (on an oscilloscope or frequency analyzer screen for

example) during manual-control operations The pretest adjustments in manual control can be very

time-consuming as a result the test object might be subjected to overtesting which could produce

cumulative damage is undesirable and could defeat the test purpose Furthermore the calibration

procedure for the experimental setup must be repeated for each new test object

The disadvantages ofmanual control suggest that automatic control is desirable in complex test schemes

in which high accuracy of testing is desired The first step of automatic control involves automatic

measurement of the system response using control sensors and transducers The measurement is then fed

back into the control system which instantaneously determines the best drive signal to actuate the shaker

in order to get the desired excitation This may be done by either analog or digital methods

Primitive control systems require an accurate mathematical description of the test object This

dependency of the control system on the knowledge of test-object dynamics is clearly undesirable

Performance of a good control system should not be considerably affected by the dynamic interactions

and nonlinearities of the test object or by the nature of the excitation Proper selection of feedback signals

and control-system components can reduce such effects and will make the system robust

In the response-spectrum method of vibration testing it is customary to use displacement control at

low frequencies velocity control at intermediate frequency and acceleration control at high frequencies

This necessitates feedback of displacement velocity and acceleration responses Generally however the

most important feedback is the velocity feedback In sine-sweep tests the shaker velocity must change

steadily over the frequency band of interest In particular the velocity control must be precise near the

resonances of the test object Velocity (speed) feedback has a stabilizing effect on the dynamics which is

desirable This effect is particularly useful in ensuring stability in motion when testing is done near

resonances of lightly damped test objects On the contrary displacement (position) feedback can have a

destabilizing effect on some systems particularly when high feedback gains are used

The controller usually consists of various instruments equipment and computation hardware and

software Often the functions of the data-acquisition and processing system overlap with those of the

controller to some extent As an example consider the digital-controller of vibration testing apparatus

First the responses are measured through sensors (and transducers) filtered and amplified

(conditioned) These data channels may be passed through a multiplexer whose purpose is to select

one data channel at a time for processing Most modern data acquisition hardware does not need a

separate multiplexer to handle multiple signals The analog data are converted into digital data using

analog-to-digital converters (ADCs) The resulting sampled data are stored on a disk or as a block data in

the computer memory The reference input signal (typically a signal recorded on an FM tape) is also

sampled (if it is not already in the digital form) using an ADC and fed into the computer Digital

processing is done on the reference signal and the response data with the objective of computing the

command signal to drive the shaker The digital command signal is converted into an analog signal using

a digital-to-analog converter (DAC) and amplified (conditioned) before it is used to drive the exciter

The nature of the control components depends to a large extent on the nature and objectives of the

particular test to be conducted Some of the basic components in a shaker controller are described in

the following subsections

131 Components of a Shaker Controller

1311 Compressor

A compressor circuit is incorporated in automatic excitation control devices to control the excitation-

input level automatically The level of control depends on the feedback signal from a control sensor and

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the specified (reference) excitation signal Usually the compressor circuit is included in the excitation-

signal generator (for example in a sine generator) The control by this means may be done on the basis of

a single-frequency component (eg the fundamental frequency)

1312 Equalizer (Spectrum Shaper)

Random-signal equalizers are used to shape the spectrum of a random signal in a desired manner In

essence and equalizer consists of a bank of narrow-band filters (for example 80 filters) in parallel over

the operating frequency range By passing the signal through each filter the spectral density (or the mean

square value) of the signal in that narrow frequency band (for example each one-third-octave band) is

determined This is compared with the desired spectral level and automatic adjustment is made in that

filter in case there is an error In some systems response-spectrum analysis is made in place of power

spectral density analysis In that case the equalizer consists of a bank of simple oscillators whose

resonant frequencies are distributed over the operating frequency range of the equalizer The feedback

signal is passed through each oscillator and the peak value of its output is determined This value is

compared with the desired response spectrum value at that frequency If there is an error automatic gain

adjustment is made in the appropriate excitation signal components

Random-noise equalizers are used in conjunction with random signal generators They receive

feedback signals from the control sensors In some digital control systems there are algorithms (software)

that are used to iteratively converge the spectrum of the excitation signal felt by the test object into the

desired spectrum

1313 Tracking Filter

Many vibration tests are based on single-frequency excitations In such cases the control functions

should be performed on the basis of the amplitudes of the fundamental-frequency component of the

signal A tracking filter is simply a frequency-tuned band-pass filter It automatically tunes the center

frequency of its very narrow-band-pass filter to the frequency of a carrier signal Then when a noisy

signal is passed through the tuned filter the output of the filter will be the required fundamental

frequency component in the signal Tracking filters also are useful in obtaining amplitudendashfrequency

plots using an XndashY plotter In such cases the frequency value comes from the signal generator (sweep

oscillator) which produces the carrier signal to the tracking filter The tracking filter then determines the

corresponding amplitude of a signal that is fed into it Most tracking filters have dual channels so that two

signals can be handled (tracked) simultaneously

1314 Excitation Controller (Amplitude Servo-Monitor)

An excitation controller is typically an integral part of the signal generator It can be set so that automatic

sweep between two frequency limits can be performed at a selected sweep rate (linear or logarithmic)

More advanced excitation controllers have the capability of an automatic switch-over between constant-

displacement constant-velocity and constant-acceleration excitation-input control at specified

frequencies over the sweep frequency interval Consequently integrator circuits should be present

within the excitation controller unit to determine velocities and displacements from acceleration signals

Sometimes integration is performed by a separate unit called a vibration meter This unit also offers

the operator the capability of selecting the desired level of each signal (acceleration velocity or

displacement) There is an automatic cut-off level for large displacement values that could result from

noise in acceleration signals A compressor is also a subcomponent of the excitation controller The

complete unit is sometimes known as an amplitude servo-monitor

132 Signal-Generating Equipment

Shakers are force-generating devices that are operated using drive (excitation) signals generated from a

source The excitation-signal source is known as the signal generator Three major types of signal

generators are used in vibration testing applications (1) oscillators (2) random-signal generators and

(3) storage devices In some units oscillators and random-signal generators are combined We shall

Vibration Instrumentation 1-17

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copy 2007 by Taylor amp Francis Group LLC

discuss these two generators separately however because of their difference in function It also should be

noted that almost any digital signal (deterministic or random) can be generated by a digital computer

using a suitable computer program the signal eventually can be passed through a DAC to obtain

the corresponding analog signal These lsquodigitalrsquo signal generators along with analog sources such as

magnetic tape players (FM) are classified into the category of storage devices

The dynamic range of equipment is the ratio of the maximum and minimum output levels (expressed

in decibels) at which it is capable of operating without significant error This is an important specification

for many types of equipment particularly for signal-generating devices The output level of the signal

generator should be set to a value within its dynamic range

1321 Oscillators

Oscillators are essentially single-frequency generators Typically sine signals are generated but other

waveforms (such as rectangular and triangular pulses) are also available in most oscillators Normally

an oscillator has two modes of operation (1) sweeping up and down between two frequency limits and

(2) dwelling at a specified frequency In the sweep operation the sweep rate should be specified This can

be done either on a linear scale (Hzmin) or on a logarithmic scale (octavesmin) In the dwell operation

the frequency points (or intervals) should be specified In either case a desired signal level can be chosen

using the gain-control knob An oscillator that is operated exclusively in the sweep mode is called a sweep

oscillator

The early generation of oscillators employed variable inductor-capacitor types of electronic circuits to

generate signals oscillating at a desired frequency The oscillator is tuned to the required frequency by

varying the capacitance or inductance parameters A DC voltage is applied to energize the capacitor

and to obtain the desired oscillating voltage signal which subsequently is amplified and conditioned

Modern oscillators use operational amplifier circuits along with resistor capacitor and semiconductor

(SC) elements Also common are crystal (quartz) parallel-resonance oscillators used to generate voltage

signals accurately at a fixed frequency The circuit is activated using a DC-voltage source Other

frequencies of interest are obtained by passing this high-frequency signal through a frequency converter

The signal is then conditioned (amplified and filtered) Required shaping (for example rectangular

pulse) is obtained using a shape circuit Finally the required signal level is obtained by passing the

resulting signal through a variable-gain amplifier A block diagram of an oscillator illustrating various

stages in the generation of a periodic signal is given in Figure 113

A typical oscillator offers a choice of several (typically six) linear and logarithmic frequency ranges and

a sizable level of control capability (for example 80 dB) Upper and lower frequency limits in a sweep can

be preset on the front panel to any of the available frequency ranges Sweep-rate settings are continuously

DC Voltage

Oscillator

FrequencySpecification

FrequencyConverter

FilterAmplifier

ShaperPeriodicSignal

FrequencyCounter

Fixed-FrequencySignal

Variable-GainOutput

Amplifier

SignalSpecification

LevelSpecification

FIGURE 113 Block diagram of an oscillator-type signal generator

Vibration Monitoring Testing and Instrumentation1-18

53191mdash522007mdash1202mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

  • 53191fm
    • Vibration Monitoring Testing and Instrumentation
      • Preface
      • Acknowledgments
      • Editor-in-Chief
      • Contributors
      • Contents
      • Related Titles
          • 53191ch1
            • Table of Contents
            • Chapter 1 Vibration Instrumentation
              • Summary
              • 11 Introduction
              • 12 Vibration Exciters
                • 121 Shaker Selection
                  • 1211 Force Rating
                  • 1212 Power Rating
                  • 1213 Stroke Rating
                  • 1214 Hydraulic Shakers
                  • 1215 Inertial Shakers
                  • 1216 Electromagnetic Shakers
                    • 122 Dynamics of Electromagnetic Shakers
                      • 1221 Transient Exciters
                          • 13 Control System
                            • 131 Components of a Shaker Controller
                              • 1311 Compressor
                              • 1312 Equalizer (Spectrum Shaper)
                              • 1313 Tracking Filter
                              • 1314 Excitation Controller (Amplitude Servo-Monitor)
                                • 132 Signal-Generating Equipment
                                  • 1321 Oscillators
                                  • 1322 Random Signal Generators
                                  • 1323 Tape Players
                                  • 1324 Data Processing
                                      • 14 Performance Specification
                                        • 141 Parameters for Performance Specification
                                          • 1411 Time-Domain Specifications
                                          • 1412 Frequency-Domain Specifications
                                            • 142 Linearity
                                            • 143 Instrument Ratings
                                              • 1431 Rating Parameters
                                                • 144 Accuracy and Precision
                                                  • 15 Motion Sensors and Transducers
                                                    • 151 Potentiometer
                                                      • 1511 Potentiometer Resolution
                                                      • 1512 Optical Potentiometer
                                                        • 152 Variable-Inductance Transducers
                                                          • 1521 Mutual-Induction Transducers
                                                          • 1522 Linear-Variable Differential Transformer
                                                          • 1523 Signal Conditioning
                                                            • 153 Mutual-Induction Proximity Sensor
                                                            • 154 Selfinduction Transducers
                                                            • 155 Permanent-Magnet Transducers
                                                            • 156 Alternating Current Permanent-Magnet Tachometer
                                                            • 157 Alternating Current Induction Tachometer
                                                            • 158 Eddy Current Transducers
                                                            • 159 Variable-Capacitance Transducers
                                                              • 1591 Capacitive Displacement Sensors
                                                              • 1592 Capacitive Angular Velocity Sensor
                                                              • 1593 Capacitance Bridge Circuit
                                                                • 1510 Piezoelectric Transducers
                                                                  • 15101 Sensitivity
                                                                  • 15102 Piezoelectric Accelerometer
                                                                  • 15103 Charge Amplifier
                                                                      • 16 Torque Force and Other Sensors
                                                                        • 161 Strain Gage Sensors
                                                                          • 1611 Equations for Strain Gage Measurements
                                                                          • 1612 Bridge Sensitivity
                                                                          • 1613 The Bridge Constant
                                                                          • 1614 The Calibration Constant
                                                                          • 1615 Data Acquisition
                                                                          • 1616 Accuracy Considerations
                                                                          • 1617 Semiconductor Strain Gages
                                                                          • 1618 Force and Torque Sensors
                                                                          • 1619 Strain Gage Torque Sensors
                                                                          • 16110 Deflection Torque Sensors
                                                                          • 16111 Variable-Reluctance Torque Sensor
                                                                          • 16112 Reaction Torque Sensors
                                                                            • 162 Miscellaneous Sensors
                                                                              • 1621 Stroboscope
                                                                              • 1622 Fiber Optic Sensors and Lasers
                                                                              • 1623 Fiber-Optic Gyroscope
                                                                              • 1624 Laser Doppler Interferometer
                                                                              • 1625 Ultrasonic Sensors
                                                                              • 1626 Gyroscopic Sensors
                                                                                  • References
                                                                                  • Appendix 1A Virtual Instrumentation for Data Acquisition Analysis and Presentation
                                                                                    • Summary
                                                                                    • List of Abbreviations
                                                                                    • 1A1 Dynamic Signals
                                                                                      • 1A11 Acquiring and Simulating Dynamic Signals
                                                                                        • 1A111 Aliasing
                                                                                        • 1A112 Time Continuity
                                                                                            • 1A2 Measurement Configuration Considerations
                                                                                              • 1A21 Input Signal Considerations
                                                                                                • 1A211 Input Pseudodifferential and Differential Configuration
                                                                                                • 1A212 Gain
                                                                                                • 1A213 Input Coupling
                                                                                                • 1A214 Integrated Electronic Piezoelectric Excitation
                                                                                                • 1A215 Nyquist Frequency and Bandwidth
                                                                                                • 1A216 Analog-to-Digital Conversion
                                                                                                • 1A217 Antialias Filters
                                                                                                • 1A218 Input Filter Delay
                                                                                                • 1A219 Overload Detection
                                                                                                  • 1A22 Output Signal Considerations
                                                                                                    • 1A221 Output Pseudodifferential and Differential Configuration
                                                                                                    • 1A222 Attenuation
                                                                                                    • 1A223 Digital-to-Analog Conversion
                                                                                                    • 1A224 Anti-imaging and Interpolation Filters
                                                                                                    • 1A225 Output Filter Delay
                                                                                                        • 1A3 Scaling and Calibration
                                                                                                          • 1A31 Scaling to Engineering Units
                                                                                                          • 1A32 Performing System Calibration
                                                                                                            • 1A321 Propagation Delay Calibration
                                                                                                                • 1A4 Limit Testing Analysis
                                                                                                                  • 1A41 Limit Testing Overview
                                                                                                                  • 1A42 Using the SVT Limit Testing VI
                                                                                                                    • 1A5 Integration
                                                                                                                      • 1A51 Introduction to Integration
                                                                                                                      • 1A52 Implementing Integration
                                                                                                                        • 1A521 Challenges when Integrating Vibration Data
                                                                                                                          • 1A53 Time-Domain Integration
                                                                                                                            • 1A531 Single-Shot Acquisition and Integration
                                                                                                                            • 1A532 Continuous Acquisition and Integration
                                                                                                                              • 1A54 Frequency-Domain Integration
                                                                                                                                • 1A6 Vibration-Level Measurements
                                                                                                                                  • 1A61 Measuring the Root Mean Square Level
                                                                                                                                    • 1A611 Single-Shot Buffered Acquisition
                                                                                                                                    • 1A612 Continuous Signal Acquisition
                                                                                                                                      • 1A62 Performing a Running RMS Level Measurement
                                                                                                                                      • 1A63 Computing the Peak Level
                                                                                                                                      • 1A64 Computing the Crest Factor
                                                                                                                                        • 1A7 Frequency Analysis
                                                                                                                                          • 1A71 FFT Fundamentals
                                                                                                                                            • 1A711 Number of Samples
                                                                                                                                            • 1A712 Frequency Resolution
                                                                                                                                            • 1A713 Maximum Resolvable Frequency
                                                                                                                                            • 1A714 Minimum Resolvable Frequency
                                                                                                                                            • 1A715 Number of Spectral Lines
                                                                                                                                            • 1A716 Relationship between Time-Domain and Frequency-Domain Specifications and Parameters
                                                                                                                                              • 1A72 Increasing Frequency Resolution
                                                                                                                                                • 1A721 Zoom FFT Analysis
                                                                                                                                                • 1A722 Frequency Resolution of the Zoom FFT VIs
                                                                                                                                                • 1A723 Zoom Measurement
                                                                                                                                                • 1A724 Zoom Settings
                                                                                                                                                • 1A725 Subset Analysis
                                                                                                                                                    • 1A8 Transient Analysis
                                                                                                                                                      • 1A81 Transient Analysis with the Sound and Vibration Toolkit
                                                                                                                                                      • 1A82 Performing an STFT vs Time
                                                                                                                                                        • 1A821 Selecting the FFT Block Size
                                                                                                                                                        • 1A822 Overlapping
                                                                                                                                                        • 1A823 Using the SVT STFT vs Time VI
                                                                                                                                                          • 1A83 Performing an STFT vs Rotational Speed
                                                                                                                                                            • 1A831 Converting the Pulse Train to Rotational Speed
                                                                                                                                                            • 1A832 STFT vs RPM
                                                                                                                                                              • 1A84 Measuring a Shock Response Spectrum
                                                                                                                                                                • 1A9 Waterfall Display
                                                                                                                                                                  • 1A91 Using the Display VIs
                                                                                                                                                                    • 1A911 Initializing the Display
                                                                                                                                                                    • 1A912 Sending Data to the Display
                                                                                                                                                                    • 1A913 Waterfall Display for Frequency Analysis
                                                                                                                                                                    • 1A914 Waterfall Display for Transient Analysis
                                                                                                                                                                    • 1A915 Waterfall Display for Octave Spectra
                                                                                                                                                                        • 1A10 Swept-Sine Measurements
                                                                                                                                                                          • 1A101 Swept-Sine Overview
                                                                                                                                                                          • 1A102 Choosing Swept-Sine vs FFT Measurements
                                                                                                                                                                          • 1A103 Taking a Swept-Sine Measurement
                                                                                                                                                                          • 1A104 Swept-Sine Measurement Example
                                                                                                                                                                              • Bibliography
                                                                                                                                                                              • Related Titles
                                                                                                                                                                                  • 53191ch2
                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                    • Chapter 2 Signal Conditioning and Modification
                                                                                                                                                                                      • Summary
                                                                                                                                                                                      • 21 Introduction
                                                                                                                                                                                      • 22 Amplifiers
                                                                                                                                                                                        • 221 Operational Amplifier
                                                                                                                                                                                        • 222 Use of Feedback in Opamp
                                                                                                                                                                                        • 223 Voltage Current and Power Amplifiers
                                                                                                                                                                                          • 2231 Charge Amplifiers
                                                                                                                                                                                            • 224 Instrumentation Amplifiers
                                                                                                                                                                                              • 2241 Differential Amplifier
                                                                                                                                                                                              • 2242 Common Mode
                                                                                                                                                                                                • 225 Amplifier Performance Ratings
                                                                                                                                                                                                  • 2251 Common-Mode Rejection Ratio
                                                                                                                                                                                                    • 226 Component Interconnection
                                                                                                                                                                                                      • 2261 Impedance Characteristics
                                                                                                                                                                                                      • 2262 Cascade Connection of Devices
                                                                                                                                                                                                      • 2263 AC-Coupled Ampliers
                                                                                                                                                                                                          • 23 Analog Filters
                                                                                                                                                                                                            • 231 Passive Filters and Active Filters
                                                                                                                                                                                                              • 2311 Number of Poles
                                                                                                                                                                                                                • 232 Low-Pass Filters
                                                                                                                                                                                                                  • 2321 Low-Pass Butterworth Filter
                                                                                                                                                                                                                    • 233 High-Pass Filters
                                                                                                                                                                                                                    • 234 Band-Pass Filters
                                                                                                                                                                                                                      • 2341 Resonance-Type Band-Pass Filters
                                                                                                                                                                                                                        • 235 Band-Reject Filters
                                                                                                                                                                                                                          • 24 Modulators and Demodulators
                                                                                                                                                                                                                            • 241 Amplitude Modulation
                                                                                                                                                                                                                              • 2411 Modulation Theorem
                                                                                                                                                                                                                              • 2412 Side Frequencies and Side Bands
                                                                                                                                                                                                                                • 242 Application of Amplitude Modulation
                                                                                                                                                                                                                                  • 2421 Fault Detection and Diagnosis
                                                                                                                                                                                                                                    • 243 Demodulation
                                                                                                                                                                                                                                      • 25 Analog ndashDigital Conversion
                                                                                                                                                                                                                                        • 251 Digital-to-Analog Conversion
                                                                                                                                                                                                                                          • 2511 DAC Error Sources
                                                                                                                                                                                                                                            • 252 Analog-to-Digital Conversion
                                                                                                                                                                                                                                            • 253 Analog-to-Digital Converter Performance Characteristics
                                                                                                                                                                                                                                              • 2531 Resolution and Quantization Error
                                                                                                                                                                                                                                              • 2532 Monotonicity Nonlinearity and Offset Error
                                                                                                                                                                                                                                              • 2533 Analog-to-Digital Converter Conversion Rate
                                                                                                                                                                                                                                                • 254 Sample-and-Hold Circuitry
                                                                                                                                                                                                                                                • 255 Digital Filters
                                                                                                                                                                                                                                                  • 2551 Software Implementation and Hardware Implementation
                                                                                                                                                                                                                                                      • 26 Bridge Circuits
                                                                                                                                                                                                                                                        • 261 Wheatstone Bridge
                                                                                                                                                                                                                                                        • 262 Constant-Current Bridge
                                                                                                                                                                                                                                                        • 263 Bridge Amplifiers
                                                                                                                                                                                                                                                          • 2631 Half-Bridge Circuits
                                                                                                                                                                                                                                                            • 264 Impedance Bridges
                                                                                                                                                                                                                                                              • 2641 Owen Bridge
                                                                                                                                                                                                                                                              • 2642 Wien-Bridge Oscillator
                                                                                                                                                                                                                                                                  • 27 Linearizing Devices
                                                                                                                                                                                                                                                                    • 271 Linearization by Software
                                                                                                                                                                                                                                                                    • 272 Linearization by Hardware Logic
                                                                                                                                                                                                                                                                    • 273 Analog Linearizing Circuitry
                                                                                                                                                                                                                                                                    • 274 Offsetting Circuitry
                                                                                                                                                                                                                                                                    • 275 Proportional-Output Circuitry
                                                                                                                                                                                                                                                                      • 2751 Curve-Shaping Circuitry
                                                                                                                                                                                                                                                                          • 28 Miscellaneous Signal Modification Circuitry
                                                                                                                                                                                                                                                                            • 281 Phase Shifters
                                                                                                                                                                                                                                                                            • 282 Voltage-to-Frequency Converter
                                                                                                                                                                                                                                                                            • 283 Frequency-to-Voltage Converter
                                                                                                                                                                                                                                                                            • 284 Voltage-to-Current Converters
                                                                                                                                                                                                                                                                            • 285 Peak-Hold Circuits
                                                                                                                                                                                                                                                                              • 29 Signal Analyzers and Display Devices
                                                                                                                                                                                                                                                                                • 291 Signal Analyzers
                                                                                                                                                                                                                                                                                • 292 Oscilloscopes
                                                                                                                                                                                                                                                                                  • 2921 Triggering
                                                                                                                                                                                                                                                                                  • 2922 Lissajous Patterns
                                                                                                                                                                                                                                                                                  • 2923 Digital Oscilloscopes
                                                                                                                                                                                                                                                                                      • Bibliography
                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                          • 53191ch3
                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                            • Chapter 3 Vibration Testing
                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                              • 31 Introduction
                                                                                                                                                                                                                                                                                              • 32 Representation of a Vibration Environment
                                                                                                                                                                                                                                                                                                • 321 Test Signals
                                                                                                                                                                                                                                                                                                  • 3211 Stochastic vs Deterministic Signals
                                                                                                                                                                                                                                                                                                    • 322 Deterministic Signal Representation
                                                                                                                                                                                                                                                                                                      • 3221 Single-Frequency Signals
                                                                                                                                                                                                                                                                                                      • 3222 Sine Sweep
                                                                                                                                                                                                                                                                                                      • 3223 Sine Dwell
                                                                                                                                                                                                                                                                                                      • 3224 Decaying Sine
                                                                                                                                                                                                                                                                                                      • 3225 Sine Beat
                                                                                                                                                                                                                                                                                                      • 3226 Sine Beat with Pauses
                                                                                                                                                                                                                                                                                                      • 3227 Multifrequency Signals
                                                                                                                                                                                                                                                                                                      • 3228 Actual Excitation Records
                                                                                                                                                                                                                                                                                                      • 3229 Simulated Excitation Signals
                                                                                                                                                                                                                                                                                                        • 323 Stochastic Signal Representation
                                                                                                                                                                                                                                                                                                          • 3231 Ergodic Random Signals
                                                                                                                                                                                                                                                                                                          • 3232 Stationary Random Signals
                                                                                                                                                                                                                                                                                                          • 3233 Independent and Uncorrelated Signals
                                                                                                                                                                                                                                                                                                          • 3234 Transmission of Random Excitations
                                                                                                                                                                                                                                                                                                            • 324 Frequency-Domain Representations
                                                                                                                                                                                                                                                                                                              • 3241 Fourier Spectrum Method
                                                                                                                                                                                                                                                                                                              • 3242 Power Spectral Density Method
                                                                                                                                                                                                                                                                                                                • 325 Response Spectrum
                                                                                                                                                                                                                                                                                                                  • 3251 Displacement Velocity and Acceleration Spectra
                                                                                                                                                                                                                                                                                                                  • 3252 Response-Spectra Plotting Paper
                                                                                                                                                                                                                                                                                                                  • 3253 Zero-Period Acceleration
                                                                                                                                                                                                                                                                                                                  • 3254 Uses of Response Spectra
                                                                                                                                                                                                                                                                                                                    • 326 Comparison of Various Representations
                                                                                                                                                                                                                                                                                                                      • 33 Pretest Procedures
                                                                                                                                                                                                                                                                                                                        • 331 Purpose of Testing
                                                                                                                                                                                                                                                                                                                        • 332 Service Functions
                                                                                                                                                                                                                                                                                                                          • 3321 Active Equipment
                                                                                                                                                                                                                                                                                                                          • 3322 Passive Equipment
                                                                                                                                                                                                                                                                                                                          • 3323 Functional Testing
                                                                                                                                                                                                                                                                                                                            • 333 Information Acquisition
                                                                                                                                                                                                                                                                                                                              • 3331 Interface Details
                                                                                                                                                                                                                                                                                                                              • 3332 Effect of Neglecting Interface Dynamics
                                                                                                                                                                                                                                                                                                                              • 3333 Effects of Damping
                                                                                                                                                                                                                                                                                                                              • 3334 Effects of Inertia
                                                                                                                                                                                                                                                                                                                              • 3335 Effect of Natural Frequency
                                                                                                                                                                                                                                                                                                                              • 3336 Effect of Excitation Frequency
                                                                                                                                                                                                                                                                                                                              • 3337 Other Effects of Interface
                                                                                                                                                                                                                                                                                                                                • 334 Test-Program Planning
                                                                                                                                                                                                                                                                                                                                  • 3341 Testing of Cabinet-Mounted Equipment
                                                                                                                                                                                                                                                                                                                                    • 335 Pretest Inspection
                                                                                                                                                                                                                                                                                                                                      • 34 Testing Procedures
                                                                                                                                                                                                                                                                                                                                        • 341 Resonance Search
                                                                                                                                                                                                                                                                                                                                        • 342 Methods of Determining Frequency-Response Functions
                                                                                                                                                                                                                                                                                                                                          • 3421 Fourier Transform Method
                                                                                                                                                                                                                                                                                                                                          • 3422 Spectral Density Method
                                                                                                                                                                                                                                                                                                                                          • 3423 Harmonic Excitation Method
                                                                                                                                                                                                                                                                                                                                            • 343 Resonance-Search Test Methods
                                                                                                                                                                                                                                                                                                                                              • 3431 Hammer (Bump) Test and Drop Test
                                                                                                                                                                                                                                                                                                                                              • 3432 Pluck Test
                                                                                                                                                                                                                                                                                                                                              • 3433 Shaker Tests
                                                                                                                                                                                                                                                                                                                                                • 344 Mechanical Aging
                                                                                                                                                                                                                                                                                                                                                  • 3441 Equivalence for Mechanical Aging
                                                                                                                                                                                                                                                                                                                                                  • 3442 Excitation-Intensity Equivalence
                                                                                                                                                                                                                                                                                                                                                  • 3443 Dynamic-Excitation Equivalence
                                                                                                                                                                                                                                                                                                                                                  • 3444 Cumulative Damage Theory
                                                                                                                                                                                                                                                                                                                                                    • 345 Test-Response Spectrum Generation
                                                                                                                                                                                                                                                                                                                                                    • 346 Instrument Calibration
                                                                                                                                                                                                                                                                                                                                                    • 347 Test-Object Mounting
                                                                                                                                                                                                                                                                                                                                                    • 348 Test-Input Considerations
                                                                                                                                                                                                                                                                                                                                                      • 3481 Test Nomenclature
                                                                                                                                                                                                                                                                                                                                                      • 3482 Testing with Uncorrelated Excitations
                                                                                                                                                                                                                                                                                                                                                      • 3483 Symmetrical Rectilinear Testing
                                                                                                                                                                                                                                                                                                                                                      • 3484 Geometry vs Dynamics
                                                                                                                                                                                                                                                                                                                                                      • 3485 Some Limitations
                                                                                                                                                                                                                                                                                                                                                      • 3486 Testing Black Boxes
                                                                                                                                                                                                                                                                                                                                                      • 3487 Phasing of Excitations
                                                                                                                                                                                                                                                                                                                                                      • 3488 Testing a Gray or White Box
                                                                                                                                                                                                                                                                                                                                                      • 3489 Overtesting in Multitest Sequences
                                                                                                                                                                                                                                                                                                                                                          • 35 Some Practical Information
                                                                                                                                                                                                                                                                                                                                                            • 351 Random Vibration Test Example
                                                                                                                                                                                                                                                                                                                                                            • 352 Vibration Shakers and Control Systems
                                                                                                                                                                                                                                                                                                                                                              • Bibliography
                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                  • 53191ch4
                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                    • Chapter 4 Experimental Modal Analysis
                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                      • 41 Introduction
                                                                                                                                                                                                                                                                                                                                                                      • 42 Frequency-Domain Formulation
                                                                                                                                                                                                                                                                                                                                                                        • 421 Transfer-Function Matrix
                                                                                                                                                                                                                                                                                                                                                                        • 422 Principle of Reciprocity
                                                                                                                                                                                                                                                                                                                                                                          • 43 Experimental Model Development
                                                                                                                                                                                                                                                                                                                                                                            • 431 Extraction of the Time-Domain Model
                                                                                                                                                                                                                                                                                                                                                                              • 44 Curve Fitting of Transfer Functions
                                                                                                                                                                                                                                                                                                                                                                                • 441 Problem Identification
                                                                                                                                                                                                                                                                                                                                                                                • 442 Single- and Multi-Degree-of-Freedom Techniques
                                                                                                                                                                                                                                                                                                                                                                                • 443 Single-Degree-of-Freedom Parameter Extraction in the Frequency Domain
                                                                                                                                                                                                                                                                                                                                                                                  • 4431 Circle-Fit Method
                                                                                                                                                                                                                                                                                                                                                                                    • Case of Viscous Damping
                                                                                                                                                                                                                                                                                                                                                                                    • Case of Hysteretic Damping
                                                                                                                                                                                                                                                                                                                                                                                      • 4432 Peak-Picking Method
                                                                                                                                                                                                                                                                                                                                                                                        • 444 Multi-Degree of Freedom Curve Fitting
                                                                                                                                                                                                                                                                                                                                                                                          • 4441 Formulation of the Method
                                                                                                                                                                                                                                                                                                                                                                                            • 445 A Comment on Static Modes and Rigid-Body Modes
                                                                                                                                                                                                                                                                                                                                                                                            • 446 Residue Extraction
                                                                                                                                                                                                                                                                                                                                                                                              • 45 Laboratory Experiments
                                                                                                                                                                                                                                                                                                                                                                                                • 451 Lumped-Parameter System
                                                                                                                                                                                                                                                                                                                                                                                                  • 4511 Frequency-Domain Test
                                                                                                                                                                                                                                                                                                                                                                                                  • 4512 Time-Domain Tests
                                                                                                                                                                                                                                                                                                                                                                                                    • 452 Distributed-Parameter System
                                                                                                                                                                                                                                                                                                                                                                                                      • 46 Commercial EMA Systems
                                                                                                                                                                                                                                                                                                                                                                                                        • 461 System Configuration
                                                                                                                                                                                                                                                                                                                                                                                                          • 4611 FFT Analysis Options
                                                                                                                                                                                                                                                                                                                                                                                                          • 4612 Modal Analysis Components
                                                                                                                                                                                                                                                                                                                                                                                                              • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                  • 53191ch5
                                                                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                    • Chapter 5 Mechanical Shock
                                                                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                      • 51 Definitions
                                                                                                                                                                                                                                                                                                                                                                                                                        • 511 Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 512 Simple (or Perfect) Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 513 Half-Sine Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 514 Versed-Sine (or Haversine) Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 515 Terminal Peak Sawtooth Shock or Final Peak Sawtooth Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 516 Rectangular Shock
                                                                                                                                                                                                                                                                                                                                                                                                                          • 5161 Trapezoidal Shock
                                                                                                                                                                                                                                                                                                                                                                                                                              • 52 Description in the Time Domain
                                                                                                                                                                                                                                                                                                                                                                                                                              • 53 Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                • 531 Need
                                                                                                                                                                                                                                                                                                                                                                                                                                • 532 Shock Response Spectrum Definition
                                                                                                                                                                                                                                                                                                                                                                                                                                • 533 Response of a Linear One-Degree-of-Freedom System
                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5331 Shock Defined by a Force
                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5332 Shock Defined by an Acceleration
                                                                                                                                                                                                                                                                                                                                                                                                                                    • 534 Definitions
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5341 Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5342 Absolute Acceleration Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5343 Relative Displacement Shock Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5344 Primary Positive Shock Response Spectrum or Initial Positive Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5345 Primary (or Initial) Negative Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5346 Secondary (or Residual) Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5347 Positive (or Maximum Positive) Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5348 Negative (or Maximum Negative) Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5349 Maximax Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53410 Choice of Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                        • 535 Standardized Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5351 Definition
                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5352 Standardized Shock Response Spectra of Simple Shocks
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53521 Half-Sine Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53522 Versed Sine Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53523 Terminal Peak Sawtooth Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53524 Rectangular Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53525 Trapezoidal Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 536 Choice of Damping
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 537 Shock Response Spectra Domains
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 538 Algorithms for Calculation of the Shock Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 539 Choice of the Digitization Frequency of the Signal
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5310 Use of Shock Response Spectra for the Study of Systems with Several Degrees of Freedom
                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 54 Pyroshocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 55 Use of Shock Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 551 Severity Comparison of Several Shocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 552 Test Specification Development from Real Environment Data
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5521 Synthesis of Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5522 Nature of the Specification
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5523 Choice of Shape
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5524 Amplitude
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5525 Duration
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5526 Difficulties
                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 56 Standards
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 561 Types of Standards
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 562 Installation Conditions of Test Item
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 563 Uncertainty Factor
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 564 Bump Test
                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 57 Damage Boundary Curve
                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 571 Definition
                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 572 Analysis of Test Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 58 Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 581 Main Types
                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 582 Impact Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5821 Universal Shock-Test Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 58211 Impact Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 58212 Impulse Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 583 Shock Simulators (Programmers)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5831 Half-Sine Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58311 Shock Duration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58312 Impact Velocity
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58313 Maximum Deformation of the Shock Simulator (Programmer)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58314 Shock Amplitude
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58315 Characteristics of the Target
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5832 Terminal Peak Sawtooth Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5833 Rectangular Pulse ndash Trapezoidal Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5834 Universal Shock Simulator (Programmer)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 58341 Generating a Half-Sine Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 58342 Generating a Terminal Peak Sawtooth Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 58343 Trapezoidal Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 584 Limitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5841 Limitations of the Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5842 Limitations of Shock Simulators
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 585 Pneumatic Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 586 High Impact Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5861 Lightweight High Impact Shock Machine
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5862 Medium Weight High Impact Shock Machine
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 587 Specific Test Facilities
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 59 Generation of Shock Using Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 591 Principle Behind the Generation of a Simple Shape Signal versus Time
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 592 Main Advantages
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 593 Pre- and Postshocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5931 Requirements
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5932 Solutions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 59321 Optimized Pre- and Postpulses
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5933 Incidence on the Shock Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 594 Limitations of Electrodynamic Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5941 Mechanical Limitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 59411 Abacuses
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5942 Electronic Limitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 595 The Use of Electrohydraulic Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 510 Control by a Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 5101 Principle
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 5102 Principal Shapes of Elementary Signals
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 51021 Decaying Sinusoid
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 51022 ZERD Function
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 51023 WAVSIN Waveform
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 5103 Comparison of WAVSIN SHOC Waveforms and Decaying Sinusoid
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 5104 Criticism of Control by a Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 511 Pyrotechnic Shock Simulation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5111 Simulation Using Pyrotechnic Facilities
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5112 Simulation Using Metal-to-Metal Impact
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5113 Simulation Using Electrodynamic Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5114 Simulation Using Conventional Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53191ch6
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Chapter 6 Machine Condition Monitoring and Fault Diagnostics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 61 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 62 Machinery Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 621 Causes of Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 622 Types of Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 623 Frequency of Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 63 Basic Maintenance Strategies
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 631 Run-to-Failure (Breakdown) Maintenance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 632 Scheduled (Preventative) Maintenance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 633 Condition-Based (Predictive Proactive Reliability Centered On-Condition) Maintenance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 64 Factors Which Influence Maintenance Strategy
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 65 Machine Condition Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 651 Periodic Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 652 Continuous Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 66 Transducer Selection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 661 Noncontact Displacement Transducers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 662 Velocity Transducers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 663 Acceleration Transducers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 67 Transducer Location
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 68 Recording and Analysis Instrumentation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 681 Vibration Meters
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 682 Data Collectors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 683 Frequency-Domain Analyzers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 684 Time-Domain Instruments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 685 Tracking Analyzers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 69 Display Formats and Analysis Tools
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 691 Time Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6911 Time-Waveform Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6912 Time-Waveform Indices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6913 Time-Synchronous Averaging
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6914 Negative Averaging
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6915 Orbits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6916 Probability Density Functions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6917 Probability Density Moments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 692 Frequency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6921 Band-Pass Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6922 Shock Pulse (Spike Energy)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6923 Enveloped Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6924 Signature Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6925 Cascades (Waterfall Plots)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6926 Masks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6927 Frequency-Domain Indices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 693 Modal Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 694 Quefrency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 610 Fault Detection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 6101 Standards
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61011 Standards Based on Machinery Type
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61012 Standards Based on Vibration Severity
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 6102 Acceptance Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 61021 Statistical Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 6103 Frequency-Domain Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61031 Limited Band Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61032 Constant Bandwidth Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61033 Constant Percentage Bandwidth Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 611 Fault Diagnostics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 6111 Forcing Functions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61111 Unbalance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61112 Misalignment
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61113 Mechanical Looseness
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61114 Soft Foot
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61115 Rubs
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61116 Resonances
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61117 Oil Whirl
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61118 Oil Whip
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61119 Structural Vibrations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 611110 Foundation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 6112 Specific Machine Components
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 61121 Damaged or Worn Rolling-Element Bearings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 61122 Damaged or Worn Gears
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 6113 Specific Machine Types
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61131 Pumps
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61132 Fans
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61133 Electric Motors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61134 Steam and Gas Turbines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61135 Compressors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61136 Reciprocating Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 6114 Advanced Fault Diagnostic Techniques
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 53191ch7
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • Chapter 7 Vibration-Based Tool Condition Monitoring Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 71 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 72 Mechanics of Turning
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 721 General Terms
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 722 Chatter Vibrations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 723 Tool Wear
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7231 Tool Failure Mechanisms
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7232 Tool Failure Modes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7233 Tool Wear Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7234 Tool Wear Stages
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 73 Vibration Signal Recording
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 731 Direct and Indirect Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 732 Sensor Requirements for Tool Wear Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 733 Force Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7331 Direct Measurement Dynamometers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7332 Indirect Force Sensors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7333 Piezoelectric Strain Sensors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7334 Resistance Strain Gauges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7335 Customized Force Sensors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 734 Acceleration Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 735 Acoustic Emission Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 736 Sensor Comparisons
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 74 Signal Processing for Sensor-Based Tool Condition Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 741 Feature Extraction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7411 Time Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7412 Frequency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7413 Statistical Processing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7414 TimendashFrequency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 742 Feature Selection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 75 Wear ModelDecision-Making for Sensor-Based Tool Condition Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 751 Trending Threshold
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 752 Neural Networks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7521 Unsupervised Networks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7522 Supervised Networks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 753 Fuzzy Logic
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 754 Other Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 76 Conclusion
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53191ch8
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Chapter 8 Fault Diagnosis of Helicopter Gearboxes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 81 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 82 Abnormality Scaling
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 83 The Structure-Based Connectionist Network
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 84 Sensor Location Selection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 841 Coverage Index
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 842 Overlap Index
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 843 Monitoring Effectiveness
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 85 A Case Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 851 Structural and Featural Influences
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 852 Evaluation of Influences
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 853 Fault Detection Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 854 Fault Diagnostic Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 8541 Faulty Subsystem Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 8542 Faulty Component Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 855 Sensor Location Evaluation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 856 Sensor Location Validation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 86 Conclusion
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 53191ch9
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Chapter 9 Vibration Suppression and Monitoring in Precision Motion Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 91 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 92 Mechanical Design to Minimize Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 921 Stability and Static Determinacy of Machine Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 922 Two-Dimensional Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 923 Three-Dimensional Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 93 Adaptive Notch Filter
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 931 Fast Fourier Transform
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 932 Simulation and Experiments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 94 Real-Time Vibration Analyzer
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 941 Learning Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 942 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 943 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 944 Experiments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 9441 Input Variables mdash the Evaluation Criteria
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 94411 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 94412 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 9442 Evaluation Rules
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 94421 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 94422 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 9443 Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 94431 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 94432 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 95 Practical Insights and Case Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 96 Conclusions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 53191ch10
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Chapter 10 Vibration and Shock Problems of Civil Engineering Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 101 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 102 Earthquake-Induced Vibration of Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1021 Seismicity and Ground Motions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1022 Influence of Local Site Conditions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1023 Response of Structures to Ground Motions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1024 Dynamic Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10241 Equations of Motion for Linear Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10242 Equations of Motion for Linear Multiple-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1025 Earthquake Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10251 Elastic Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10252 Smoothed Design Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10253 Ductility-Modified Response Spectrum Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1026 Design Philosophy and the Code Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10261 Performance-Based Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1027 Analysis Options for Earthquake Effects
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10271 Dynamic Time History Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10272 Response Spectrum Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 102721 Response Spectrum Analysis of Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 102722 Response Spectrum Analysis of Multi-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10273 Equivalent Static Analysis (Force-Based Approach)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10274 Displacement-Based Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1028 SoilndashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1029 Active and Passive Control Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 10210 Worked Examples
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 103 Dynamic Effects of Wind Loading on Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1031 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1032 Wind Speed
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1033 Design Structures for Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10331 Types of Wind Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10332 Design Criteria
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10333 Static Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1034 Along and Across-Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10341 Along-Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10342 Across-Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1035 Wind Tunnel Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1036 Comfort Criteria Human Response to Building Motion
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1037 Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1038 Comparison with Earthquake Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 104 Vibrations Due to Fluid ndashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1041 Added Mass and Inertial Coupling
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1042 Wave-Induced Vibration of Structure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 105 Blast Loading and Blast Effects on Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1051 Explosions and Blast Phenomenon
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1052 Explosive Air-Blast Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10521 Blast Wave Scaling Laws
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10522 Prediction of Blast Pressure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1053 Gas Explosion Loading and Effect of Internal Explosions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1054 Structural Response to Blast Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10541 Elastic Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10542 Elasto-Plastic Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1055 Material Behaviors at High Strain Rate
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10551 Dynamic Properties of Concrete under High Strain Rates
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10552 Dynamic Properties of Reinforcing Steel under High Strain Rates
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1056 Failure Modes of Blast-Loaded Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10561 Global Structural Behavior
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10562 Localized Structural Behavior
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10563 PressurendashImpulse ( PndashI ) Diagrams
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1057 Blast WavendashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1058 Effect of Ground Shocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10581 Loads from Air-Induced Ground Shock
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10582 Loads from Direct Ground Shock
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1059 Technical Design Manuals for Blast-Resistant Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 10510 Computer Programs for Blast and Shock Effects
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 106 Impact Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1061 Structural Impact between Two Bodies mdash Hard Impact and Soft Impact
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1062 Example mdash Aircraft Impact
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 107 Floor Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1071 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1072 Types of Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10721 Walking
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10722 Rhythmic Activities
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10723 Mechanical Equipment
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10724 Analysis Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1073 Natural Frequency of Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10731 Computing the Natural Frequency
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10732 Computing Deflection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10733 Damping
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10734 Resonance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1074 Vibration Caused by Walking
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10741 Minimum Natural Frequency
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1075 Design for Rhythmic Excitation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10751 Harmonics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10752 Minimum Natural Frequency
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1076 Example mdash Vibration Analysis of a Reinforced Concrete Floor
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 53191ch11
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Chapter 11 Seismic Base Isolation and Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 111 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1111 From Ductility Design to Base Isolation and Control Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1112 The Importance of Reducing Seismic Input and Response
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 112 Seismic Base Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1121 Historical Development of Base Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1122 Basic Principle
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1123 Issues in Seismic Base Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11231 Performance Criteria
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11232 Type of Structure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11233 Site Characteristics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11234 Retrofit Issues
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11235 Design of Building Services
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11236 Expected Life of Isolator
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1124 Seismic Isolation Devices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11241 Laminated Rubber Bearings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11242 Lead Rubber Bearing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11243 Friction-Based Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11244 Other Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1125 Design of Isolation Devices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11251 High-Damping Rubber Bearing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112511 Stability against Buckling
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112512 Stability against Roll Out
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11252 Lead Rubber Bearings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112521 Design of Lead Plug
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112522 Design of Laminated Rubber Bearing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11253 Design of Friction Pendulum System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1126 Verification of Properties of Isolation Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11261 Tests for Isolation Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 112611 System Characterization Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 112612 Prototype Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 112613 Quality Control Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11262 Uniform Building Code Recommendations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112621 Units Dependent on Loading Rates
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112622 Units Dependent on Bilateral Load
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112623 System Adequacy
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1127 Analysis of Base-Isolated Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11271 Modeling of a Superstructure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11272 Modeling of Isolation System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11273 Static Analysis Procedure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11274 Dynamic Analysis Procedure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 112741 Response Spectrum Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 112742 Time-History Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11275 Software for Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1128 Experimental Methods for Isolated Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1129 Implementation of Seismic Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11291 New Construction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112911 Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112912 Bridges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11292 Seismic Retrofit
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112921 Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112922 Bridges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11293 Other Implementations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 11210 Performance during Past Earthquakes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 112101 Performance of Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 112102 Performance of Bridges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 113 Seismic Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1131 Historical Development of Seismic Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1132 Basic Principles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11321 Passive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11322 Active Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11323 Semiactive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11324 Hybrid Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11325 Categorization of Basic Principles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1133 Important Issues in Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11331 SoilndashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11332 DevicendashStructure Interaction and Time Delay
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11333 Design Guidelines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1134 Vibration-Control Devices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11341 Passive Control Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113411 Metallic Yielding Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113412 Friction Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113413 Viscoelastic Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113414 Viscous Fluid Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113415 Tuned Mass Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11342 Active Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113421 Electromagnetic Actuator
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113422 Hydraulic Actuators
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11343 Semiactive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113431 Variable-Orifice Hydraulic Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113432 Controllable Fluid Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113433 Controllable Friction Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11344 Hybrid Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1135 Control Algorithm
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11351 Active Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11352 Semiactive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113521 Common Control Schemes for Controllable Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113522 Special Control Schemes for Controllable Damper
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1136 Experimental Performance Verification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11361 Shaking Table Tests of a Flexible Structural Model with TMD AMD and ATMD
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11362 Substructure Hybrid Test
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113621 Hybrid Tests Using Hydraulic Actuator
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113622 Hybrid Tests Using Shaking Table
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113623 Hybrid Tests Using Inertia-Force-Driven Loading System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1137 Implementations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11371 Semiactive Control of Full-Scale Structures Using Variable Joint Damper System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113711 Background of Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113712 Test System Set Up
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113713 Control Algorithm
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113714 Test Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11372 Application of Structural Control Technologies to Seismic Retrofit of a Cable-Stayed Bridge
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113721 Background of Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113722 Basic Concept of Seismic Retrofit
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113723 Modal Shape Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113724 Time-History Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113725 Soil ndash Structure Interaction Effect
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113726 Semiactive Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53191ch12
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Chapter 12 Seismic Random Vibration of Long-Span Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 121 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1211 Basic Concepts of Random Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12111 Stationary Random Process
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12112 Nonstationary Random Process
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1212 Three Methods for Structural Seismic Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12121 Response Spectrum Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12122 Time-History Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12123 Random Vibration Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 121231 Davenport Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 121232 Vanmarcke Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 12124 Comparisons of the Three Seismic-Analysis Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 122 Seismic Random-Excitation Fields
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1221 Power Spectral Density of Spatially Varying Ground Acceleration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1222 Several Coherence Models
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12221 FengndashHu Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12222 Harichandran ndashVanmarcke Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12223 LohndashYeh Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12224 OliveirandashHaondashPenzien Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12225 LucondashWong Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12226 QundashWangndashWang Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1223 Generation of Ground Acceleration Power Spectral Density Curves from Acceleration Response Spectrum Curves
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12231 Kaul Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12232 Iteration Scheme
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1224 Seismic Equations of Motion of Long-Span Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1225 Seismic Waves and Their Geometrical Expressions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 123 Pseudoexcitation Method for Structural Random Vibration Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1231 Structures Subjected to Stationary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12311 Single Stationary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12312 Multiple Stationary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1232 Structures Subjected to Nonstationary Random Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12321 Structures Subjected to Uniformly Modulated Evolutionary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 123211 Single Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 123212 Multiple Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12322 Structures Subjected to Nonuniformly Modulated Evolutionary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 123221 Single Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 123222 Multiple Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1233 Precise Integration Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12331 Precise Integration of Exponential Matrices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12332 Particular Solutions and Precise Integration Formulas for Various Forms of Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 123321 Linear Loading Form (HPD-L Form)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 123322 Sinusoidal Loading Form (HPD-S Form)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 123323 Exponentially Decaying Sinusoidal Loading Form (HPD-E Form)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 124 Long-Span Structures Subjected to Stationary Random Ground Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1241 The Solution of Equations of Motion Using the Pseudoexcitation Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1242 Numerical Comparisons with Other Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12421 Song-Hua-Jiang Suspension Bridge
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 124211 All Supports Move Uniformly
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 124212 Wave Passage Effect Is Taken into Account
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 124213 Wave-Passage Effect and Incoherence Effect Are Jointly Taken into Account
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 12422 San Joaquin Concrete Bridge
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 125 Long-Span Structures Subjected to Nonstationary Random Ground Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1251 Modulation Functions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1252 The Formulas for Nonstationary Multiexcitation Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1253 Expected Extreme Values of Nonstationary Random Processes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1254 Numerical Comparisons with the Corresponding Stationary Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 126 Conclusions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 53191ch13
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Chapter 13 Seismic Qualification of Equipment
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 131 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 132 Distribution Qualification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1321 Drive-Signal Generation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1322 Distribution Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1323 Test Procedures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 133 Seismic Qualification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1331 Stages of Seismic Qualification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1332 Test Preliminaries
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1333 Single-Frequency Testing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1334 Multifrequency Testing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1335 Generation of RRS Specifications
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 53191ch14
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Chapter 14 Human Response to Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 141 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 142 Vibration Excitations on Humans
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1421 Excitation Characteristics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 143 Human Response to Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1431 Vibration Perception
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1432 Frequency Weighting Curve
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1433 Iso-Perception Curves
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1434 Detection Threshold Curve
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 144 Regulation of Human Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1441 Acceptable Vibration Levels in Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1442 Whole-Body Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1443 HandndashArm Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
Page 12: Vibration Monitoring, Testing, and Instrumentationpreview.kingborn.net › 646000 › d1a74678d91943e5ba1d5e... · The MEMS Handbook, Second Edition MEMS: Introduction and Fundamentals

95 Practical Insights and Case Study 9-29

96 Conclusions 9-35

10 Vibration and Shock Problems of Civil Engineering Structures Priyan Mendis

and Tuan Ngo 10-1

101 Introduction 10-2

102 Earthquake-Induced Vibration of Structures 10-3

103 Dynamic Effects of Wind Loading on Structures 10-22

104 Vibrations Due to FluidndashStructure Interaction 10-33

105 Blast Loading and Blast Effects on Structures 10-34

106 Impact Loading 10-47

107 Floor Vibration 10-51

11 Seismic Base Isolation and Vibration Control Hirokazu Iemura Sarvesh Kumar Jain

and Mulyo Harris Pradono 11-1

111 Introduction 11-1

112 Seismic Base Isolation 11-4

113 Seismic Vibration Control 11-33

12 Seismic Random Vibration of Long-Span Structures Jiahao Lin and Yahui Zhang 12-1

121 Introduction 12-2

122 Seismic Random-Excitation Fields 12-11

123 Pseudoexcitation Method for Structural Random Vibration Analysis 12-16

124 Long-Span Structures Subjected to Stationary Random Ground Excitations 12-27

125 Long-Span Structures Subjected to Nonstationary Random Ground Excitations 12-34

126 Conclusions 12-39

13 Seismic Qualification of Equipment Clarence W de Silva 13-1

131 Introduction 13-1

132 Distribution Qualification 13-1

133 Seismic Qualification 13-6

14 Human Response to Vibration Clarence W de Silva 14-1

141 Introduction 14-1

142 Vibration Excitations on Humans 14-2

143 Human Response to Vibration 14-3

144 Regulation of Human Vibration 14-6

Contents xv

53191mdash1432007mdash1850mdashVELUmdash246493mdash CRC ndash pp 1ndash15

copy 2007 by Taylor amp Francis Group LLC

1Vibration

Instrumentation

Clarence W de SilvaThe University of British Columbia

11 Introduction 1-1

12 Vibration Exciters 1-3Shaker Selection dagger Dynamics of Electromagnetic Shakers

13 Control System 1-15Components of a Shaker Controller dagger Signal-Generating

Equipment

14 Performance Specification 1-21Parameters for Performance Specification dagger Linearity dagger

Instrument Ratings dagger Accuracy and Precision

15 Motion Sensors and Transducers 1-27Potentiometer dagger Variable-Inductance Transducers dagger

Mutual-Induction Proximity Sensor dagger Selfinduction

Transducers dagger Permanent-Magnet Transducers dagger

Alternating Current Permanent-Magnet Tachometer dagger

Alternating Current Induction Tachometer dagger Eddy Current

Transducers dagger Variable-Capacitance Transducers dagger

Piezoelectric Transducers

16 Torque Force and Other Sensors 1-50Strain Gage Sensors dagger Miscellaneous Sensors

Appendix 1A Virtual Instrumentation for DataAcquisition Analysis and Presentation 1-73

Summary

Devices useful in instrumenting a mechanical vibrating system are presented in this chapter Shakers whichgenerate vibration excitations are discussed and compared A variety of sensors including motion sensorsproximity sensors forcetorque sensors and other miscellaneous sensors are considered Performance specificationin the time domain and the frequency domain is addressed Rating parameters of instruments are given

11 Introduction

Measurement and associated experimental techniques play a significant role in the practice of vibration

Academic exposure to vibration instrumentation usually arises in laboratories in the context of learning

training and research In vibration practice perhaps the most important task of instrumentation is the

measurement or sensing of vibration Vibration sensing is useful in the following applications

1 Design and development of a product

2 Testing (screening) of a finished product for quality assurance

3 Qualification of a good-quality product to determine its suitability for a specific application

1-1

53191mdash522007mdash1201mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

4 Mechanical aging of a product prior to carrying out a test program

5 Exploratory testing of a product to determine its dynamic characteristics such as resonances

mode shapes and even a complete dynamic model

6 Vibration monitoring for performance evaluation

7 Control and suppression of vibration

Figure 11 indicates a procedure typical of experimental vibration highlighting the essential

instrumentation Vibrations are generated in a device the test object in response to some excitation In

some experimental procedures primarily in vibration testing (see Figure 11) the excitation signal has

to be generated in a signal generator in accordance with some requirement (specification) and applied to

the object through an exciter after amplification and conditioning In some other situations primarily in

performance monitoring and vibration control the excitations are generated as an integral part of the

operating environment of the vibrating object and may originate either within the object (eg engine

excitations in an automobile) or in the environment with which the object interacts during operation

(eg road disturbances on an automobile) Sensors are needed to measure vibrations in the test object In

particular a control sensor is used to check whether the specified excitation is applied to the object

and one or more response sensors may be used to measure the resulting vibrations at key locations of

the object

The sensor signals have to be properly conditioned for example by filtering and amplification and

modified for example through modulation demodulation and analog-to-digital conversion prior to

recording analyzing and display The purpose of the controller is to guarantee that the excitation is

correctly applied to the test object If the signal from the control sensor deviates from the required

excitation the controller modifies the signal to the exciter so as to reduce this deviation Furthermore the

controller will stabilize or limit (compress) the vibrations in the object It follows that instruments in

experimental vibration may be generally classified into the following categories

1 Signal-generating devices

2 Vibration exciters

3 Sensors and transducers

4 Signal conditioningmodifying devices

5 Signal analysis devices

6 Control devices

7 Vibration recording and display devices

AnalogDigital

Interface

DigitalSignal

RecorderAnalyzerDisplay

FilterAmplifier

FilterAmplifier

SignalGenerator

and ExciterController

Reference (Required)Signal (Specification)

PowerAmplifier

MountingFixtures

TestObject

ResponseSensor

ControlSensor

Exciter

SwivelBase

FIGURE 11 Typical instrumentation in experimental vibration

Vibration Monitoring Testing and Instrumentation1-2

53191mdash522007mdash1201mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

Note that one instrument may perform the tasks

of more than one category listed here Also more

than one instrument may be needed to carry out

tasks in a single category In the following sections

we will provide some examples of the types of

vibration instrumentation giving characteristics

operating principles and important practical

considerations Also we will describe several

experiments which can be found in a typical

vibration laboratory

An experimental vibration system generally

consists of four main subsystems

1 Test object

2 Excitation system

3 Control system

4 Signal acquisition and modification system

These are schematically shown in Figure 12 Note that various components shown in Figure 11 may

be incorporated into one of these subsystems In particular component matching hardware and object

mounting fixtures may be considered interfacing devices that are introduced through the interaction

between the main subsystems as shown in Figure 12 Some important issues of vibration testing and

instrumentation are summarized in Box 11

12 Vibration Exciters

Vibration experimentation may require an external exciter to generate the necessary vibration This is the

case in controlled experiments such as product testing where a specified level of vibration is applied to the

test object and the resulting response is monitored A variety of vibration exciters are available with

different capabilities and principles of operation

Three basic types of vibration exciters (shakers) are widely used hydraulic shakers inertial shakers

and electromagnetic shakers The operation-capability ranges of typical exciters in these three categories

are summarized in Table 11 Stroke or maximum displacement is the largest displacement the exciter

is capable of imparting onto a test object whose weight is assumed to be within its design load limit

Maximum velocity and acceleration are similarly defined Maximum force is the largest force that could

be applied by the shaker to a test object of acceptable weight (one within the design load) The values

given in Table 11 should be interpreted with caution Maximum displacement is achieved only at very

low frequencies The achievement of maximum velocity corresponds to intermediate frequencies in the

operating frequency range of the shaker Maximum acceleration and force ratings are usually achieved at

high frequencies It is not feasible for example to operate a vibration exciter at its maximum

displacement and its maximum acceleration simultaneously

Consider a loaded exciter that is executing harmonic motion Its displacement is given by

x frac14 s sin vt eth11THORN

in which s is the displacement amplitude (or stroke) Corresponding velocity and acceleration are

_x frac14 sv cos vt eth12THORN

eurox frac14 2sv2sin vt eth13THORN

SignalModification

System

TestObject

ControlSystem

VibrationExciter (Shaker)

System

FIGURE 12 Interactions between major subsystems of

an experimental vibration system

Vibration Instrumentation 1-3

53191mdash522007mdash1201mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

If the velocity amplitude is denoted by v and the acceleration amplitude by a it follows from Equation

12 and Equation 13 thatv frac14 vs eth14THORN

and

a frac14 vv eth15THORN

Box 11

VIBRATION INSTRUMENTATION

Vibration Testing Applications for Products

Design and Development Production Screening and Quality Assessment Utilization and Qualification for Special Applications

Testing Instrumentation

Exciter (excites the test object) Controller (controls the exciter for accurate excitation) Sensors and Transducers (measure excitations and responses and provide excitation error

signals to controller) Signal Conditioning (converts signals to appropriate form) Recording and Display (perform processing storage and documentation)

Exciters

Shakers

1 Electrodynamic (high bandwidth moderate power complex and multifrequency

excitations)

2 Hydraulic (moderate to high bandwidth high power complex and multifrequency

excitations)

3 Inertial (low bandwidth low power single-frequency harmonic excitations)

TransientInitial Condition

1 Hammers (impulsive bump tests)

2 Cable Release (step excitations)

3 Drop (impulsive)

Signal Conditioning

Filters Amplifiers Amplifiers ModulatorsDemodulators ADCDAC

Sensors

Motion (displacement velocity acceleration) Force (strain torque)

Vibration Monitoring Testing and Instrumentation1-4

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copy 2007 by Taylor amp Francis Group LLC

TABLE 11 Typical Operation-Capability Ranges for Various Shaker Types

Shaker Type Typical Operational Capabilities

Frequency Maximum Displacement

(Stroke)

Maximum

Velocity

Maximum

Acceleration

Maximum

Force

Excitation

Waveform

Hydraulic

(electrohydraulic)

Low

(01ndash500 Hz)

High (20 in 50 cm) Intermediate

(50 insec

125 cmsec)

Intermediate

(20 g)

High (100000 lbf

450000 N)

Average flexibility (simple

to complex and random)

Inertial

(counter-rotating mass)

Intermediate

(2ndash50 Hz)

Low (1 in 25 cm) Intermediate

(50 insec

125 cmsec)

Intermediate

(20 g)

Intermediate

(1000 lbf 4500 N)

Sinusoidal only

Electromagnetic

(electrodynamic)

High

(2ndash10000 Hz)

Low (1 in 25 cm) Intermediate

(50 insec

125 cmsec)

High (100 g) Low to intermediate

(450 lbf 2000 N)

High flexibility and accuracy

(simple to complex and

random)

VibrationInstru

mentation

1-5

53191mdash522007mdash

1201mdashSENTHILKUMARmdash246494mdash

CRCndashpp1ndash112

copy 2007 by Taylor amp Francis Group LLC

An idealized performance curve of a shaker

has a constant displacementndashamplitude region a

constant velocityndashamplitude region and a con-

stant accelerationndashamplitude region for low

intermediate and high frequencies respectively

in the operating frequency range Such an ideal

performance curve is shown in Figure 13(a) on a

frequencyndashvelocity plane Logarithmic axes are

used In practice typical shaker performance

curves would be fairly smooth yet nonlinear

curves similar to those shown in Figure 13(b)

As the mass increases the performance curve

compresses Note that the acceleration limit of a

shaker depends on the mass of the test object

(load) Full load corresponds to the heaviest object

that could be tested The ldquono loadrdquo condition

corresponds to a shaker without a test object To

standardize the performance curves they are

usually defined at the rated load of the shaker A

performance curve in the frequencyndashvelocity

plane may be converted to a curve in the

frequencyndashacceleration plane simply by increasing

the slope of the curve by a unit magnitude (ie

20 dbdecade)

Several general observations can be made from

Equation 14 and Equation 15 In the constant-

peak displacement region of the performance

curve the peak velocity increases proportionally

with the excitation frequency and the peak

acceleration increases with the square of the excitation frequency In the constant-peak velocity region

the peak displacement varies inversely with the excitation frequency and the peak acceleration increases

proportionately In the constant-peak acceleration region the peak displacement varies inversely with the

square of the excitation frequency and the peak velocity varies inversely with the excitation frequency

This further explains why rated stroke maximum velocity and maximum acceleration values are not

simultaneously realized

121 Shaker Selection

Vibration testing is accomplished by applying a specified excitation to the test package using a shaker

apparatus and monitoring the response of the test object Test excitation may be represented by its

response spectrum The test requires that the response spectrum of the actual excitation known as the

test response spectrum (TRS) envelops the response spectrum specified for the particular test known as

the required response spectrum (RRS)

A major step in the planning of any vibration testing program is the selection of a proper shaker

(exciter) system for a given test package The three specifications that are of primary importance in

selecting a shaker are the force rating the power rating and the stroke (maximum displacement) rating

Force and power ratings are particularly useful in moderate to high frequency excitations and the stroke

rating is the determining factor for low frequency excitations In this section a procedure is given to

determine conservative estimates for these parameters in a specified test for a given test package

Frequency domain considerations are used here

Stroke

Limit M

ax

Acceleration

MaxVelocity

Peak

Vel

ocity

(cm

s)

01 1 10 100

FullLoad

NoLoad

Frequency (Hz)(a)

Peak

Vel

ocity

(cm

s)

100

10

1

100

10

1

01 1 10 100

FullLoad

NoLoad

Frequency (Hz)(b)

FIGURE 13 Performance curve of a vibration exciter

in the frequencyndashvelocity plane (log) (a) ideal (b)

typical

Vibration Monitoring Testing and Instrumentation1-6

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copy 2007 by Taylor amp Francis Group LLC

1211 Force Rating

In the frequency domain the (complex) force at the exciter (shaker) head is given by

F frac14 mHethvTHORNasethvTHORN eth16THORNin which v is the excitation frequency variable m is the total mass of the test package including

mounting fixture and attachments asethvTHORN is the Fourier spectrum of the support-location (exciter head)

acceleration and H(v) is frequency response function that takes into account the flexibility and

damping effects (dynamics) of the test package apart from its inertia In the simplified case where the

test package can be represented by a simple oscillator of natural frequency vn and damping ratio by zt

this function becomes

HethvTHORN frac14 1thorn 2jztv=vn=12 ethv=vnTHORN2 thorn 2jztv=vn eth17THORNin which j frac14 ffiffiffiffi

21p

This approximation is adequate for most practical purposes The static weight of the

test object is not included in Equation 16 Most heavy-duty shakers which are typically hydraulic

have static load support systems such as pneumatic cushion arrangements that can exactly balance the

dead load The exciter provides only the dynamic force In cases where shaker directly supports the

gravity load in the vertical test configuration Equation 16 should be modified by adding a term to

represent this weight

A common practice in vibration test applications is to specify the excitation signal by its response

spectrum This is simply the peak response of a simple oscillator expressed as a function of its natural

frequency when its support location is excited by the specified signal Clearly the damping of the simple

oscillator is an added parameter in a response spectrum specification Typical damping ratios ethzrTHORN used inresponse spectra specifications are less than 01 (or 10) It follows that an approximate relationship

between the Fourier spectrum of the support acceleration and its response spectrum is

as frac14 2jzrarethvTHORN eth18THORNThe magnitude larethvTHORNl is the response spectrumEquation 18 substituted into Equation 16 gives

F frac14 mHethvTHORN2jzrarethvTHORN eth19THORNIn view of Equation 17 for test packages having low damping the peak value of H(v) is

approximately 1=eth2jztTHORN this should be used in computing the force rating if the test package has a

resonance within the frequency range of testing On the other hand if the test package is assumed to be

rigid then HethvTHORN oslash 1 A conservative estimate for the force rating is

Fmax frac14 methzr=ztTHORNlarethvTHORNlmax eth110THORNIt should be noted that larethvTHORNlmax is the peak value of the specified (required) response spectrum (RRS)

for acceleration

1212 Power Rating

The exciter head does not develop its maximum force when driven at maximum velocity Output power

is determined by using

p frac14 Refrac12FvsethvTHORN eth111THORNin which vsethvTHORN is the Fourier spectrum of the exciter velocity and Re [ ] denotes the real part of a complex

function Note that as frac14 jvvs Substituting Equation 16 and Equation 18 into Equation 111 gives

p frac14 eth4mz2r =vTHORNRefrac12jHethvTHORNa2r ethvTHORN eth112THORNIt follows that a conservative estimate for the power rating is

pmax frac14 2methz2r =ztTHORNfrac12larethvTHORNl2=v max eth113THORN

Vibration Instrumentation 1-7

53191mdash522007mdash1201mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

Representative segments of typical acceleration RRS curves have slope n as given by

a frac14 k1vn eth114THORN

It should be clear from Equation 113 that the maximum output power is given by

pmax frac14 k2v2n21 eth115THORN

This is an increasing function for n 1=2 and a decreasing function for n 1=2 It follows that the power

rating corresponds to the highest point of contact between the acceleration RRS curve and a line of slope

equal to 12 A similar relationship may be derived if velocity RRS curves (having slopes n2 1) are used

1213 Stroke Rating

From Equation 18 it should be clear that the Fourier spectrum xs of the exciter displacement time

history can be expressed as

xs frac14 2zrarethvTHORN=jv2 eth116THORNAn estimate for stroke rating is

xmax frac14 2zrfrac12larethvTHORNl=v2 max eth117THORNThis is of the form

xmax frac14 kvn22 eth118THORNIt follows that the stroke rating corresponds to the highest point of contact between the acceleration

RRS curve and a line of slope equal to two

Example 11

A test package of overall mass 100 kg is to be

subjected to dynamic excitation represented by the

acceleration RRS (at 5 damping) as shown in

Figure 14 The estimated damping of the test

package is 7 The test package is known to have a

resonance within the frequency range of the

specified test Determine the exciter specifications

for the test

Solution

From the development presented in the previous

section it is clear that the point F (or P) in

Figure 14 corresponds to the force and output

power ratings and the point S corresponds to

the stroke rating The co-ordinates of these

critical points are F P frac14 eth42 Hz 40 gTHORN and S frac14 eth08 Hz 075 gTHORN Equation 110 gives the force

rating as

Fmax frac14 100 pound eth005=007THORN pound 40 pound 981 N frac14 2803 N

Equation 113 gives the power rating as

pmax frac14 2 pound 100 pound eth0052=007THORN pound frac12eth40 pound 981THORN2=42 pound 2p watts frac14 417 W

Equation 117 gives the stroke rating as

xmax frac14 2 pound 005 pound frac12eth075 pound 98THORN=eth08 pound 2pTHORN2 m frac14 3 cm

Acc

eler

atio

n(g

)

Con

stan

t Dis

plac

emen

t

Constant Velo

city

Frequency (Hz)

S

FP

0101

10 10 100

10

10

FIGURE 14 Test excitation specified by an accelera-

tion RRS (5 damping)

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copy 2007 by Taylor amp Francis Group LLC

1214 Hydraulic Shakers

A typical hydraulic shaker consists of a piston-cylinder arrangement (also called a ram) a servo-valve a

fluid pump and a driving electric motor Hydraulic fluid (oil) is pressurized (typical operating pressure

4000 psi) and pumped into the cylinder through a servo-valve by means of a pump that is driven by an

electric motor (typical power 150 hp) The flow (typical rate 100 galmin) that enters the cylinder is

controlled (modulated) by the servo-valve which in effect controls the resulting piston (ram) motion

A typical servo-valve consists of a two-stage spool valve which provides a pressure difference and a

controlled (modulated) flow to the piston which sets it in motion

The servo-valve itself is moved by means of a linear torque motor which is driven by the excitation-

input signal (electrical) A primary function of the servo-valve is to provide a stabilizing feedback to the

ram In this respect the servo-valve complements the main control system of the test setup The ram is

coupled to the shaker table by means of a link with some flexibility The cylinder frame is mounted on the

support foundation with swivel joints This allows for some angular and lateral misalignment which

might be caused primarily by test-object dynamics as the table moves

Two-degree-of-freedom (Two-DoF) testing requires two independent sets of actuators and three-DoF

testing requires three independent actuator sets Each independent actuator set can consist of several

actuators operated in parallel using the same pump and the same excitation-input signal to the torque

motors

If the test table is directly supported on the vertical actuators they must withstand the total dead

weight (ie the weight of the test table the test object the mounting fixtures and the instrumentation)

This is requirement is usually prevented by providing a pressurized air cushion in the gap between the

test table and the foundation walls Air should be pressurized so as to balance the total dead weight

exactly (typical required gage pressure 3 psi)

Figure 15(a) shows the basic components of a typical hydraulic shaker The corresponding

operational block diagram is shown in Figure 15(b) It is desirable to locate the actuators in a pit in the

test laboratory so that the test tabletop is flushed with the test laboratory floor under no-load conditions

This minimizes the effort required to place the test object on the test table Otherwise the test object has

to be lifted onto the test table with a forklift Also installation of an aircushion to support the system

dead weight is difficult under these circumstances of elevated mounting

Hydraulic actuators are most suitable for heavy load testing and are widely used in industrial and civil

engineering applications They canbeoperated at very low frequencies (almost direct current [DC]) aswell

as at intermediate frequencies (see Table 11) Large displacements (stroke) are possible at low frequencies

Hydraulic shakers have the advantage of providing high flexibility of operation during the test their

capabilities include variable-force and constant-force testing and wide-band random-input testing The

velocity and acceleration capabilities of hydraulic shakers are moderate Although any general excitation-

input motion (for example sine wave sine beat wide-band random) can be used in hydraulic shakers

faithful reproduction of these signals is virtually impossible at high frequencies because of distortion and

higher-order harmonics introduced by the high noise levels that are common in hydraulic systems This

is only a minor drawback in heavy-duty intermediate-frequency applications Dynamic interactions are

reduced through feedback control

1215 Inertial Shakers

In inertial shakers or ldquomechanical excitersrdquo the force that causes the shaker-table motion is generated by

inertia forces (accelerating masses) Counter-rotating-mass inertial shakers are typical in this category

To understand their principle of operation consider two equal masses rotating in opposite directions at

the same angular speed v and in the same circle of radius r (see Figure 16) This produces a resultant

force equal to 2mv2r cos vt in a fixed direction (the direction of symmetry of the two rotating arms)

Consequently a sinusoidal force with a frequency of v and an amplitude proportional to v2 is generated

This reaction force is applied to the shaker table

Figure 17 shows a sketch of a typical counter-rotating-mass inertial shaker It consists of two identical

rods rotating at the same speed in opposite directions Each rod has a series of slots in which to

Vibration Instrumentation 1-9

53191mdash522007mdash1201mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

place weights In this manner the magnitude of

the eccentric mass can be varied to achieve various

force capabilities The rods are driven by a

variable-speed electric motor through a gear

mechanism that usually provides several speed

ratios A speed ratio is selected depending on the

required test-frequency range The whole system is

symmetrically supported on a carriage that is

directly connected to the test table The test object

is mounted on the test table The preferred

mounting configuration is horizontal so that the

excitation force is applied to the test object in a

horizontal direction In this configuration there

are no variable gravity moments (weight pounddistance to center of gravity) acting on the drive

mechanism Figure 17 shows the vertical con-

figuration In dynamic testing of large structures

the carriage can be mounted directly on the

structure at a location where the excitation force

should be applied By incorporating two pairs of

counter-rotating masses it is possible to generate

test moments as well as test forces

FIGURE 15 A typical hydraulic shaker arrangement (a) schematic diagram (b) operational block diagram

m m

2mw2r cos wt

wtw w

wt

FIGURE 16 Principle of operation of a counter-

rotating-mass inertial shaker

Vibration Monitoring Testing and Instrumentation1-10

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copy 2007 by Taylor amp Francis Group LLC

Reaction-type shakers driven by inertia are widely used for the prototype testing of civil engineering

structures Their first application dates back to 1935 Inertial shakers are capable of producing

intermediate excitation forces The force generated is limited by the strength of the carriage frame The

frequency range of operation and the maximum velocity and acceleration capabilities are also

intermediate for inertial shakers whereas the maximum displacement capability is typically low A major

limitation of inertial shakers is that their excitation force is exclusively sinusoidal and that the force

amplitude is directly proportional to the square of the excitation frequency As a result complex and

random excitation testing constant-force testing (for example transmissibility tests and constant-force

sine-sweep tests) and flexibility to vary the force amplitude or the displacement amplitude during a test

are not generally feasible with this type of shakers Excitation frequency and amplitude can be varied

during testing however by incorporating a variable-speed drive for the motor The sinusoidal excitation

generated by inertial shakers is virtually undistorted which gives them an advantage over the other types

of shakers when used in sine-dwell and sine-sweep tests Small portable shakers with low-force capability

are available for use in on-site testing

1216 Electromagnetic Shakers

In electromagnetic shakers or ldquoelectrodynamic excitersrdquo the motion is generated using the principle of

operation of an electric motor Specifically the excitation force is produced when a variable excitation

signal (electrical) is passed through a moving coil placed in a magnetic field

The components of a commercial electromagnetic shaker are shown in Figure 18 A steady magnetic

field is generated by a stationary electromagnet that consists of field coils wound on a ferromagnetic base

that is rigidly attached to a protective shell structure The shaker head has a coil wound around it When

the excitation electrical signal is passed through this drive coil the shaker head which is supported on

flexure mounts will be set in motion The shaker head consists of the test table on which the test object

is mounted Shakers with interchangeable heads are available The choice of appropriate shaker head is

based on the geometry and mounting features of the test object The shaker head can be turned to

different angles by means of a swivel joint In this manner different directions of excitation (in biaxial

and triaxial testing) can be obtained

FIGURE 17 Sketch of a counter-rotating-mass inertial shaker

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copy 2007 by Taylor amp Francis Group LLC

122 Dynamics of Electromagnetic Shakers

Consider a single axis electromagnetic shaker (Figure 18) with a test object having a single natural

frequency of importance within the test frequency range The dynamic interactions between the shaker

and the test object give rise to two significant natural frequencies (and correspondingly two significant

resonances) These appear as peaks in the frequency response curve of the test setup Furthermore the

natural frequency (resonance) of the test package alone causes a ldquotroughrdquo or depression (antiresonance)

in the frequency response curve of the overall test setup To explain this characteristic consider the

dynamic model shown in Figure 19 The following mechanical parameters are defined for

Figure 19(a) m k and b are the mass stiffness and equivalent viscous damping constant respectively

of the test package and me ke and be are the corresponding parameters of the exciter (shaker) Also in

the equivalent electrical circuit of the shaker head as shown in Figure 19(b) the following electrical

parameters are defined Re and Le are the resistance and (leakage) inductance and kb is the back

electromotive force (back emf) of the linear motor Assuming that the gravitational forces are supported

FIGURE 18 Schematic sectional view of a typical electromagnetic shaker manufactured by Bruel and Kjaer

Denmark

Vibration Monitoring Testing and Instrumentation1-12

53191mdash522007mdash1202mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

by the static deflections of the flexible elements and that the displacements are measured from the static

equilibrium position we have the following system equations

Test object meuroy frac14 2kethy2 yeTHORN2 beth_y2 _yeTHORN eth119THORNShaker head me euroye frac14 fe thorn kethy2 yeTHORN thorn beth_y2 _yeTHORN2 key 2 be _ye eth120THORN

Electrical Lediedt

thorn Reie thorn kb _ye frac14 vethtTHORN eth121THORN

The electromagnetic force fe generated in the shaker head is a result of the interaction of the magnetic

field generated by the current ie with coil of the moving shaker head and the constant magnetic field

(stator) in which the head coil is located Here we have

fe frac14 kbie eth122THORNNote that v(t) is the voltage signal that is applied by the amplifier to the shaker coil ye is the displacement

of the shaker head and y is the displacement response of the test package

It is assumed that kb has consistent electrical and mechanical units (Vmsec and NA) Usually

the electrical time constant of the shaker is quite small compared with the primarily mechanical

time constants of the shaker and the test package In such cases the Ledie=dt term in Equation 121 may

be neglected Consequently the equations from Equation 119 through Equation 122 may be

expressed in the Laplace (frequency) domain with the Laplace variable s taking the place of the derivative

d=dt as

ethms2 thorn bsthorn kTHORNy frac14 ethbsthorn kTHORNye eth123THORN

FIGURE 19 Dynamic models of an electromagnetic shaker and a flexible test package (a) mechanical model

(b) electrical model

Vibration Instrumentation 1-13

53191mdash522007mdash1202mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

frac12mes2 thorn ethbthorn beTHORNsthorn ethkthorn keTHORN ye frac14 ethbsthorn kTHORNy thorn kb

Rev2

k2bs

Reye eth124THORN

It follows that the transfer function of the shaker head motion with respect to the excitation voltage is

given by

yevfrac14 kb

Re

DethsTHORNDdethsTHORN eth125THORN

where DethsTHORN is the characteristic function of the primary dynamics of the test object

DethsTHORN frac14 ms2 thorn bsthorn k eth126THORN

and DdethsTHORN is the characteristic function of the primary dynamic interactions between the shaker and thetest object

DcethsTHORN frac14 mmes4 thorn frac12methbe thorn bthorn boTHORN thornmeb s

3 thorn frac12methke thorn kTHORN thornmekthorn bethbe thorn boTHORN s2thorn frac12bke thorn ethbe thorn boTHORNk sthorn kke

eth127THORN

where

bo frac14 k2bRe

eth128THORN

It is clear that under low damping conditions DdethsTHORN will produce two resonances as it is fourth order in sand similarly DethsTHORN will produce one antiresonance (trough) corresponding to the resonance of the testobject Note that in the frequency domain s frac14 jv and hence the frequency response function given by

Equation 125 is in fact

yevfrac14 kb

Rb

DethjvTHORNDdethjvTHORN eth129THORN

The magnitude of this frequency response function for a typical test system is sketched in Figure 110

Note that this curve is for the ldquoopen-looprdquo case where there is no feedback from the shaker controller

In practice the shaker controller will be able

to compensate for the resonances and anti-

resonances to some degree depending on its

effectiveness

The main advantages of electromagnetic

shakers are their high frequency range of

operation their high degree of operating flexi-

bility and the high level of accuracy of the

generated shaker motion Faithful reproduction

of complex excitations is possible because of the

advanced electronics and control systems used in

this type of shakers Electromagnetic shakers are

not suitable for heavy-duty applications (large test

objects) however High test-input accelerations

are possible at high frequencies when electromag-

netic shakers are used but their displacement and

velocity capabilities are limited to low or

intermediate values (see Table 11)

100

10

1 10 100Excitation Frequency (Hz)

Antiresonance

Resonance

Shak

erD

ispl

acem

entM

agni

tude

Resonance

1000

FIGURE 110 Frequency response curve of a typical

electromagnetic shaker with a test object

Vibration Monitoring Testing and Instrumentation1-14

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copy 2007 by Taylor amp Francis Group LLC

1221 Transient Exciters

Other varieties of exciters are commonly used in

transient-type vibration testing In these tests

either an impulsive force or an initial excitation is

applied to the test object and the resulting

response is monitored The excitations and the

responses are ldquotransientrdquo in this case Hammer

test drop tests and pluck tests fall into this

category For example a hammer test may be

conducted by hitting the object with an instru-

mented hammer and then measuring the response

of the object The hammer has a force sensor at its

tip as sketched in Figure 111 A piezoelectric or

strain-gage type force sensor may be used More

sophisticated hammers have impedance heads in

place of force sensors An impedance head

measures force and acceleration simultaneously

The results of a hammer test will depend on many

factors for example the dynamics of the hammer

body how firmly the hammer is held during the

impact how quickly the impact is applied and

whether there are multiple impacts

13 Control System

The two primary functions of the shaker control system in vibration testing are (1) to guarantee that the

specified excitation is applied to the test object and (2) to ensure that the dynamic stability (motion

constraints) of the test setup is preserved An operational block diagram illustrating these control

functions is given in Figure 112 The reference input to the control system represents the desired

excitation force that should be applied to the test object In the absence of any control however the force

reaching the test object will be distorted primarily because of (1) dynamic interactions and

nonlinearities of the shaker the test table the mounting fixtures the auxiliary instruments and the test

object itself (2) noise and errors in the signal generator amplifiers filters and other equipment and (3)

external loads and disturbances acting on the test object and other components (for example external

restraints aerodynamic forces friction) To compensate for these distorting factors response

measurements (displacements velocities acceleration and so on) are made at various locations in the

test setup and are used to control the system dynamics In particular the responses of the shaker the test

table and the test object are measured These responses are used to compare the actual excitation felt by

FIGURE 111 An instrumented hammer used in bump

tests or hammer tests

ExcitationInput

(Reference)

Feedback Paths

DriveSignal

ShakerResponse

TestTable

TestObject

Test ObjectResponse

Test TableResponseExciter

(Shaker)(Ram)

Controllerand

Amplifier

FIGURE 112 Operational block diagram illustrating a general shaker control system

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copy 2007 by Taylor amp Francis Group LLC

the test object at the shaker interface with the desired (specified) input The drive signal to the shaker is

modified depending on the error that is present

Two types of control are commonly employed in shaker apparatus simple manual control and

complex automatic control Manual control normally consists of simple open-loop trial-and-error

methods of manual adjustments (or calibration) of the control equipment to obtain a desired dynamic

response The actual response is usually monitored (on an oscilloscope or frequency analyzer screen for

example) during manual-control operations The pretest adjustments in manual control can be very

time-consuming as a result the test object might be subjected to overtesting which could produce

cumulative damage is undesirable and could defeat the test purpose Furthermore the calibration

procedure for the experimental setup must be repeated for each new test object

The disadvantages ofmanual control suggest that automatic control is desirable in complex test schemes

in which high accuracy of testing is desired The first step of automatic control involves automatic

measurement of the system response using control sensors and transducers The measurement is then fed

back into the control system which instantaneously determines the best drive signal to actuate the shaker

in order to get the desired excitation This may be done by either analog or digital methods

Primitive control systems require an accurate mathematical description of the test object This

dependency of the control system on the knowledge of test-object dynamics is clearly undesirable

Performance of a good control system should not be considerably affected by the dynamic interactions

and nonlinearities of the test object or by the nature of the excitation Proper selection of feedback signals

and control-system components can reduce such effects and will make the system robust

In the response-spectrum method of vibration testing it is customary to use displacement control at

low frequencies velocity control at intermediate frequency and acceleration control at high frequencies

This necessitates feedback of displacement velocity and acceleration responses Generally however the

most important feedback is the velocity feedback In sine-sweep tests the shaker velocity must change

steadily over the frequency band of interest In particular the velocity control must be precise near the

resonances of the test object Velocity (speed) feedback has a stabilizing effect on the dynamics which is

desirable This effect is particularly useful in ensuring stability in motion when testing is done near

resonances of lightly damped test objects On the contrary displacement (position) feedback can have a

destabilizing effect on some systems particularly when high feedback gains are used

The controller usually consists of various instruments equipment and computation hardware and

software Often the functions of the data-acquisition and processing system overlap with those of the

controller to some extent As an example consider the digital-controller of vibration testing apparatus

First the responses are measured through sensors (and transducers) filtered and amplified

(conditioned) These data channels may be passed through a multiplexer whose purpose is to select

one data channel at a time for processing Most modern data acquisition hardware does not need a

separate multiplexer to handle multiple signals The analog data are converted into digital data using

analog-to-digital converters (ADCs) The resulting sampled data are stored on a disk or as a block data in

the computer memory The reference input signal (typically a signal recorded on an FM tape) is also

sampled (if it is not already in the digital form) using an ADC and fed into the computer Digital

processing is done on the reference signal and the response data with the objective of computing the

command signal to drive the shaker The digital command signal is converted into an analog signal using

a digital-to-analog converter (DAC) and amplified (conditioned) before it is used to drive the exciter

The nature of the control components depends to a large extent on the nature and objectives of the

particular test to be conducted Some of the basic components in a shaker controller are described in

the following subsections

131 Components of a Shaker Controller

1311 Compressor

A compressor circuit is incorporated in automatic excitation control devices to control the excitation-

input level automatically The level of control depends on the feedback signal from a control sensor and

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the specified (reference) excitation signal Usually the compressor circuit is included in the excitation-

signal generator (for example in a sine generator) The control by this means may be done on the basis of

a single-frequency component (eg the fundamental frequency)

1312 Equalizer (Spectrum Shaper)

Random-signal equalizers are used to shape the spectrum of a random signal in a desired manner In

essence and equalizer consists of a bank of narrow-band filters (for example 80 filters) in parallel over

the operating frequency range By passing the signal through each filter the spectral density (or the mean

square value) of the signal in that narrow frequency band (for example each one-third-octave band) is

determined This is compared with the desired spectral level and automatic adjustment is made in that

filter in case there is an error In some systems response-spectrum analysis is made in place of power

spectral density analysis In that case the equalizer consists of a bank of simple oscillators whose

resonant frequencies are distributed over the operating frequency range of the equalizer The feedback

signal is passed through each oscillator and the peak value of its output is determined This value is

compared with the desired response spectrum value at that frequency If there is an error automatic gain

adjustment is made in the appropriate excitation signal components

Random-noise equalizers are used in conjunction with random signal generators They receive

feedback signals from the control sensors In some digital control systems there are algorithms (software)

that are used to iteratively converge the spectrum of the excitation signal felt by the test object into the

desired spectrum

1313 Tracking Filter

Many vibration tests are based on single-frequency excitations In such cases the control functions

should be performed on the basis of the amplitudes of the fundamental-frequency component of the

signal A tracking filter is simply a frequency-tuned band-pass filter It automatically tunes the center

frequency of its very narrow-band-pass filter to the frequency of a carrier signal Then when a noisy

signal is passed through the tuned filter the output of the filter will be the required fundamental

frequency component in the signal Tracking filters also are useful in obtaining amplitudendashfrequency

plots using an XndashY plotter In such cases the frequency value comes from the signal generator (sweep

oscillator) which produces the carrier signal to the tracking filter The tracking filter then determines the

corresponding amplitude of a signal that is fed into it Most tracking filters have dual channels so that two

signals can be handled (tracked) simultaneously

1314 Excitation Controller (Amplitude Servo-Monitor)

An excitation controller is typically an integral part of the signal generator It can be set so that automatic

sweep between two frequency limits can be performed at a selected sweep rate (linear or logarithmic)

More advanced excitation controllers have the capability of an automatic switch-over between constant-

displacement constant-velocity and constant-acceleration excitation-input control at specified

frequencies over the sweep frequency interval Consequently integrator circuits should be present

within the excitation controller unit to determine velocities and displacements from acceleration signals

Sometimes integration is performed by a separate unit called a vibration meter This unit also offers

the operator the capability of selecting the desired level of each signal (acceleration velocity or

displacement) There is an automatic cut-off level for large displacement values that could result from

noise in acceleration signals A compressor is also a subcomponent of the excitation controller The

complete unit is sometimes known as an amplitude servo-monitor

132 Signal-Generating Equipment

Shakers are force-generating devices that are operated using drive (excitation) signals generated from a

source The excitation-signal source is known as the signal generator Three major types of signal

generators are used in vibration testing applications (1) oscillators (2) random-signal generators and

(3) storage devices In some units oscillators and random-signal generators are combined We shall

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discuss these two generators separately however because of their difference in function It also should be

noted that almost any digital signal (deterministic or random) can be generated by a digital computer

using a suitable computer program the signal eventually can be passed through a DAC to obtain

the corresponding analog signal These lsquodigitalrsquo signal generators along with analog sources such as

magnetic tape players (FM) are classified into the category of storage devices

The dynamic range of equipment is the ratio of the maximum and minimum output levels (expressed

in decibels) at which it is capable of operating without significant error This is an important specification

for many types of equipment particularly for signal-generating devices The output level of the signal

generator should be set to a value within its dynamic range

1321 Oscillators

Oscillators are essentially single-frequency generators Typically sine signals are generated but other

waveforms (such as rectangular and triangular pulses) are also available in most oscillators Normally

an oscillator has two modes of operation (1) sweeping up and down between two frequency limits and

(2) dwelling at a specified frequency In the sweep operation the sweep rate should be specified This can

be done either on a linear scale (Hzmin) or on a logarithmic scale (octavesmin) In the dwell operation

the frequency points (or intervals) should be specified In either case a desired signal level can be chosen

using the gain-control knob An oscillator that is operated exclusively in the sweep mode is called a sweep

oscillator

The early generation of oscillators employed variable inductor-capacitor types of electronic circuits to

generate signals oscillating at a desired frequency The oscillator is tuned to the required frequency by

varying the capacitance or inductance parameters A DC voltage is applied to energize the capacitor

and to obtain the desired oscillating voltage signal which subsequently is amplified and conditioned

Modern oscillators use operational amplifier circuits along with resistor capacitor and semiconductor

(SC) elements Also common are crystal (quartz) parallel-resonance oscillators used to generate voltage

signals accurately at a fixed frequency The circuit is activated using a DC-voltage source Other

frequencies of interest are obtained by passing this high-frequency signal through a frequency converter

The signal is then conditioned (amplified and filtered) Required shaping (for example rectangular

pulse) is obtained using a shape circuit Finally the required signal level is obtained by passing the

resulting signal through a variable-gain amplifier A block diagram of an oscillator illustrating various

stages in the generation of a periodic signal is given in Figure 113

A typical oscillator offers a choice of several (typically six) linear and logarithmic frequency ranges and

a sizable level of control capability (for example 80 dB) Upper and lower frequency limits in a sweep can

be preset on the front panel to any of the available frequency ranges Sweep-rate settings are continuously

DC Voltage

Oscillator

FrequencySpecification

FrequencyConverter

FilterAmplifier

ShaperPeriodicSignal

FrequencyCounter

Fixed-FrequencySignal

Variable-GainOutput

Amplifier

SignalSpecification

LevelSpecification

FIGURE 113 Block diagram of an oscillator-type signal generator

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  • 53191fm
    • Vibration Monitoring Testing and Instrumentation
      • Preface
      • Acknowledgments
      • Editor-in-Chief
      • Contributors
      • Contents
      • Related Titles
          • 53191ch1
            • Table of Contents
            • Chapter 1 Vibration Instrumentation
              • Summary
              • 11 Introduction
              • 12 Vibration Exciters
                • 121 Shaker Selection
                  • 1211 Force Rating
                  • 1212 Power Rating
                  • 1213 Stroke Rating
                  • 1214 Hydraulic Shakers
                  • 1215 Inertial Shakers
                  • 1216 Electromagnetic Shakers
                    • 122 Dynamics of Electromagnetic Shakers
                      • 1221 Transient Exciters
                          • 13 Control System
                            • 131 Components of a Shaker Controller
                              • 1311 Compressor
                              • 1312 Equalizer (Spectrum Shaper)
                              • 1313 Tracking Filter
                              • 1314 Excitation Controller (Amplitude Servo-Monitor)
                                • 132 Signal-Generating Equipment
                                  • 1321 Oscillators
                                  • 1322 Random Signal Generators
                                  • 1323 Tape Players
                                  • 1324 Data Processing
                                      • 14 Performance Specification
                                        • 141 Parameters for Performance Specification
                                          • 1411 Time-Domain Specifications
                                          • 1412 Frequency-Domain Specifications
                                            • 142 Linearity
                                            • 143 Instrument Ratings
                                              • 1431 Rating Parameters
                                                • 144 Accuracy and Precision
                                                  • 15 Motion Sensors and Transducers
                                                    • 151 Potentiometer
                                                      • 1511 Potentiometer Resolution
                                                      • 1512 Optical Potentiometer
                                                        • 152 Variable-Inductance Transducers
                                                          • 1521 Mutual-Induction Transducers
                                                          • 1522 Linear-Variable Differential Transformer
                                                          • 1523 Signal Conditioning
                                                            • 153 Mutual-Induction Proximity Sensor
                                                            • 154 Selfinduction Transducers
                                                            • 155 Permanent-Magnet Transducers
                                                            • 156 Alternating Current Permanent-Magnet Tachometer
                                                            • 157 Alternating Current Induction Tachometer
                                                            • 158 Eddy Current Transducers
                                                            • 159 Variable-Capacitance Transducers
                                                              • 1591 Capacitive Displacement Sensors
                                                              • 1592 Capacitive Angular Velocity Sensor
                                                              • 1593 Capacitance Bridge Circuit
                                                                • 1510 Piezoelectric Transducers
                                                                  • 15101 Sensitivity
                                                                  • 15102 Piezoelectric Accelerometer
                                                                  • 15103 Charge Amplifier
                                                                      • 16 Torque Force and Other Sensors
                                                                        • 161 Strain Gage Sensors
                                                                          • 1611 Equations for Strain Gage Measurements
                                                                          • 1612 Bridge Sensitivity
                                                                          • 1613 The Bridge Constant
                                                                          • 1614 The Calibration Constant
                                                                          • 1615 Data Acquisition
                                                                          • 1616 Accuracy Considerations
                                                                          • 1617 Semiconductor Strain Gages
                                                                          • 1618 Force and Torque Sensors
                                                                          • 1619 Strain Gage Torque Sensors
                                                                          • 16110 Deflection Torque Sensors
                                                                          • 16111 Variable-Reluctance Torque Sensor
                                                                          • 16112 Reaction Torque Sensors
                                                                            • 162 Miscellaneous Sensors
                                                                              • 1621 Stroboscope
                                                                              • 1622 Fiber Optic Sensors and Lasers
                                                                              • 1623 Fiber-Optic Gyroscope
                                                                              • 1624 Laser Doppler Interferometer
                                                                              • 1625 Ultrasonic Sensors
                                                                              • 1626 Gyroscopic Sensors
                                                                                  • References
                                                                                  • Appendix 1A Virtual Instrumentation for Data Acquisition Analysis and Presentation
                                                                                    • Summary
                                                                                    • List of Abbreviations
                                                                                    • 1A1 Dynamic Signals
                                                                                      • 1A11 Acquiring and Simulating Dynamic Signals
                                                                                        • 1A111 Aliasing
                                                                                        • 1A112 Time Continuity
                                                                                            • 1A2 Measurement Configuration Considerations
                                                                                              • 1A21 Input Signal Considerations
                                                                                                • 1A211 Input Pseudodifferential and Differential Configuration
                                                                                                • 1A212 Gain
                                                                                                • 1A213 Input Coupling
                                                                                                • 1A214 Integrated Electronic Piezoelectric Excitation
                                                                                                • 1A215 Nyquist Frequency and Bandwidth
                                                                                                • 1A216 Analog-to-Digital Conversion
                                                                                                • 1A217 Antialias Filters
                                                                                                • 1A218 Input Filter Delay
                                                                                                • 1A219 Overload Detection
                                                                                                  • 1A22 Output Signal Considerations
                                                                                                    • 1A221 Output Pseudodifferential and Differential Configuration
                                                                                                    • 1A222 Attenuation
                                                                                                    • 1A223 Digital-to-Analog Conversion
                                                                                                    • 1A224 Anti-imaging and Interpolation Filters
                                                                                                    • 1A225 Output Filter Delay
                                                                                                        • 1A3 Scaling and Calibration
                                                                                                          • 1A31 Scaling to Engineering Units
                                                                                                          • 1A32 Performing System Calibration
                                                                                                            • 1A321 Propagation Delay Calibration
                                                                                                                • 1A4 Limit Testing Analysis
                                                                                                                  • 1A41 Limit Testing Overview
                                                                                                                  • 1A42 Using the SVT Limit Testing VI
                                                                                                                    • 1A5 Integration
                                                                                                                      • 1A51 Introduction to Integration
                                                                                                                      • 1A52 Implementing Integration
                                                                                                                        • 1A521 Challenges when Integrating Vibration Data
                                                                                                                          • 1A53 Time-Domain Integration
                                                                                                                            • 1A531 Single-Shot Acquisition and Integration
                                                                                                                            • 1A532 Continuous Acquisition and Integration
                                                                                                                              • 1A54 Frequency-Domain Integration
                                                                                                                                • 1A6 Vibration-Level Measurements
                                                                                                                                  • 1A61 Measuring the Root Mean Square Level
                                                                                                                                    • 1A611 Single-Shot Buffered Acquisition
                                                                                                                                    • 1A612 Continuous Signal Acquisition
                                                                                                                                      • 1A62 Performing a Running RMS Level Measurement
                                                                                                                                      • 1A63 Computing the Peak Level
                                                                                                                                      • 1A64 Computing the Crest Factor
                                                                                                                                        • 1A7 Frequency Analysis
                                                                                                                                          • 1A71 FFT Fundamentals
                                                                                                                                            • 1A711 Number of Samples
                                                                                                                                            • 1A712 Frequency Resolution
                                                                                                                                            • 1A713 Maximum Resolvable Frequency
                                                                                                                                            • 1A714 Minimum Resolvable Frequency
                                                                                                                                            • 1A715 Number of Spectral Lines
                                                                                                                                            • 1A716 Relationship between Time-Domain and Frequency-Domain Specifications and Parameters
                                                                                                                                              • 1A72 Increasing Frequency Resolution
                                                                                                                                                • 1A721 Zoom FFT Analysis
                                                                                                                                                • 1A722 Frequency Resolution of the Zoom FFT VIs
                                                                                                                                                • 1A723 Zoom Measurement
                                                                                                                                                • 1A724 Zoom Settings
                                                                                                                                                • 1A725 Subset Analysis
                                                                                                                                                    • 1A8 Transient Analysis
                                                                                                                                                      • 1A81 Transient Analysis with the Sound and Vibration Toolkit
                                                                                                                                                      • 1A82 Performing an STFT vs Time
                                                                                                                                                        • 1A821 Selecting the FFT Block Size
                                                                                                                                                        • 1A822 Overlapping
                                                                                                                                                        • 1A823 Using the SVT STFT vs Time VI
                                                                                                                                                          • 1A83 Performing an STFT vs Rotational Speed
                                                                                                                                                            • 1A831 Converting the Pulse Train to Rotational Speed
                                                                                                                                                            • 1A832 STFT vs RPM
                                                                                                                                                              • 1A84 Measuring a Shock Response Spectrum
                                                                                                                                                                • 1A9 Waterfall Display
                                                                                                                                                                  • 1A91 Using the Display VIs
                                                                                                                                                                    • 1A911 Initializing the Display
                                                                                                                                                                    • 1A912 Sending Data to the Display
                                                                                                                                                                    • 1A913 Waterfall Display for Frequency Analysis
                                                                                                                                                                    • 1A914 Waterfall Display for Transient Analysis
                                                                                                                                                                    • 1A915 Waterfall Display for Octave Spectra
                                                                                                                                                                        • 1A10 Swept-Sine Measurements
                                                                                                                                                                          • 1A101 Swept-Sine Overview
                                                                                                                                                                          • 1A102 Choosing Swept-Sine vs FFT Measurements
                                                                                                                                                                          • 1A103 Taking a Swept-Sine Measurement
                                                                                                                                                                          • 1A104 Swept-Sine Measurement Example
                                                                                                                                                                              • Bibliography
                                                                                                                                                                              • Related Titles
                                                                                                                                                                                  • 53191ch2
                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                    • Chapter 2 Signal Conditioning and Modification
                                                                                                                                                                                      • Summary
                                                                                                                                                                                      • 21 Introduction
                                                                                                                                                                                      • 22 Amplifiers
                                                                                                                                                                                        • 221 Operational Amplifier
                                                                                                                                                                                        • 222 Use of Feedback in Opamp
                                                                                                                                                                                        • 223 Voltage Current and Power Amplifiers
                                                                                                                                                                                          • 2231 Charge Amplifiers
                                                                                                                                                                                            • 224 Instrumentation Amplifiers
                                                                                                                                                                                              • 2241 Differential Amplifier
                                                                                                                                                                                              • 2242 Common Mode
                                                                                                                                                                                                • 225 Amplifier Performance Ratings
                                                                                                                                                                                                  • 2251 Common-Mode Rejection Ratio
                                                                                                                                                                                                    • 226 Component Interconnection
                                                                                                                                                                                                      • 2261 Impedance Characteristics
                                                                                                                                                                                                      • 2262 Cascade Connection of Devices
                                                                                                                                                                                                      • 2263 AC-Coupled Ampliers
                                                                                                                                                                                                          • 23 Analog Filters
                                                                                                                                                                                                            • 231 Passive Filters and Active Filters
                                                                                                                                                                                                              • 2311 Number of Poles
                                                                                                                                                                                                                • 232 Low-Pass Filters
                                                                                                                                                                                                                  • 2321 Low-Pass Butterworth Filter
                                                                                                                                                                                                                    • 233 High-Pass Filters
                                                                                                                                                                                                                    • 234 Band-Pass Filters
                                                                                                                                                                                                                      • 2341 Resonance-Type Band-Pass Filters
                                                                                                                                                                                                                        • 235 Band-Reject Filters
                                                                                                                                                                                                                          • 24 Modulators and Demodulators
                                                                                                                                                                                                                            • 241 Amplitude Modulation
                                                                                                                                                                                                                              • 2411 Modulation Theorem
                                                                                                                                                                                                                              • 2412 Side Frequencies and Side Bands
                                                                                                                                                                                                                                • 242 Application of Amplitude Modulation
                                                                                                                                                                                                                                  • 2421 Fault Detection and Diagnosis
                                                                                                                                                                                                                                    • 243 Demodulation
                                                                                                                                                                                                                                      • 25 Analog ndashDigital Conversion
                                                                                                                                                                                                                                        • 251 Digital-to-Analog Conversion
                                                                                                                                                                                                                                          • 2511 DAC Error Sources
                                                                                                                                                                                                                                            • 252 Analog-to-Digital Conversion
                                                                                                                                                                                                                                            • 253 Analog-to-Digital Converter Performance Characteristics
                                                                                                                                                                                                                                              • 2531 Resolution and Quantization Error
                                                                                                                                                                                                                                              • 2532 Monotonicity Nonlinearity and Offset Error
                                                                                                                                                                                                                                              • 2533 Analog-to-Digital Converter Conversion Rate
                                                                                                                                                                                                                                                • 254 Sample-and-Hold Circuitry
                                                                                                                                                                                                                                                • 255 Digital Filters
                                                                                                                                                                                                                                                  • 2551 Software Implementation and Hardware Implementation
                                                                                                                                                                                                                                                      • 26 Bridge Circuits
                                                                                                                                                                                                                                                        • 261 Wheatstone Bridge
                                                                                                                                                                                                                                                        • 262 Constant-Current Bridge
                                                                                                                                                                                                                                                        • 263 Bridge Amplifiers
                                                                                                                                                                                                                                                          • 2631 Half-Bridge Circuits
                                                                                                                                                                                                                                                            • 264 Impedance Bridges
                                                                                                                                                                                                                                                              • 2641 Owen Bridge
                                                                                                                                                                                                                                                              • 2642 Wien-Bridge Oscillator
                                                                                                                                                                                                                                                                  • 27 Linearizing Devices
                                                                                                                                                                                                                                                                    • 271 Linearization by Software
                                                                                                                                                                                                                                                                    • 272 Linearization by Hardware Logic
                                                                                                                                                                                                                                                                    • 273 Analog Linearizing Circuitry
                                                                                                                                                                                                                                                                    • 274 Offsetting Circuitry
                                                                                                                                                                                                                                                                    • 275 Proportional-Output Circuitry
                                                                                                                                                                                                                                                                      • 2751 Curve-Shaping Circuitry
                                                                                                                                                                                                                                                                          • 28 Miscellaneous Signal Modification Circuitry
                                                                                                                                                                                                                                                                            • 281 Phase Shifters
                                                                                                                                                                                                                                                                            • 282 Voltage-to-Frequency Converter
                                                                                                                                                                                                                                                                            • 283 Frequency-to-Voltage Converter
                                                                                                                                                                                                                                                                            • 284 Voltage-to-Current Converters
                                                                                                                                                                                                                                                                            • 285 Peak-Hold Circuits
                                                                                                                                                                                                                                                                              • 29 Signal Analyzers and Display Devices
                                                                                                                                                                                                                                                                                • 291 Signal Analyzers
                                                                                                                                                                                                                                                                                • 292 Oscilloscopes
                                                                                                                                                                                                                                                                                  • 2921 Triggering
                                                                                                                                                                                                                                                                                  • 2922 Lissajous Patterns
                                                                                                                                                                                                                                                                                  • 2923 Digital Oscilloscopes
                                                                                                                                                                                                                                                                                      • Bibliography
                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                          • 53191ch3
                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                            • Chapter 3 Vibration Testing
                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                              • 31 Introduction
                                                                                                                                                                                                                                                                                              • 32 Representation of a Vibration Environment
                                                                                                                                                                                                                                                                                                • 321 Test Signals
                                                                                                                                                                                                                                                                                                  • 3211 Stochastic vs Deterministic Signals
                                                                                                                                                                                                                                                                                                    • 322 Deterministic Signal Representation
                                                                                                                                                                                                                                                                                                      • 3221 Single-Frequency Signals
                                                                                                                                                                                                                                                                                                      • 3222 Sine Sweep
                                                                                                                                                                                                                                                                                                      • 3223 Sine Dwell
                                                                                                                                                                                                                                                                                                      • 3224 Decaying Sine
                                                                                                                                                                                                                                                                                                      • 3225 Sine Beat
                                                                                                                                                                                                                                                                                                      • 3226 Sine Beat with Pauses
                                                                                                                                                                                                                                                                                                      • 3227 Multifrequency Signals
                                                                                                                                                                                                                                                                                                      • 3228 Actual Excitation Records
                                                                                                                                                                                                                                                                                                      • 3229 Simulated Excitation Signals
                                                                                                                                                                                                                                                                                                        • 323 Stochastic Signal Representation
                                                                                                                                                                                                                                                                                                          • 3231 Ergodic Random Signals
                                                                                                                                                                                                                                                                                                          • 3232 Stationary Random Signals
                                                                                                                                                                                                                                                                                                          • 3233 Independent and Uncorrelated Signals
                                                                                                                                                                                                                                                                                                          • 3234 Transmission of Random Excitations
                                                                                                                                                                                                                                                                                                            • 324 Frequency-Domain Representations
                                                                                                                                                                                                                                                                                                              • 3241 Fourier Spectrum Method
                                                                                                                                                                                                                                                                                                              • 3242 Power Spectral Density Method
                                                                                                                                                                                                                                                                                                                • 325 Response Spectrum
                                                                                                                                                                                                                                                                                                                  • 3251 Displacement Velocity and Acceleration Spectra
                                                                                                                                                                                                                                                                                                                  • 3252 Response-Spectra Plotting Paper
                                                                                                                                                                                                                                                                                                                  • 3253 Zero-Period Acceleration
                                                                                                                                                                                                                                                                                                                  • 3254 Uses of Response Spectra
                                                                                                                                                                                                                                                                                                                    • 326 Comparison of Various Representations
                                                                                                                                                                                                                                                                                                                      • 33 Pretest Procedures
                                                                                                                                                                                                                                                                                                                        • 331 Purpose of Testing
                                                                                                                                                                                                                                                                                                                        • 332 Service Functions
                                                                                                                                                                                                                                                                                                                          • 3321 Active Equipment
                                                                                                                                                                                                                                                                                                                          • 3322 Passive Equipment
                                                                                                                                                                                                                                                                                                                          • 3323 Functional Testing
                                                                                                                                                                                                                                                                                                                            • 333 Information Acquisition
                                                                                                                                                                                                                                                                                                                              • 3331 Interface Details
                                                                                                                                                                                                                                                                                                                              • 3332 Effect of Neglecting Interface Dynamics
                                                                                                                                                                                                                                                                                                                              • 3333 Effects of Damping
                                                                                                                                                                                                                                                                                                                              • 3334 Effects of Inertia
                                                                                                                                                                                                                                                                                                                              • 3335 Effect of Natural Frequency
                                                                                                                                                                                                                                                                                                                              • 3336 Effect of Excitation Frequency
                                                                                                                                                                                                                                                                                                                              • 3337 Other Effects of Interface
                                                                                                                                                                                                                                                                                                                                • 334 Test-Program Planning
                                                                                                                                                                                                                                                                                                                                  • 3341 Testing of Cabinet-Mounted Equipment
                                                                                                                                                                                                                                                                                                                                    • 335 Pretest Inspection
                                                                                                                                                                                                                                                                                                                                      • 34 Testing Procedures
                                                                                                                                                                                                                                                                                                                                        • 341 Resonance Search
                                                                                                                                                                                                                                                                                                                                        • 342 Methods of Determining Frequency-Response Functions
                                                                                                                                                                                                                                                                                                                                          • 3421 Fourier Transform Method
                                                                                                                                                                                                                                                                                                                                          • 3422 Spectral Density Method
                                                                                                                                                                                                                                                                                                                                          • 3423 Harmonic Excitation Method
                                                                                                                                                                                                                                                                                                                                            • 343 Resonance-Search Test Methods
                                                                                                                                                                                                                                                                                                                                              • 3431 Hammer (Bump) Test and Drop Test
                                                                                                                                                                                                                                                                                                                                              • 3432 Pluck Test
                                                                                                                                                                                                                                                                                                                                              • 3433 Shaker Tests
                                                                                                                                                                                                                                                                                                                                                • 344 Mechanical Aging
                                                                                                                                                                                                                                                                                                                                                  • 3441 Equivalence for Mechanical Aging
                                                                                                                                                                                                                                                                                                                                                  • 3442 Excitation-Intensity Equivalence
                                                                                                                                                                                                                                                                                                                                                  • 3443 Dynamic-Excitation Equivalence
                                                                                                                                                                                                                                                                                                                                                  • 3444 Cumulative Damage Theory
                                                                                                                                                                                                                                                                                                                                                    • 345 Test-Response Spectrum Generation
                                                                                                                                                                                                                                                                                                                                                    • 346 Instrument Calibration
                                                                                                                                                                                                                                                                                                                                                    • 347 Test-Object Mounting
                                                                                                                                                                                                                                                                                                                                                    • 348 Test-Input Considerations
                                                                                                                                                                                                                                                                                                                                                      • 3481 Test Nomenclature
                                                                                                                                                                                                                                                                                                                                                      • 3482 Testing with Uncorrelated Excitations
                                                                                                                                                                                                                                                                                                                                                      • 3483 Symmetrical Rectilinear Testing
                                                                                                                                                                                                                                                                                                                                                      • 3484 Geometry vs Dynamics
                                                                                                                                                                                                                                                                                                                                                      • 3485 Some Limitations
                                                                                                                                                                                                                                                                                                                                                      • 3486 Testing Black Boxes
                                                                                                                                                                                                                                                                                                                                                      • 3487 Phasing of Excitations
                                                                                                                                                                                                                                                                                                                                                      • 3488 Testing a Gray or White Box
                                                                                                                                                                                                                                                                                                                                                      • 3489 Overtesting in Multitest Sequences
                                                                                                                                                                                                                                                                                                                                                          • 35 Some Practical Information
                                                                                                                                                                                                                                                                                                                                                            • 351 Random Vibration Test Example
                                                                                                                                                                                                                                                                                                                                                            • 352 Vibration Shakers and Control Systems
                                                                                                                                                                                                                                                                                                                                                              • Bibliography
                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                  • 53191ch4
                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                    • Chapter 4 Experimental Modal Analysis
                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                      • 41 Introduction
                                                                                                                                                                                                                                                                                                                                                                      • 42 Frequency-Domain Formulation
                                                                                                                                                                                                                                                                                                                                                                        • 421 Transfer-Function Matrix
                                                                                                                                                                                                                                                                                                                                                                        • 422 Principle of Reciprocity
                                                                                                                                                                                                                                                                                                                                                                          • 43 Experimental Model Development
                                                                                                                                                                                                                                                                                                                                                                            • 431 Extraction of the Time-Domain Model
                                                                                                                                                                                                                                                                                                                                                                              • 44 Curve Fitting of Transfer Functions
                                                                                                                                                                                                                                                                                                                                                                                • 441 Problem Identification
                                                                                                                                                                                                                                                                                                                                                                                • 442 Single- and Multi-Degree-of-Freedom Techniques
                                                                                                                                                                                                                                                                                                                                                                                • 443 Single-Degree-of-Freedom Parameter Extraction in the Frequency Domain
                                                                                                                                                                                                                                                                                                                                                                                  • 4431 Circle-Fit Method
                                                                                                                                                                                                                                                                                                                                                                                    • Case of Viscous Damping
                                                                                                                                                                                                                                                                                                                                                                                    • Case of Hysteretic Damping
                                                                                                                                                                                                                                                                                                                                                                                      • 4432 Peak-Picking Method
                                                                                                                                                                                                                                                                                                                                                                                        • 444 Multi-Degree of Freedom Curve Fitting
                                                                                                                                                                                                                                                                                                                                                                                          • 4441 Formulation of the Method
                                                                                                                                                                                                                                                                                                                                                                                            • 445 A Comment on Static Modes and Rigid-Body Modes
                                                                                                                                                                                                                                                                                                                                                                                            • 446 Residue Extraction
                                                                                                                                                                                                                                                                                                                                                                                              • 45 Laboratory Experiments
                                                                                                                                                                                                                                                                                                                                                                                                • 451 Lumped-Parameter System
                                                                                                                                                                                                                                                                                                                                                                                                  • 4511 Frequency-Domain Test
                                                                                                                                                                                                                                                                                                                                                                                                  • 4512 Time-Domain Tests
                                                                                                                                                                                                                                                                                                                                                                                                    • 452 Distributed-Parameter System
                                                                                                                                                                                                                                                                                                                                                                                                      • 46 Commercial EMA Systems
                                                                                                                                                                                                                                                                                                                                                                                                        • 461 System Configuration
                                                                                                                                                                                                                                                                                                                                                                                                          • 4611 FFT Analysis Options
                                                                                                                                                                                                                                                                                                                                                                                                          • 4612 Modal Analysis Components
                                                                                                                                                                                                                                                                                                                                                                                                              • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                  • 53191ch5
                                                                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                    • Chapter 5 Mechanical Shock
                                                                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                      • 51 Definitions
                                                                                                                                                                                                                                                                                                                                                                                                                        • 511 Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 512 Simple (or Perfect) Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 513 Half-Sine Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 514 Versed-Sine (or Haversine) Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 515 Terminal Peak Sawtooth Shock or Final Peak Sawtooth Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 516 Rectangular Shock
                                                                                                                                                                                                                                                                                                                                                                                                                          • 5161 Trapezoidal Shock
                                                                                                                                                                                                                                                                                                                                                                                                                              • 52 Description in the Time Domain
                                                                                                                                                                                                                                                                                                                                                                                                                              • 53 Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                • 531 Need
                                                                                                                                                                                                                                                                                                                                                                                                                                • 532 Shock Response Spectrum Definition
                                                                                                                                                                                                                                                                                                                                                                                                                                • 533 Response of a Linear One-Degree-of-Freedom System
                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5331 Shock Defined by a Force
                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5332 Shock Defined by an Acceleration
                                                                                                                                                                                                                                                                                                                                                                                                                                    • 534 Definitions
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5341 Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5342 Absolute Acceleration Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5343 Relative Displacement Shock Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5344 Primary Positive Shock Response Spectrum or Initial Positive Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5345 Primary (or Initial) Negative Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5346 Secondary (or Residual) Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5347 Positive (or Maximum Positive) Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5348 Negative (or Maximum Negative) Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5349 Maximax Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53410 Choice of Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                        • 535 Standardized Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5351 Definition
                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5352 Standardized Shock Response Spectra of Simple Shocks
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53521 Half-Sine Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53522 Versed Sine Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53523 Terminal Peak Sawtooth Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53524 Rectangular Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53525 Trapezoidal Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 536 Choice of Damping
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 537 Shock Response Spectra Domains
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 538 Algorithms for Calculation of the Shock Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 539 Choice of the Digitization Frequency of the Signal
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5310 Use of Shock Response Spectra for the Study of Systems with Several Degrees of Freedom
                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 54 Pyroshocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 55 Use of Shock Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 551 Severity Comparison of Several Shocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 552 Test Specification Development from Real Environment Data
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5521 Synthesis of Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5522 Nature of the Specification
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5523 Choice of Shape
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5524 Amplitude
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5525 Duration
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5526 Difficulties
                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 56 Standards
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 561 Types of Standards
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 562 Installation Conditions of Test Item
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 563 Uncertainty Factor
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 564 Bump Test
                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 57 Damage Boundary Curve
                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 571 Definition
                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 572 Analysis of Test Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 58 Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 581 Main Types
                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 582 Impact Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5821 Universal Shock-Test Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 58211 Impact Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 58212 Impulse Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 583 Shock Simulators (Programmers)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5831 Half-Sine Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58311 Shock Duration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58312 Impact Velocity
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58313 Maximum Deformation of the Shock Simulator (Programmer)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58314 Shock Amplitude
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58315 Characteristics of the Target
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5832 Terminal Peak Sawtooth Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5833 Rectangular Pulse ndash Trapezoidal Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5834 Universal Shock Simulator (Programmer)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 58341 Generating a Half-Sine Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 58342 Generating a Terminal Peak Sawtooth Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 58343 Trapezoidal Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 584 Limitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5841 Limitations of the Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5842 Limitations of Shock Simulators
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 585 Pneumatic Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 586 High Impact Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5861 Lightweight High Impact Shock Machine
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5862 Medium Weight High Impact Shock Machine
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 587 Specific Test Facilities
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 59 Generation of Shock Using Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 591 Principle Behind the Generation of a Simple Shape Signal versus Time
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 592 Main Advantages
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 593 Pre- and Postshocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5931 Requirements
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5932 Solutions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 59321 Optimized Pre- and Postpulses
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5933 Incidence on the Shock Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 594 Limitations of Electrodynamic Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5941 Mechanical Limitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 59411 Abacuses
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5942 Electronic Limitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 595 The Use of Electrohydraulic Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 510 Control by a Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 5101 Principle
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 5102 Principal Shapes of Elementary Signals
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 51021 Decaying Sinusoid
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 51022 ZERD Function
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 51023 WAVSIN Waveform
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 5103 Comparison of WAVSIN SHOC Waveforms and Decaying Sinusoid
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 5104 Criticism of Control by a Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 511 Pyrotechnic Shock Simulation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5111 Simulation Using Pyrotechnic Facilities
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5112 Simulation Using Metal-to-Metal Impact
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5113 Simulation Using Electrodynamic Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5114 Simulation Using Conventional Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53191ch6
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Chapter 6 Machine Condition Monitoring and Fault Diagnostics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 61 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 62 Machinery Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 621 Causes of Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 622 Types of Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 623 Frequency of Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 63 Basic Maintenance Strategies
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 631 Run-to-Failure (Breakdown) Maintenance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 632 Scheduled (Preventative) Maintenance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 633 Condition-Based (Predictive Proactive Reliability Centered On-Condition) Maintenance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 64 Factors Which Influence Maintenance Strategy
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 65 Machine Condition Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 651 Periodic Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 652 Continuous Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 66 Transducer Selection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 661 Noncontact Displacement Transducers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 662 Velocity Transducers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 663 Acceleration Transducers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 67 Transducer Location
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 68 Recording and Analysis Instrumentation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 681 Vibration Meters
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 682 Data Collectors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 683 Frequency-Domain Analyzers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 684 Time-Domain Instruments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 685 Tracking Analyzers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 69 Display Formats and Analysis Tools
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 691 Time Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6911 Time-Waveform Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6912 Time-Waveform Indices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6913 Time-Synchronous Averaging
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6914 Negative Averaging
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6915 Orbits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6916 Probability Density Functions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6917 Probability Density Moments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 692 Frequency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6921 Band-Pass Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6922 Shock Pulse (Spike Energy)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6923 Enveloped Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6924 Signature Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6925 Cascades (Waterfall Plots)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6926 Masks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6927 Frequency-Domain Indices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 693 Modal Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 694 Quefrency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 610 Fault Detection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 6101 Standards
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61011 Standards Based on Machinery Type
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61012 Standards Based on Vibration Severity
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 6102 Acceptance Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 61021 Statistical Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 6103 Frequency-Domain Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61031 Limited Band Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61032 Constant Bandwidth Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61033 Constant Percentage Bandwidth Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 611 Fault Diagnostics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 6111 Forcing Functions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61111 Unbalance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61112 Misalignment
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61113 Mechanical Looseness
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61114 Soft Foot
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61115 Rubs
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61116 Resonances
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61117 Oil Whirl
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61118 Oil Whip
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61119 Structural Vibrations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 611110 Foundation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 6112 Specific Machine Components
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 61121 Damaged or Worn Rolling-Element Bearings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 61122 Damaged or Worn Gears
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 6113 Specific Machine Types
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61131 Pumps
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61132 Fans
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61133 Electric Motors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61134 Steam and Gas Turbines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61135 Compressors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61136 Reciprocating Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 6114 Advanced Fault Diagnostic Techniques
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 53191ch7
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • Chapter 7 Vibration-Based Tool Condition Monitoring Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 71 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 72 Mechanics of Turning
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 721 General Terms
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 722 Chatter Vibrations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 723 Tool Wear
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7231 Tool Failure Mechanisms
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7232 Tool Failure Modes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7233 Tool Wear Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7234 Tool Wear Stages
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 73 Vibration Signal Recording
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 731 Direct and Indirect Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 732 Sensor Requirements for Tool Wear Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 733 Force Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7331 Direct Measurement Dynamometers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7332 Indirect Force Sensors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7333 Piezoelectric Strain Sensors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7334 Resistance Strain Gauges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7335 Customized Force Sensors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 734 Acceleration Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 735 Acoustic Emission Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 736 Sensor Comparisons
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 74 Signal Processing for Sensor-Based Tool Condition Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 741 Feature Extraction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7411 Time Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7412 Frequency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7413 Statistical Processing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7414 TimendashFrequency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 742 Feature Selection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 75 Wear ModelDecision-Making for Sensor-Based Tool Condition Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 751 Trending Threshold
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 752 Neural Networks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7521 Unsupervised Networks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7522 Supervised Networks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 753 Fuzzy Logic
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 754 Other Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 76 Conclusion
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53191ch8
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Chapter 8 Fault Diagnosis of Helicopter Gearboxes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 81 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 82 Abnormality Scaling
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 83 The Structure-Based Connectionist Network
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 84 Sensor Location Selection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 841 Coverage Index
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 842 Overlap Index
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 843 Monitoring Effectiveness
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 85 A Case Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 851 Structural and Featural Influences
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 852 Evaluation of Influences
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 853 Fault Detection Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 854 Fault Diagnostic Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 8541 Faulty Subsystem Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 8542 Faulty Component Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 855 Sensor Location Evaluation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 856 Sensor Location Validation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 86 Conclusion
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 53191ch9
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Chapter 9 Vibration Suppression and Monitoring in Precision Motion Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 91 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 92 Mechanical Design to Minimize Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 921 Stability and Static Determinacy of Machine Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 922 Two-Dimensional Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 923 Three-Dimensional Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 93 Adaptive Notch Filter
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 931 Fast Fourier Transform
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 932 Simulation and Experiments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 94 Real-Time Vibration Analyzer
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 941 Learning Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 942 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 943 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 944 Experiments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 9441 Input Variables mdash the Evaluation Criteria
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 94411 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 94412 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 9442 Evaluation Rules
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 94421 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 94422 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 9443 Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 94431 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 94432 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 95 Practical Insights and Case Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 96 Conclusions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 53191ch10
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Chapter 10 Vibration and Shock Problems of Civil Engineering Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 101 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 102 Earthquake-Induced Vibration of Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1021 Seismicity and Ground Motions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1022 Influence of Local Site Conditions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1023 Response of Structures to Ground Motions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1024 Dynamic Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10241 Equations of Motion for Linear Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10242 Equations of Motion for Linear Multiple-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1025 Earthquake Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10251 Elastic Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10252 Smoothed Design Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10253 Ductility-Modified Response Spectrum Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1026 Design Philosophy and the Code Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10261 Performance-Based Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1027 Analysis Options for Earthquake Effects
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10271 Dynamic Time History Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10272 Response Spectrum Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 102721 Response Spectrum Analysis of Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 102722 Response Spectrum Analysis of Multi-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10273 Equivalent Static Analysis (Force-Based Approach)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10274 Displacement-Based Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1028 SoilndashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1029 Active and Passive Control Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 10210 Worked Examples
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 103 Dynamic Effects of Wind Loading on Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1031 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1032 Wind Speed
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1033 Design Structures for Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10331 Types of Wind Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10332 Design Criteria
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10333 Static Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1034 Along and Across-Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10341 Along-Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10342 Across-Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1035 Wind Tunnel Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1036 Comfort Criteria Human Response to Building Motion
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1037 Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1038 Comparison with Earthquake Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 104 Vibrations Due to Fluid ndashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1041 Added Mass and Inertial Coupling
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1042 Wave-Induced Vibration of Structure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 105 Blast Loading and Blast Effects on Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1051 Explosions and Blast Phenomenon
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1052 Explosive Air-Blast Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10521 Blast Wave Scaling Laws
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10522 Prediction of Blast Pressure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1053 Gas Explosion Loading and Effect of Internal Explosions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1054 Structural Response to Blast Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10541 Elastic Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10542 Elasto-Plastic Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1055 Material Behaviors at High Strain Rate
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10551 Dynamic Properties of Concrete under High Strain Rates
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10552 Dynamic Properties of Reinforcing Steel under High Strain Rates
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1056 Failure Modes of Blast-Loaded Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10561 Global Structural Behavior
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10562 Localized Structural Behavior
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10563 PressurendashImpulse ( PndashI ) Diagrams
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1057 Blast WavendashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1058 Effect of Ground Shocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10581 Loads from Air-Induced Ground Shock
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10582 Loads from Direct Ground Shock
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1059 Technical Design Manuals for Blast-Resistant Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 10510 Computer Programs for Blast and Shock Effects
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 106 Impact Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1061 Structural Impact between Two Bodies mdash Hard Impact and Soft Impact
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1062 Example mdash Aircraft Impact
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 107 Floor Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1071 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1072 Types of Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10721 Walking
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10722 Rhythmic Activities
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10723 Mechanical Equipment
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10724 Analysis Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1073 Natural Frequency of Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10731 Computing the Natural Frequency
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10732 Computing Deflection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10733 Damping
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10734 Resonance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1074 Vibration Caused by Walking
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10741 Minimum Natural Frequency
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1075 Design for Rhythmic Excitation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10751 Harmonics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10752 Minimum Natural Frequency
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1076 Example mdash Vibration Analysis of a Reinforced Concrete Floor
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 53191ch11
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Chapter 11 Seismic Base Isolation and Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 111 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1111 From Ductility Design to Base Isolation and Control Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1112 The Importance of Reducing Seismic Input and Response
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 112 Seismic Base Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1121 Historical Development of Base Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1122 Basic Principle
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1123 Issues in Seismic Base Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11231 Performance Criteria
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11232 Type of Structure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11233 Site Characteristics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11234 Retrofit Issues
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11235 Design of Building Services
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11236 Expected Life of Isolator
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1124 Seismic Isolation Devices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11241 Laminated Rubber Bearings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11242 Lead Rubber Bearing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11243 Friction-Based Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11244 Other Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1125 Design of Isolation Devices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11251 High-Damping Rubber Bearing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112511 Stability against Buckling
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112512 Stability against Roll Out
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11252 Lead Rubber Bearings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112521 Design of Lead Plug
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112522 Design of Laminated Rubber Bearing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11253 Design of Friction Pendulum System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1126 Verification of Properties of Isolation Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11261 Tests for Isolation Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 112611 System Characterization Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 112612 Prototype Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 112613 Quality Control Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11262 Uniform Building Code Recommendations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112621 Units Dependent on Loading Rates
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112622 Units Dependent on Bilateral Load
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112623 System Adequacy
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1127 Analysis of Base-Isolated Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11271 Modeling of a Superstructure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11272 Modeling of Isolation System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11273 Static Analysis Procedure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11274 Dynamic Analysis Procedure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 112741 Response Spectrum Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 112742 Time-History Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11275 Software for Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1128 Experimental Methods for Isolated Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1129 Implementation of Seismic Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11291 New Construction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112911 Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112912 Bridges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11292 Seismic Retrofit
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112921 Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112922 Bridges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11293 Other Implementations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 11210 Performance during Past Earthquakes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 112101 Performance of Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 112102 Performance of Bridges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 113 Seismic Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1131 Historical Development of Seismic Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1132 Basic Principles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11321 Passive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11322 Active Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11323 Semiactive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11324 Hybrid Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11325 Categorization of Basic Principles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1133 Important Issues in Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11331 SoilndashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11332 DevicendashStructure Interaction and Time Delay
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11333 Design Guidelines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1134 Vibration-Control Devices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11341 Passive Control Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113411 Metallic Yielding Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113412 Friction Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113413 Viscoelastic Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113414 Viscous Fluid Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113415 Tuned Mass Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11342 Active Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113421 Electromagnetic Actuator
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113422 Hydraulic Actuators
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11343 Semiactive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113431 Variable-Orifice Hydraulic Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113432 Controllable Fluid Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113433 Controllable Friction Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11344 Hybrid Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1135 Control Algorithm
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11351 Active Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11352 Semiactive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113521 Common Control Schemes for Controllable Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113522 Special Control Schemes for Controllable Damper
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1136 Experimental Performance Verification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11361 Shaking Table Tests of a Flexible Structural Model with TMD AMD and ATMD
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11362 Substructure Hybrid Test
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113621 Hybrid Tests Using Hydraulic Actuator
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113622 Hybrid Tests Using Shaking Table
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113623 Hybrid Tests Using Inertia-Force-Driven Loading System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1137 Implementations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11371 Semiactive Control of Full-Scale Structures Using Variable Joint Damper System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113711 Background of Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113712 Test System Set Up
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113713 Control Algorithm
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113714 Test Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11372 Application of Structural Control Technologies to Seismic Retrofit of a Cable-Stayed Bridge
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113721 Background of Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113722 Basic Concept of Seismic Retrofit
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113723 Modal Shape Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113724 Time-History Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113725 Soil ndash Structure Interaction Effect
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113726 Semiactive Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53191ch12
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Chapter 12 Seismic Random Vibration of Long-Span Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 121 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1211 Basic Concepts of Random Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12111 Stationary Random Process
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12112 Nonstationary Random Process
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1212 Three Methods for Structural Seismic Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12121 Response Spectrum Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12122 Time-History Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12123 Random Vibration Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 121231 Davenport Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 121232 Vanmarcke Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 12124 Comparisons of the Three Seismic-Analysis Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 122 Seismic Random-Excitation Fields
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1221 Power Spectral Density of Spatially Varying Ground Acceleration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1222 Several Coherence Models
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12221 FengndashHu Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12222 Harichandran ndashVanmarcke Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12223 LohndashYeh Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12224 OliveirandashHaondashPenzien Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12225 LucondashWong Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12226 QundashWangndashWang Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1223 Generation of Ground Acceleration Power Spectral Density Curves from Acceleration Response Spectrum Curves
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12231 Kaul Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12232 Iteration Scheme
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1224 Seismic Equations of Motion of Long-Span Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1225 Seismic Waves and Their Geometrical Expressions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 123 Pseudoexcitation Method for Structural Random Vibration Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1231 Structures Subjected to Stationary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12311 Single Stationary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12312 Multiple Stationary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1232 Structures Subjected to Nonstationary Random Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12321 Structures Subjected to Uniformly Modulated Evolutionary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 123211 Single Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 123212 Multiple Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12322 Structures Subjected to Nonuniformly Modulated Evolutionary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 123221 Single Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 123222 Multiple Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1233 Precise Integration Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12331 Precise Integration of Exponential Matrices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12332 Particular Solutions and Precise Integration Formulas for Various Forms of Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 123321 Linear Loading Form (HPD-L Form)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 123322 Sinusoidal Loading Form (HPD-S Form)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 123323 Exponentially Decaying Sinusoidal Loading Form (HPD-E Form)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 124 Long-Span Structures Subjected to Stationary Random Ground Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1241 The Solution of Equations of Motion Using the Pseudoexcitation Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1242 Numerical Comparisons with Other Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12421 Song-Hua-Jiang Suspension Bridge
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 124211 All Supports Move Uniformly
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 124212 Wave Passage Effect Is Taken into Account
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 124213 Wave-Passage Effect and Incoherence Effect Are Jointly Taken into Account
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 12422 San Joaquin Concrete Bridge
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 125 Long-Span Structures Subjected to Nonstationary Random Ground Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1251 Modulation Functions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1252 The Formulas for Nonstationary Multiexcitation Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1253 Expected Extreme Values of Nonstationary Random Processes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1254 Numerical Comparisons with the Corresponding Stationary Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 126 Conclusions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Related Titles
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                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Chapter 13 Seismic Qualification of Equipment
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 131 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 132 Distribution Qualification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1321 Drive-Signal Generation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1322 Distribution Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1323 Test Procedures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 133 Seismic Qualification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1331 Stages of Seismic Qualification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1332 Test Preliminaries
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1333 Single-Frequency Testing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1334 Multifrequency Testing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1335 Generation of RRS Specifications
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Bibliography
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                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Chapter 14 Human Response to Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 141 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 142 Vibration Excitations on Humans
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1421 Excitation Characteristics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 143 Human Response to Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1431 Vibration Perception
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1432 Frequency Weighting Curve
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1433 Iso-Perception Curves
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1434 Detection Threshold Curve
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 144 Regulation of Human Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1441 Acceptable Vibration Levels in Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1442 Whole-Body Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1443 HandndashArm Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Bibliography
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Page 13: Vibration Monitoring, Testing, and Instrumentationpreview.kingborn.net › 646000 › d1a74678d91943e5ba1d5e... · The MEMS Handbook, Second Edition MEMS: Introduction and Fundamentals

1Vibration

Instrumentation

Clarence W de SilvaThe University of British Columbia

11 Introduction 1-1

12 Vibration Exciters 1-3Shaker Selection dagger Dynamics of Electromagnetic Shakers

13 Control System 1-15Components of a Shaker Controller dagger Signal-Generating

Equipment

14 Performance Specification 1-21Parameters for Performance Specification dagger Linearity dagger

Instrument Ratings dagger Accuracy and Precision

15 Motion Sensors and Transducers 1-27Potentiometer dagger Variable-Inductance Transducers dagger

Mutual-Induction Proximity Sensor dagger Selfinduction

Transducers dagger Permanent-Magnet Transducers dagger

Alternating Current Permanent-Magnet Tachometer dagger

Alternating Current Induction Tachometer dagger Eddy Current

Transducers dagger Variable-Capacitance Transducers dagger

Piezoelectric Transducers

16 Torque Force and Other Sensors 1-50Strain Gage Sensors dagger Miscellaneous Sensors

Appendix 1A Virtual Instrumentation for DataAcquisition Analysis and Presentation 1-73

Summary

Devices useful in instrumenting a mechanical vibrating system are presented in this chapter Shakers whichgenerate vibration excitations are discussed and compared A variety of sensors including motion sensorsproximity sensors forcetorque sensors and other miscellaneous sensors are considered Performance specificationin the time domain and the frequency domain is addressed Rating parameters of instruments are given

11 Introduction

Measurement and associated experimental techniques play a significant role in the practice of vibration

Academic exposure to vibration instrumentation usually arises in laboratories in the context of learning

training and research In vibration practice perhaps the most important task of instrumentation is the

measurement or sensing of vibration Vibration sensing is useful in the following applications

1 Design and development of a product

2 Testing (screening) of a finished product for quality assurance

3 Qualification of a good-quality product to determine its suitability for a specific application

1-1

53191mdash522007mdash1201mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

4 Mechanical aging of a product prior to carrying out a test program

5 Exploratory testing of a product to determine its dynamic characteristics such as resonances

mode shapes and even a complete dynamic model

6 Vibration monitoring for performance evaluation

7 Control and suppression of vibration

Figure 11 indicates a procedure typical of experimental vibration highlighting the essential

instrumentation Vibrations are generated in a device the test object in response to some excitation In

some experimental procedures primarily in vibration testing (see Figure 11) the excitation signal has

to be generated in a signal generator in accordance with some requirement (specification) and applied to

the object through an exciter after amplification and conditioning In some other situations primarily in

performance monitoring and vibration control the excitations are generated as an integral part of the

operating environment of the vibrating object and may originate either within the object (eg engine

excitations in an automobile) or in the environment with which the object interacts during operation

(eg road disturbances on an automobile) Sensors are needed to measure vibrations in the test object In

particular a control sensor is used to check whether the specified excitation is applied to the object

and one or more response sensors may be used to measure the resulting vibrations at key locations of

the object

The sensor signals have to be properly conditioned for example by filtering and amplification and

modified for example through modulation demodulation and analog-to-digital conversion prior to

recording analyzing and display The purpose of the controller is to guarantee that the excitation is

correctly applied to the test object If the signal from the control sensor deviates from the required

excitation the controller modifies the signal to the exciter so as to reduce this deviation Furthermore the

controller will stabilize or limit (compress) the vibrations in the object It follows that instruments in

experimental vibration may be generally classified into the following categories

1 Signal-generating devices

2 Vibration exciters

3 Sensors and transducers

4 Signal conditioningmodifying devices

5 Signal analysis devices

6 Control devices

7 Vibration recording and display devices

AnalogDigital

Interface

DigitalSignal

RecorderAnalyzerDisplay

FilterAmplifier

FilterAmplifier

SignalGenerator

and ExciterController

Reference (Required)Signal (Specification)

PowerAmplifier

MountingFixtures

TestObject

ResponseSensor

ControlSensor

Exciter

SwivelBase

FIGURE 11 Typical instrumentation in experimental vibration

Vibration Monitoring Testing and Instrumentation1-2

53191mdash522007mdash1201mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

Note that one instrument may perform the tasks

of more than one category listed here Also more

than one instrument may be needed to carry out

tasks in a single category In the following sections

we will provide some examples of the types of

vibration instrumentation giving characteristics

operating principles and important practical

considerations Also we will describe several

experiments which can be found in a typical

vibration laboratory

An experimental vibration system generally

consists of four main subsystems

1 Test object

2 Excitation system

3 Control system

4 Signal acquisition and modification system

These are schematically shown in Figure 12 Note that various components shown in Figure 11 may

be incorporated into one of these subsystems In particular component matching hardware and object

mounting fixtures may be considered interfacing devices that are introduced through the interaction

between the main subsystems as shown in Figure 12 Some important issues of vibration testing and

instrumentation are summarized in Box 11

12 Vibration Exciters

Vibration experimentation may require an external exciter to generate the necessary vibration This is the

case in controlled experiments such as product testing where a specified level of vibration is applied to the

test object and the resulting response is monitored A variety of vibration exciters are available with

different capabilities and principles of operation

Three basic types of vibration exciters (shakers) are widely used hydraulic shakers inertial shakers

and electromagnetic shakers The operation-capability ranges of typical exciters in these three categories

are summarized in Table 11 Stroke or maximum displacement is the largest displacement the exciter

is capable of imparting onto a test object whose weight is assumed to be within its design load limit

Maximum velocity and acceleration are similarly defined Maximum force is the largest force that could

be applied by the shaker to a test object of acceptable weight (one within the design load) The values

given in Table 11 should be interpreted with caution Maximum displacement is achieved only at very

low frequencies The achievement of maximum velocity corresponds to intermediate frequencies in the

operating frequency range of the shaker Maximum acceleration and force ratings are usually achieved at

high frequencies It is not feasible for example to operate a vibration exciter at its maximum

displacement and its maximum acceleration simultaneously

Consider a loaded exciter that is executing harmonic motion Its displacement is given by

x frac14 s sin vt eth11THORN

in which s is the displacement amplitude (or stroke) Corresponding velocity and acceleration are

_x frac14 sv cos vt eth12THORN

eurox frac14 2sv2sin vt eth13THORN

SignalModification

System

TestObject

ControlSystem

VibrationExciter (Shaker)

System

FIGURE 12 Interactions between major subsystems of

an experimental vibration system

Vibration Instrumentation 1-3

53191mdash522007mdash1201mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

If the velocity amplitude is denoted by v and the acceleration amplitude by a it follows from Equation

12 and Equation 13 thatv frac14 vs eth14THORN

and

a frac14 vv eth15THORN

Box 11

VIBRATION INSTRUMENTATION

Vibration Testing Applications for Products

Design and Development Production Screening and Quality Assessment Utilization and Qualification for Special Applications

Testing Instrumentation

Exciter (excites the test object) Controller (controls the exciter for accurate excitation) Sensors and Transducers (measure excitations and responses and provide excitation error

signals to controller) Signal Conditioning (converts signals to appropriate form) Recording and Display (perform processing storage and documentation)

Exciters

Shakers

1 Electrodynamic (high bandwidth moderate power complex and multifrequency

excitations)

2 Hydraulic (moderate to high bandwidth high power complex and multifrequency

excitations)

3 Inertial (low bandwidth low power single-frequency harmonic excitations)

TransientInitial Condition

1 Hammers (impulsive bump tests)

2 Cable Release (step excitations)

3 Drop (impulsive)

Signal Conditioning

Filters Amplifiers Amplifiers ModulatorsDemodulators ADCDAC

Sensors

Motion (displacement velocity acceleration) Force (strain torque)

Vibration Monitoring Testing and Instrumentation1-4

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copy 2007 by Taylor amp Francis Group LLC

TABLE 11 Typical Operation-Capability Ranges for Various Shaker Types

Shaker Type Typical Operational Capabilities

Frequency Maximum Displacement

(Stroke)

Maximum

Velocity

Maximum

Acceleration

Maximum

Force

Excitation

Waveform

Hydraulic

(electrohydraulic)

Low

(01ndash500 Hz)

High (20 in 50 cm) Intermediate

(50 insec

125 cmsec)

Intermediate

(20 g)

High (100000 lbf

450000 N)

Average flexibility (simple

to complex and random)

Inertial

(counter-rotating mass)

Intermediate

(2ndash50 Hz)

Low (1 in 25 cm) Intermediate

(50 insec

125 cmsec)

Intermediate

(20 g)

Intermediate

(1000 lbf 4500 N)

Sinusoidal only

Electromagnetic

(electrodynamic)

High

(2ndash10000 Hz)

Low (1 in 25 cm) Intermediate

(50 insec

125 cmsec)

High (100 g) Low to intermediate

(450 lbf 2000 N)

High flexibility and accuracy

(simple to complex and

random)

VibrationInstru

mentation

1-5

53191mdash522007mdash

1201mdashSENTHILKUMARmdash246494mdash

CRCndashpp1ndash112

copy 2007 by Taylor amp Francis Group LLC

An idealized performance curve of a shaker

has a constant displacementndashamplitude region a

constant velocityndashamplitude region and a con-

stant accelerationndashamplitude region for low

intermediate and high frequencies respectively

in the operating frequency range Such an ideal

performance curve is shown in Figure 13(a) on a

frequencyndashvelocity plane Logarithmic axes are

used In practice typical shaker performance

curves would be fairly smooth yet nonlinear

curves similar to those shown in Figure 13(b)

As the mass increases the performance curve

compresses Note that the acceleration limit of a

shaker depends on the mass of the test object

(load) Full load corresponds to the heaviest object

that could be tested The ldquono loadrdquo condition

corresponds to a shaker without a test object To

standardize the performance curves they are

usually defined at the rated load of the shaker A

performance curve in the frequencyndashvelocity

plane may be converted to a curve in the

frequencyndashacceleration plane simply by increasing

the slope of the curve by a unit magnitude (ie

20 dbdecade)

Several general observations can be made from

Equation 14 and Equation 15 In the constant-

peak displacement region of the performance

curve the peak velocity increases proportionally

with the excitation frequency and the peak

acceleration increases with the square of the excitation frequency In the constant-peak velocity region

the peak displacement varies inversely with the excitation frequency and the peak acceleration increases

proportionately In the constant-peak acceleration region the peak displacement varies inversely with the

square of the excitation frequency and the peak velocity varies inversely with the excitation frequency

This further explains why rated stroke maximum velocity and maximum acceleration values are not

simultaneously realized

121 Shaker Selection

Vibration testing is accomplished by applying a specified excitation to the test package using a shaker

apparatus and monitoring the response of the test object Test excitation may be represented by its

response spectrum The test requires that the response spectrum of the actual excitation known as the

test response spectrum (TRS) envelops the response spectrum specified for the particular test known as

the required response spectrum (RRS)

A major step in the planning of any vibration testing program is the selection of a proper shaker

(exciter) system for a given test package The three specifications that are of primary importance in

selecting a shaker are the force rating the power rating and the stroke (maximum displacement) rating

Force and power ratings are particularly useful in moderate to high frequency excitations and the stroke

rating is the determining factor for low frequency excitations In this section a procedure is given to

determine conservative estimates for these parameters in a specified test for a given test package

Frequency domain considerations are used here

Stroke

Limit M

ax

Acceleration

MaxVelocity

Peak

Vel

ocity

(cm

s)

01 1 10 100

FullLoad

NoLoad

Frequency (Hz)(a)

Peak

Vel

ocity

(cm

s)

100

10

1

100

10

1

01 1 10 100

FullLoad

NoLoad

Frequency (Hz)(b)

FIGURE 13 Performance curve of a vibration exciter

in the frequencyndashvelocity plane (log) (a) ideal (b)

typical

Vibration Monitoring Testing and Instrumentation1-6

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copy 2007 by Taylor amp Francis Group LLC

1211 Force Rating

In the frequency domain the (complex) force at the exciter (shaker) head is given by

F frac14 mHethvTHORNasethvTHORN eth16THORNin which v is the excitation frequency variable m is the total mass of the test package including

mounting fixture and attachments asethvTHORN is the Fourier spectrum of the support-location (exciter head)

acceleration and H(v) is frequency response function that takes into account the flexibility and

damping effects (dynamics) of the test package apart from its inertia In the simplified case where the

test package can be represented by a simple oscillator of natural frequency vn and damping ratio by zt

this function becomes

HethvTHORN frac14 1thorn 2jztv=vn=12 ethv=vnTHORN2 thorn 2jztv=vn eth17THORNin which j frac14 ffiffiffiffi

21p

This approximation is adequate for most practical purposes The static weight of the

test object is not included in Equation 16 Most heavy-duty shakers which are typically hydraulic

have static load support systems such as pneumatic cushion arrangements that can exactly balance the

dead load The exciter provides only the dynamic force In cases where shaker directly supports the

gravity load in the vertical test configuration Equation 16 should be modified by adding a term to

represent this weight

A common practice in vibration test applications is to specify the excitation signal by its response

spectrum This is simply the peak response of a simple oscillator expressed as a function of its natural

frequency when its support location is excited by the specified signal Clearly the damping of the simple

oscillator is an added parameter in a response spectrum specification Typical damping ratios ethzrTHORN used inresponse spectra specifications are less than 01 (or 10) It follows that an approximate relationship

between the Fourier spectrum of the support acceleration and its response spectrum is

as frac14 2jzrarethvTHORN eth18THORNThe magnitude larethvTHORNl is the response spectrumEquation 18 substituted into Equation 16 gives

F frac14 mHethvTHORN2jzrarethvTHORN eth19THORNIn view of Equation 17 for test packages having low damping the peak value of H(v) is

approximately 1=eth2jztTHORN this should be used in computing the force rating if the test package has a

resonance within the frequency range of testing On the other hand if the test package is assumed to be

rigid then HethvTHORN oslash 1 A conservative estimate for the force rating is

Fmax frac14 methzr=ztTHORNlarethvTHORNlmax eth110THORNIt should be noted that larethvTHORNlmax is the peak value of the specified (required) response spectrum (RRS)

for acceleration

1212 Power Rating

The exciter head does not develop its maximum force when driven at maximum velocity Output power

is determined by using

p frac14 Refrac12FvsethvTHORN eth111THORNin which vsethvTHORN is the Fourier spectrum of the exciter velocity and Re [ ] denotes the real part of a complex

function Note that as frac14 jvvs Substituting Equation 16 and Equation 18 into Equation 111 gives

p frac14 eth4mz2r =vTHORNRefrac12jHethvTHORNa2r ethvTHORN eth112THORNIt follows that a conservative estimate for the power rating is

pmax frac14 2methz2r =ztTHORNfrac12larethvTHORNl2=v max eth113THORN

Vibration Instrumentation 1-7

53191mdash522007mdash1201mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

Representative segments of typical acceleration RRS curves have slope n as given by

a frac14 k1vn eth114THORN

It should be clear from Equation 113 that the maximum output power is given by

pmax frac14 k2v2n21 eth115THORN

This is an increasing function for n 1=2 and a decreasing function for n 1=2 It follows that the power

rating corresponds to the highest point of contact between the acceleration RRS curve and a line of slope

equal to 12 A similar relationship may be derived if velocity RRS curves (having slopes n2 1) are used

1213 Stroke Rating

From Equation 18 it should be clear that the Fourier spectrum xs of the exciter displacement time

history can be expressed as

xs frac14 2zrarethvTHORN=jv2 eth116THORNAn estimate for stroke rating is

xmax frac14 2zrfrac12larethvTHORNl=v2 max eth117THORNThis is of the form

xmax frac14 kvn22 eth118THORNIt follows that the stroke rating corresponds to the highest point of contact between the acceleration

RRS curve and a line of slope equal to two

Example 11

A test package of overall mass 100 kg is to be

subjected to dynamic excitation represented by the

acceleration RRS (at 5 damping) as shown in

Figure 14 The estimated damping of the test

package is 7 The test package is known to have a

resonance within the frequency range of the

specified test Determine the exciter specifications

for the test

Solution

From the development presented in the previous

section it is clear that the point F (or P) in

Figure 14 corresponds to the force and output

power ratings and the point S corresponds to

the stroke rating The co-ordinates of these

critical points are F P frac14 eth42 Hz 40 gTHORN and S frac14 eth08 Hz 075 gTHORN Equation 110 gives the force

rating as

Fmax frac14 100 pound eth005=007THORN pound 40 pound 981 N frac14 2803 N

Equation 113 gives the power rating as

pmax frac14 2 pound 100 pound eth0052=007THORN pound frac12eth40 pound 981THORN2=42 pound 2p watts frac14 417 W

Equation 117 gives the stroke rating as

xmax frac14 2 pound 005 pound frac12eth075 pound 98THORN=eth08 pound 2pTHORN2 m frac14 3 cm

Acc

eler

atio

n(g

)

Con

stan

t Dis

plac

emen

t

Constant Velo

city

Frequency (Hz)

S

FP

0101

10 10 100

10

10

FIGURE 14 Test excitation specified by an accelera-

tion RRS (5 damping)

Vibration Monitoring Testing and Instrumentation1-8

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copy 2007 by Taylor amp Francis Group LLC

1214 Hydraulic Shakers

A typical hydraulic shaker consists of a piston-cylinder arrangement (also called a ram) a servo-valve a

fluid pump and a driving electric motor Hydraulic fluid (oil) is pressurized (typical operating pressure

4000 psi) and pumped into the cylinder through a servo-valve by means of a pump that is driven by an

electric motor (typical power 150 hp) The flow (typical rate 100 galmin) that enters the cylinder is

controlled (modulated) by the servo-valve which in effect controls the resulting piston (ram) motion

A typical servo-valve consists of a two-stage spool valve which provides a pressure difference and a

controlled (modulated) flow to the piston which sets it in motion

The servo-valve itself is moved by means of a linear torque motor which is driven by the excitation-

input signal (electrical) A primary function of the servo-valve is to provide a stabilizing feedback to the

ram In this respect the servo-valve complements the main control system of the test setup The ram is

coupled to the shaker table by means of a link with some flexibility The cylinder frame is mounted on the

support foundation with swivel joints This allows for some angular and lateral misalignment which

might be caused primarily by test-object dynamics as the table moves

Two-degree-of-freedom (Two-DoF) testing requires two independent sets of actuators and three-DoF

testing requires three independent actuator sets Each independent actuator set can consist of several

actuators operated in parallel using the same pump and the same excitation-input signal to the torque

motors

If the test table is directly supported on the vertical actuators they must withstand the total dead

weight (ie the weight of the test table the test object the mounting fixtures and the instrumentation)

This is requirement is usually prevented by providing a pressurized air cushion in the gap between the

test table and the foundation walls Air should be pressurized so as to balance the total dead weight

exactly (typical required gage pressure 3 psi)

Figure 15(a) shows the basic components of a typical hydraulic shaker The corresponding

operational block diagram is shown in Figure 15(b) It is desirable to locate the actuators in a pit in the

test laboratory so that the test tabletop is flushed with the test laboratory floor under no-load conditions

This minimizes the effort required to place the test object on the test table Otherwise the test object has

to be lifted onto the test table with a forklift Also installation of an aircushion to support the system

dead weight is difficult under these circumstances of elevated mounting

Hydraulic actuators are most suitable for heavy load testing and are widely used in industrial and civil

engineering applications They canbeoperated at very low frequencies (almost direct current [DC]) aswell

as at intermediate frequencies (see Table 11) Large displacements (stroke) are possible at low frequencies

Hydraulic shakers have the advantage of providing high flexibility of operation during the test their

capabilities include variable-force and constant-force testing and wide-band random-input testing The

velocity and acceleration capabilities of hydraulic shakers are moderate Although any general excitation-

input motion (for example sine wave sine beat wide-band random) can be used in hydraulic shakers

faithful reproduction of these signals is virtually impossible at high frequencies because of distortion and

higher-order harmonics introduced by the high noise levels that are common in hydraulic systems This

is only a minor drawback in heavy-duty intermediate-frequency applications Dynamic interactions are

reduced through feedback control

1215 Inertial Shakers

In inertial shakers or ldquomechanical excitersrdquo the force that causes the shaker-table motion is generated by

inertia forces (accelerating masses) Counter-rotating-mass inertial shakers are typical in this category

To understand their principle of operation consider two equal masses rotating in opposite directions at

the same angular speed v and in the same circle of radius r (see Figure 16) This produces a resultant

force equal to 2mv2r cos vt in a fixed direction (the direction of symmetry of the two rotating arms)

Consequently a sinusoidal force with a frequency of v and an amplitude proportional to v2 is generated

This reaction force is applied to the shaker table

Figure 17 shows a sketch of a typical counter-rotating-mass inertial shaker It consists of two identical

rods rotating at the same speed in opposite directions Each rod has a series of slots in which to

Vibration Instrumentation 1-9

53191mdash522007mdash1201mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

place weights In this manner the magnitude of

the eccentric mass can be varied to achieve various

force capabilities The rods are driven by a

variable-speed electric motor through a gear

mechanism that usually provides several speed

ratios A speed ratio is selected depending on the

required test-frequency range The whole system is

symmetrically supported on a carriage that is

directly connected to the test table The test object

is mounted on the test table The preferred

mounting configuration is horizontal so that the

excitation force is applied to the test object in a

horizontal direction In this configuration there

are no variable gravity moments (weight pounddistance to center of gravity) acting on the drive

mechanism Figure 17 shows the vertical con-

figuration In dynamic testing of large structures

the carriage can be mounted directly on the

structure at a location where the excitation force

should be applied By incorporating two pairs of

counter-rotating masses it is possible to generate

test moments as well as test forces

FIGURE 15 A typical hydraulic shaker arrangement (a) schematic diagram (b) operational block diagram

m m

2mw2r cos wt

wtw w

wt

FIGURE 16 Principle of operation of a counter-

rotating-mass inertial shaker

Vibration Monitoring Testing and Instrumentation1-10

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copy 2007 by Taylor amp Francis Group LLC

Reaction-type shakers driven by inertia are widely used for the prototype testing of civil engineering

structures Their first application dates back to 1935 Inertial shakers are capable of producing

intermediate excitation forces The force generated is limited by the strength of the carriage frame The

frequency range of operation and the maximum velocity and acceleration capabilities are also

intermediate for inertial shakers whereas the maximum displacement capability is typically low A major

limitation of inertial shakers is that their excitation force is exclusively sinusoidal and that the force

amplitude is directly proportional to the square of the excitation frequency As a result complex and

random excitation testing constant-force testing (for example transmissibility tests and constant-force

sine-sweep tests) and flexibility to vary the force amplitude or the displacement amplitude during a test

are not generally feasible with this type of shakers Excitation frequency and amplitude can be varied

during testing however by incorporating a variable-speed drive for the motor The sinusoidal excitation

generated by inertial shakers is virtually undistorted which gives them an advantage over the other types

of shakers when used in sine-dwell and sine-sweep tests Small portable shakers with low-force capability

are available for use in on-site testing

1216 Electromagnetic Shakers

In electromagnetic shakers or ldquoelectrodynamic excitersrdquo the motion is generated using the principle of

operation of an electric motor Specifically the excitation force is produced when a variable excitation

signal (electrical) is passed through a moving coil placed in a magnetic field

The components of a commercial electromagnetic shaker are shown in Figure 18 A steady magnetic

field is generated by a stationary electromagnet that consists of field coils wound on a ferromagnetic base

that is rigidly attached to a protective shell structure The shaker head has a coil wound around it When

the excitation electrical signal is passed through this drive coil the shaker head which is supported on

flexure mounts will be set in motion The shaker head consists of the test table on which the test object

is mounted Shakers with interchangeable heads are available The choice of appropriate shaker head is

based on the geometry and mounting features of the test object The shaker head can be turned to

different angles by means of a swivel joint In this manner different directions of excitation (in biaxial

and triaxial testing) can be obtained

FIGURE 17 Sketch of a counter-rotating-mass inertial shaker

Vibration Instrumentation 1-11

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copy 2007 by Taylor amp Francis Group LLC

122 Dynamics of Electromagnetic Shakers

Consider a single axis electromagnetic shaker (Figure 18) with a test object having a single natural

frequency of importance within the test frequency range The dynamic interactions between the shaker

and the test object give rise to two significant natural frequencies (and correspondingly two significant

resonances) These appear as peaks in the frequency response curve of the test setup Furthermore the

natural frequency (resonance) of the test package alone causes a ldquotroughrdquo or depression (antiresonance)

in the frequency response curve of the overall test setup To explain this characteristic consider the

dynamic model shown in Figure 19 The following mechanical parameters are defined for

Figure 19(a) m k and b are the mass stiffness and equivalent viscous damping constant respectively

of the test package and me ke and be are the corresponding parameters of the exciter (shaker) Also in

the equivalent electrical circuit of the shaker head as shown in Figure 19(b) the following electrical

parameters are defined Re and Le are the resistance and (leakage) inductance and kb is the back

electromotive force (back emf) of the linear motor Assuming that the gravitational forces are supported

FIGURE 18 Schematic sectional view of a typical electromagnetic shaker manufactured by Bruel and Kjaer

Denmark

Vibration Monitoring Testing and Instrumentation1-12

53191mdash522007mdash1202mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

by the static deflections of the flexible elements and that the displacements are measured from the static

equilibrium position we have the following system equations

Test object meuroy frac14 2kethy2 yeTHORN2 beth_y2 _yeTHORN eth119THORNShaker head me euroye frac14 fe thorn kethy2 yeTHORN thorn beth_y2 _yeTHORN2 key 2 be _ye eth120THORN

Electrical Lediedt

thorn Reie thorn kb _ye frac14 vethtTHORN eth121THORN

The electromagnetic force fe generated in the shaker head is a result of the interaction of the magnetic

field generated by the current ie with coil of the moving shaker head and the constant magnetic field

(stator) in which the head coil is located Here we have

fe frac14 kbie eth122THORNNote that v(t) is the voltage signal that is applied by the amplifier to the shaker coil ye is the displacement

of the shaker head and y is the displacement response of the test package

It is assumed that kb has consistent electrical and mechanical units (Vmsec and NA) Usually

the electrical time constant of the shaker is quite small compared with the primarily mechanical

time constants of the shaker and the test package In such cases the Ledie=dt term in Equation 121 may

be neglected Consequently the equations from Equation 119 through Equation 122 may be

expressed in the Laplace (frequency) domain with the Laplace variable s taking the place of the derivative

d=dt as

ethms2 thorn bsthorn kTHORNy frac14 ethbsthorn kTHORNye eth123THORN

FIGURE 19 Dynamic models of an electromagnetic shaker and a flexible test package (a) mechanical model

(b) electrical model

Vibration Instrumentation 1-13

53191mdash522007mdash1202mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

frac12mes2 thorn ethbthorn beTHORNsthorn ethkthorn keTHORN ye frac14 ethbsthorn kTHORNy thorn kb

Rev2

k2bs

Reye eth124THORN

It follows that the transfer function of the shaker head motion with respect to the excitation voltage is

given by

yevfrac14 kb

Re

DethsTHORNDdethsTHORN eth125THORN

where DethsTHORN is the characteristic function of the primary dynamics of the test object

DethsTHORN frac14 ms2 thorn bsthorn k eth126THORN

and DdethsTHORN is the characteristic function of the primary dynamic interactions between the shaker and thetest object

DcethsTHORN frac14 mmes4 thorn frac12methbe thorn bthorn boTHORN thornmeb s

3 thorn frac12methke thorn kTHORN thornmekthorn bethbe thorn boTHORN s2thorn frac12bke thorn ethbe thorn boTHORNk sthorn kke

eth127THORN

where

bo frac14 k2bRe

eth128THORN

It is clear that under low damping conditions DdethsTHORN will produce two resonances as it is fourth order in sand similarly DethsTHORN will produce one antiresonance (trough) corresponding to the resonance of the testobject Note that in the frequency domain s frac14 jv and hence the frequency response function given by

Equation 125 is in fact

yevfrac14 kb

Rb

DethjvTHORNDdethjvTHORN eth129THORN

The magnitude of this frequency response function for a typical test system is sketched in Figure 110

Note that this curve is for the ldquoopen-looprdquo case where there is no feedback from the shaker controller

In practice the shaker controller will be able

to compensate for the resonances and anti-

resonances to some degree depending on its

effectiveness

The main advantages of electromagnetic

shakers are their high frequency range of

operation their high degree of operating flexi-

bility and the high level of accuracy of the

generated shaker motion Faithful reproduction

of complex excitations is possible because of the

advanced electronics and control systems used in

this type of shakers Electromagnetic shakers are

not suitable for heavy-duty applications (large test

objects) however High test-input accelerations

are possible at high frequencies when electromag-

netic shakers are used but their displacement and

velocity capabilities are limited to low or

intermediate values (see Table 11)

100

10

1 10 100Excitation Frequency (Hz)

Antiresonance

Resonance

Shak

erD

ispl

acem

entM

agni

tude

Resonance

1000

FIGURE 110 Frequency response curve of a typical

electromagnetic shaker with a test object

Vibration Monitoring Testing and Instrumentation1-14

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copy 2007 by Taylor amp Francis Group LLC

1221 Transient Exciters

Other varieties of exciters are commonly used in

transient-type vibration testing In these tests

either an impulsive force or an initial excitation is

applied to the test object and the resulting

response is monitored The excitations and the

responses are ldquotransientrdquo in this case Hammer

test drop tests and pluck tests fall into this

category For example a hammer test may be

conducted by hitting the object with an instru-

mented hammer and then measuring the response

of the object The hammer has a force sensor at its

tip as sketched in Figure 111 A piezoelectric or

strain-gage type force sensor may be used More

sophisticated hammers have impedance heads in

place of force sensors An impedance head

measures force and acceleration simultaneously

The results of a hammer test will depend on many

factors for example the dynamics of the hammer

body how firmly the hammer is held during the

impact how quickly the impact is applied and

whether there are multiple impacts

13 Control System

The two primary functions of the shaker control system in vibration testing are (1) to guarantee that the

specified excitation is applied to the test object and (2) to ensure that the dynamic stability (motion

constraints) of the test setup is preserved An operational block diagram illustrating these control

functions is given in Figure 112 The reference input to the control system represents the desired

excitation force that should be applied to the test object In the absence of any control however the force

reaching the test object will be distorted primarily because of (1) dynamic interactions and

nonlinearities of the shaker the test table the mounting fixtures the auxiliary instruments and the test

object itself (2) noise and errors in the signal generator amplifiers filters and other equipment and (3)

external loads and disturbances acting on the test object and other components (for example external

restraints aerodynamic forces friction) To compensate for these distorting factors response

measurements (displacements velocities acceleration and so on) are made at various locations in the

test setup and are used to control the system dynamics In particular the responses of the shaker the test

table and the test object are measured These responses are used to compare the actual excitation felt by

FIGURE 111 An instrumented hammer used in bump

tests or hammer tests

ExcitationInput

(Reference)

Feedback Paths

DriveSignal

ShakerResponse

TestTable

TestObject

Test ObjectResponse

Test TableResponseExciter

(Shaker)(Ram)

Controllerand

Amplifier

FIGURE 112 Operational block diagram illustrating a general shaker control system

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the test object at the shaker interface with the desired (specified) input The drive signal to the shaker is

modified depending on the error that is present

Two types of control are commonly employed in shaker apparatus simple manual control and

complex automatic control Manual control normally consists of simple open-loop trial-and-error

methods of manual adjustments (or calibration) of the control equipment to obtain a desired dynamic

response The actual response is usually monitored (on an oscilloscope or frequency analyzer screen for

example) during manual-control operations The pretest adjustments in manual control can be very

time-consuming as a result the test object might be subjected to overtesting which could produce

cumulative damage is undesirable and could defeat the test purpose Furthermore the calibration

procedure for the experimental setup must be repeated for each new test object

The disadvantages ofmanual control suggest that automatic control is desirable in complex test schemes

in which high accuracy of testing is desired The first step of automatic control involves automatic

measurement of the system response using control sensors and transducers The measurement is then fed

back into the control system which instantaneously determines the best drive signal to actuate the shaker

in order to get the desired excitation This may be done by either analog or digital methods

Primitive control systems require an accurate mathematical description of the test object This

dependency of the control system on the knowledge of test-object dynamics is clearly undesirable

Performance of a good control system should not be considerably affected by the dynamic interactions

and nonlinearities of the test object or by the nature of the excitation Proper selection of feedback signals

and control-system components can reduce such effects and will make the system robust

In the response-spectrum method of vibration testing it is customary to use displacement control at

low frequencies velocity control at intermediate frequency and acceleration control at high frequencies

This necessitates feedback of displacement velocity and acceleration responses Generally however the

most important feedback is the velocity feedback In sine-sweep tests the shaker velocity must change

steadily over the frequency band of interest In particular the velocity control must be precise near the

resonances of the test object Velocity (speed) feedback has a stabilizing effect on the dynamics which is

desirable This effect is particularly useful in ensuring stability in motion when testing is done near

resonances of lightly damped test objects On the contrary displacement (position) feedback can have a

destabilizing effect on some systems particularly when high feedback gains are used

The controller usually consists of various instruments equipment and computation hardware and

software Often the functions of the data-acquisition and processing system overlap with those of the

controller to some extent As an example consider the digital-controller of vibration testing apparatus

First the responses are measured through sensors (and transducers) filtered and amplified

(conditioned) These data channels may be passed through a multiplexer whose purpose is to select

one data channel at a time for processing Most modern data acquisition hardware does not need a

separate multiplexer to handle multiple signals The analog data are converted into digital data using

analog-to-digital converters (ADCs) The resulting sampled data are stored on a disk or as a block data in

the computer memory The reference input signal (typically a signal recorded on an FM tape) is also

sampled (if it is not already in the digital form) using an ADC and fed into the computer Digital

processing is done on the reference signal and the response data with the objective of computing the

command signal to drive the shaker The digital command signal is converted into an analog signal using

a digital-to-analog converter (DAC) and amplified (conditioned) before it is used to drive the exciter

The nature of the control components depends to a large extent on the nature and objectives of the

particular test to be conducted Some of the basic components in a shaker controller are described in

the following subsections

131 Components of a Shaker Controller

1311 Compressor

A compressor circuit is incorporated in automatic excitation control devices to control the excitation-

input level automatically The level of control depends on the feedback signal from a control sensor and

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the specified (reference) excitation signal Usually the compressor circuit is included in the excitation-

signal generator (for example in a sine generator) The control by this means may be done on the basis of

a single-frequency component (eg the fundamental frequency)

1312 Equalizer (Spectrum Shaper)

Random-signal equalizers are used to shape the spectrum of a random signal in a desired manner In

essence and equalizer consists of a bank of narrow-band filters (for example 80 filters) in parallel over

the operating frequency range By passing the signal through each filter the spectral density (or the mean

square value) of the signal in that narrow frequency band (for example each one-third-octave band) is

determined This is compared with the desired spectral level and automatic adjustment is made in that

filter in case there is an error In some systems response-spectrum analysis is made in place of power

spectral density analysis In that case the equalizer consists of a bank of simple oscillators whose

resonant frequencies are distributed over the operating frequency range of the equalizer The feedback

signal is passed through each oscillator and the peak value of its output is determined This value is

compared with the desired response spectrum value at that frequency If there is an error automatic gain

adjustment is made in the appropriate excitation signal components

Random-noise equalizers are used in conjunction with random signal generators They receive

feedback signals from the control sensors In some digital control systems there are algorithms (software)

that are used to iteratively converge the spectrum of the excitation signal felt by the test object into the

desired spectrum

1313 Tracking Filter

Many vibration tests are based on single-frequency excitations In such cases the control functions

should be performed on the basis of the amplitudes of the fundamental-frequency component of the

signal A tracking filter is simply a frequency-tuned band-pass filter It automatically tunes the center

frequency of its very narrow-band-pass filter to the frequency of a carrier signal Then when a noisy

signal is passed through the tuned filter the output of the filter will be the required fundamental

frequency component in the signal Tracking filters also are useful in obtaining amplitudendashfrequency

plots using an XndashY plotter In such cases the frequency value comes from the signal generator (sweep

oscillator) which produces the carrier signal to the tracking filter The tracking filter then determines the

corresponding amplitude of a signal that is fed into it Most tracking filters have dual channels so that two

signals can be handled (tracked) simultaneously

1314 Excitation Controller (Amplitude Servo-Monitor)

An excitation controller is typically an integral part of the signal generator It can be set so that automatic

sweep between two frequency limits can be performed at a selected sweep rate (linear or logarithmic)

More advanced excitation controllers have the capability of an automatic switch-over between constant-

displacement constant-velocity and constant-acceleration excitation-input control at specified

frequencies over the sweep frequency interval Consequently integrator circuits should be present

within the excitation controller unit to determine velocities and displacements from acceleration signals

Sometimes integration is performed by a separate unit called a vibration meter This unit also offers

the operator the capability of selecting the desired level of each signal (acceleration velocity or

displacement) There is an automatic cut-off level for large displacement values that could result from

noise in acceleration signals A compressor is also a subcomponent of the excitation controller The

complete unit is sometimes known as an amplitude servo-monitor

132 Signal-Generating Equipment

Shakers are force-generating devices that are operated using drive (excitation) signals generated from a

source The excitation-signal source is known as the signal generator Three major types of signal

generators are used in vibration testing applications (1) oscillators (2) random-signal generators and

(3) storage devices In some units oscillators and random-signal generators are combined We shall

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discuss these two generators separately however because of their difference in function It also should be

noted that almost any digital signal (deterministic or random) can be generated by a digital computer

using a suitable computer program the signal eventually can be passed through a DAC to obtain

the corresponding analog signal These lsquodigitalrsquo signal generators along with analog sources such as

magnetic tape players (FM) are classified into the category of storage devices

The dynamic range of equipment is the ratio of the maximum and minimum output levels (expressed

in decibels) at which it is capable of operating without significant error This is an important specification

for many types of equipment particularly for signal-generating devices The output level of the signal

generator should be set to a value within its dynamic range

1321 Oscillators

Oscillators are essentially single-frequency generators Typically sine signals are generated but other

waveforms (such as rectangular and triangular pulses) are also available in most oscillators Normally

an oscillator has two modes of operation (1) sweeping up and down between two frequency limits and

(2) dwelling at a specified frequency In the sweep operation the sweep rate should be specified This can

be done either on a linear scale (Hzmin) or on a logarithmic scale (octavesmin) In the dwell operation

the frequency points (or intervals) should be specified In either case a desired signal level can be chosen

using the gain-control knob An oscillator that is operated exclusively in the sweep mode is called a sweep

oscillator

The early generation of oscillators employed variable inductor-capacitor types of electronic circuits to

generate signals oscillating at a desired frequency The oscillator is tuned to the required frequency by

varying the capacitance or inductance parameters A DC voltage is applied to energize the capacitor

and to obtain the desired oscillating voltage signal which subsequently is amplified and conditioned

Modern oscillators use operational amplifier circuits along with resistor capacitor and semiconductor

(SC) elements Also common are crystal (quartz) parallel-resonance oscillators used to generate voltage

signals accurately at a fixed frequency The circuit is activated using a DC-voltage source Other

frequencies of interest are obtained by passing this high-frequency signal through a frequency converter

The signal is then conditioned (amplified and filtered) Required shaping (for example rectangular

pulse) is obtained using a shape circuit Finally the required signal level is obtained by passing the

resulting signal through a variable-gain amplifier A block diagram of an oscillator illustrating various

stages in the generation of a periodic signal is given in Figure 113

A typical oscillator offers a choice of several (typically six) linear and logarithmic frequency ranges and

a sizable level of control capability (for example 80 dB) Upper and lower frequency limits in a sweep can

be preset on the front panel to any of the available frequency ranges Sweep-rate settings are continuously

DC Voltage

Oscillator

FrequencySpecification

FrequencyConverter

FilterAmplifier

ShaperPeriodicSignal

FrequencyCounter

Fixed-FrequencySignal

Variable-GainOutput

Amplifier

SignalSpecification

LevelSpecification

FIGURE 113 Block diagram of an oscillator-type signal generator

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  • 53191fm
    • Vibration Monitoring Testing and Instrumentation
      • Preface
      • Acknowledgments
      • Editor-in-Chief
      • Contributors
      • Contents
      • Related Titles
          • 53191ch1
            • Table of Contents
            • Chapter 1 Vibration Instrumentation
              • Summary
              • 11 Introduction
              • 12 Vibration Exciters
                • 121 Shaker Selection
                  • 1211 Force Rating
                  • 1212 Power Rating
                  • 1213 Stroke Rating
                  • 1214 Hydraulic Shakers
                  • 1215 Inertial Shakers
                  • 1216 Electromagnetic Shakers
                    • 122 Dynamics of Electromagnetic Shakers
                      • 1221 Transient Exciters
                          • 13 Control System
                            • 131 Components of a Shaker Controller
                              • 1311 Compressor
                              • 1312 Equalizer (Spectrum Shaper)
                              • 1313 Tracking Filter
                              • 1314 Excitation Controller (Amplitude Servo-Monitor)
                                • 132 Signal-Generating Equipment
                                  • 1321 Oscillators
                                  • 1322 Random Signal Generators
                                  • 1323 Tape Players
                                  • 1324 Data Processing
                                      • 14 Performance Specification
                                        • 141 Parameters for Performance Specification
                                          • 1411 Time-Domain Specifications
                                          • 1412 Frequency-Domain Specifications
                                            • 142 Linearity
                                            • 143 Instrument Ratings
                                              • 1431 Rating Parameters
                                                • 144 Accuracy and Precision
                                                  • 15 Motion Sensors and Transducers
                                                    • 151 Potentiometer
                                                      • 1511 Potentiometer Resolution
                                                      • 1512 Optical Potentiometer
                                                        • 152 Variable-Inductance Transducers
                                                          • 1521 Mutual-Induction Transducers
                                                          • 1522 Linear-Variable Differential Transformer
                                                          • 1523 Signal Conditioning
                                                            • 153 Mutual-Induction Proximity Sensor
                                                            • 154 Selfinduction Transducers
                                                            • 155 Permanent-Magnet Transducers
                                                            • 156 Alternating Current Permanent-Magnet Tachometer
                                                            • 157 Alternating Current Induction Tachometer
                                                            • 158 Eddy Current Transducers
                                                            • 159 Variable-Capacitance Transducers
                                                              • 1591 Capacitive Displacement Sensors
                                                              • 1592 Capacitive Angular Velocity Sensor
                                                              • 1593 Capacitance Bridge Circuit
                                                                • 1510 Piezoelectric Transducers
                                                                  • 15101 Sensitivity
                                                                  • 15102 Piezoelectric Accelerometer
                                                                  • 15103 Charge Amplifier
                                                                      • 16 Torque Force and Other Sensors
                                                                        • 161 Strain Gage Sensors
                                                                          • 1611 Equations for Strain Gage Measurements
                                                                          • 1612 Bridge Sensitivity
                                                                          • 1613 The Bridge Constant
                                                                          • 1614 The Calibration Constant
                                                                          • 1615 Data Acquisition
                                                                          • 1616 Accuracy Considerations
                                                                          • 1617 Semiconductor Strain Gages
                                                                          • 1618 Force and Torque Sensors
                                                                          • 1619 Strain Gage Torque Sensors
                                                                          • 16110 Deflection Torque Sensors
                                                                          • 16111 Variable-Reluctance Torque Sensor
                                                                          • 16112 Reaction Torque Sensors
                                                                            • 162 Miscellaneous Sensors
                                                                              • 1621 Stroboscope
                                                                              • 1622 Fiber Optic Sensors and Lasers
                                                                              • 1623 Fiber-Optic Gyroscope
                                                                              • 1624 Laser Doppler Interferometer
                                                                              • 1625 Ultrasonic Sensors
                                                                              • 1626 Gyroscopic Sensors
                                                                                  • References
                                                                                  • Appendix 1A Virtual Instrumentation for Data Acquisition Analysis and Presentation
                                                                                    • Summary
                                                                                    • List of Abbreviations
                                                                                    • 1A1 Dynamic Signals
                                                                                      • 1A11 Acquiring and Simulating Dynamic Signals
                                                                                        • 1A111 Aliasing
                                                                                        • 1A112 Time Continuity
                                                                                            • 1A2 Measurement Configuration Considerations
                                                                                              • 1A21 Input Signal Considerations
                                                                                                • 1A211 Input Pseudodifferential and Differential Configuration
                                                                                                • 1A212 Gain
                                                                                                • 1A213 Input Coupling
                                                                                                • 1A214 Integrated Electronic Piezoelectric Excitation
                                                                                                • 1A215 Nyquist Frequency and Bandwidth
                                                                                                • 1A216 Analog-to-Digital Conversion
                                                                                                • 1A217 Antialias Filters
                                                                                                • 1A218 Input Filter Delay
                                                                                                • 1A219 Overload Detection
                                                                                                  • 1A22 Output Signal Considerations
                                                                                                    • 1A221 Output Pseudodifferential and Differential Configuration
                                                                                                    • 1A222 Attenuation
                                                                                                    • 1A223 Digital-to-Analog Conversion
                                                                                                    • 1A224 Anti-imaging and Interpolation Filters
                                                                                                    • 1A225 Output Filter Delay
                                                                                                        • 1A3 Scaling and Calibration
                                                                                                          • 1A31 Scaling to Engineering Units
                                                                                                          • 1A32 Performing System Calibration
                                                                                                            • 1A321 Propagation Delay Calibration
                                                                                                                • 1A4 Limit Testing Analysis
                                                                                                                  • 1A41 Limit Testing Overview
                                                                                                                  • 1A42 Using the SVT Limit Testing VI
                                                                                                                    • 1A5 Integration
                                                                                                                      • 1A51 Introduction to Integration
                                                                                                                      • 1A52 Implementing Integration
                                                                                                                        • 1A521 Challenges when Integrating Vibration Data
                                                                                                                          • 1A53 Time-Domain Integration
                                                                                                                            • 1A531 Single-Shot Acquisition and Integration
                                                                                                                            • 1A532 Continuous Acquisition and Integration
                                                                                                                              • 1A54 Frequency-Domain Integration
                                                                                                                                • 1A6 Vibration-Level Measurements
                                                                                                                                  • 1A61 Measuring the Root Mean Square Level
                                                                                                                                    • 1A611 Single-Shot Buffered Acquisition
                                                                                                                                    • 1A612 Continuous Signal Acquisition
                                                                                                                                      • 1A62 Performing a Running RMS Level Measurement
                                                                                                                                      • 1A63 Computing the Peak Level
                                                                                                                                      • 1A64 Computing the Crest Factor
                                                                                                                                        • 1A7 Frequency Analysis
                                                                                                                                          • 1A71 FFT Fundamentals
                                                                                                                                            • 1A711 Number of Samples
                                                                                                                                            • 1A712 Frequency Resolution
                                                                                                                                            • 1A713 Maximum Resolvable Frequency
                                                                                                                                            • 1A714 Minimum Resolvable Frequency
                                                                                                                                            • 1A715 Number of Spectral Lines
                                                                                                                                            • 1A716 Relationship between Time-Domain and Frequency-Domain Specifications and Parameters
                                                                                                                                              • 1A72 Increasing Frequency Resolution
                                                                                                                                                • 1A721 Zoom FFT Analysis
                                                                                                                                                • 1A722 Frequency Resolution of the Zoom FFT VIs
                                                                                                                                                • 1A723 Zoom Measurement
                                                                                                                                                • 1A724 Zoom Settings
                                                                                                                                                • 1A725 Subset Analysis
                                                                                                                                                    • 1A8 Transient Analysis
                                                                                                                                                      • 1A81 Transient Analysis with the Sound and Vibration Toolkit
                                                                                                                                                      • 1A82 Performing an STFT vs Time
                                                                                                                                                        • 1A821 Selecting the FFT Block Size
                                                                                                                                                        • 1A822 Overlapping
                                                                                                                                                        • 1A823 Using the SVT STFT vs Time VI
                                                                                                                                                          • 1A83 Performing an STFT vs Rotational Speed
                                                                                                                                                            • 1A831 Converting the Pulse Train to Rotational Speed
                                                                                                                                                            • 1A832 STFT vs RPM
                                                                                                                                                              • 1A84 Measuring a Shock Response Spectrum
                                                                                                                                                                • 1A9 Waterfall Display
                                                                                                                                                                  • 1A91 Using the Display VIs
                                                                                                                                                                    • 1A911 Initializing the Display
                                                                                                                                                                    • 1A912 Sending Data to the Display
                                                                                                                                                                    • 1A913 Waterfall Display for Frequency Analysis
                                                                                                                                                                    • 1A914 Waterfall Display for Transient Analysis
                                                                                                                                                                    • 1A915 Waterfall Display for Octave Spectra
                                                                                                                                                                        • 1A10 Swept-Sine Measurements
                                                                                                                                                                          • 1A101 Swept-Sine Overview
                                                                                                                                                                          • 1A102 Choosing Swept-Sine vs FFT Measurements
                                                                                                                                                                          • 1A103 Taking a Swept-Sine Measurement
                                                                                                                                                                          • 1A104 Swept-Sine Measurement Example
                                                                                                                                                                              • Bibliography
                                                                                                                                                                              • Related Titles
                                                                                                                                                                                  • 53191ch2
                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                    • Chapter 2 Signal Conditioning and Modification
                                                                                                                                                                                      • Summary
                                                                                                                                                                                      • 21 Introduction
                                                                                                                                                                                      • 22 Amplifiers
                                                                                                                                                                                        • 221 Operational Amplifier
                                                                                                                                                                                        • 222 Use of Feedback in Opamp
                                                                                                                                                                                        • 223 Voltage Current and Power Amplifiers
                                                                                                                                                                                          • 2231 Charge Amplifiers
                                                                                                                                                                                            • 224 Instrumentation Amplifiers
                                                                                                                                                                                              • 2241 Differential Amplifier
                                                                                                                                                                                              • 2242 Common Mode
                                                                                                                                                                                                • 225 Amplifier Performance Ratings
                                                                                                                                                                                                  • 2251 Common-Mode Rejection Ratio
                                                                                                                                                                                                    • 226 Component Interconnection
                                                                                                                                                                                                      • 2261 Impedance Characteristics
                                                                                                                                                                                                      • 2262 Cascade Connection of Devices
                                                                                                                                                                                                      • 2263 AC-Coupled Ampliers
                                                                                                                                                                                                          • 23 Analog Filters
                                                                                                                                                                                                            • 231 Passive Filters and Active Filters
                                                                                                                                                                                                              • 2311 Number of Poles
                                                                                                                                                                                                                • 232 Low-Pass Filters
                                                                                                                                                                                                                  • 2321 Low-Pass Butterworth Filter
                                                                                                                                                                                                                    • 233 High-Pass Filters
                                                                                                                                                                                                                    • 234 Band-Pass Filters
                                                                                                                                                                                                                      • 2341 Resonance-Type Band-Pass Filters
                                                                                                                                                                                                                        • 235 Band-Reject Filters
                                                                                                                                                                                                                          • 24 Modulators and Demodulators
                                                                                                                                                                                                                            • 241 Amplitude Modulation
                                                                                                                                                                                                                              • 2411 Modulation Theorem
                                                                                                                                                                                                                              • 2412 Side Frequencies and Side Bands
                                                                                                                                                                                                                                • 242 Application of Amplitude Modulation
                                                                                                                                                                                                                                  • 2421 Fault Detection and Diagnosis
                                                                                                                                                                                                                                    • 243 Demodulation
                                                                                                                                                                                                                                      • 25 Analog ndashDigital Conversion
                                                                                                                                                                                                                                        • 251 Digital-to-Analog Conversion
                                                                                                                                                                                                                                          • 2511 DAC Error Sources
                                                                                                                                                                                                                                            • 252 Analog-to-Digital Conversion
                                                                                                                                                                                                                                            • 253 Analog-to-Digital Converter Performance Characteristics
                                                                                                                                                                                                                                              • 2531 Resolution and Quantization Error
                                                                                                                                                                                                                                              • 2532 Monotonicity Nonlinearity and Offset Error
                                                                                                                                                                                                                                              • 2533 Analog-to-Digital Converter Conversion Rate
                                                                                                                                                                                                                                                • 254 Sample-and-Hold Circuitry
                                                                                                                                                                                                                                                • 255 Digital Filters
                                                                                                                                                                                                                                                  • 2551 Software Implementation and Hardware Implementation
                                                                                                                                                                                                                                                      • 26 Bridge Circuits
                                                                                                                                                                                                                                                        • 261 Wheatstone Bridge
                                                                                                                                                                                                                                                        • 262 Constant-Current Bridge
                                                                                                                                                                                                                                                        • 263 Bridge Amplifiers
                                                                                                                                                                                                                                                          • 2631 Half-Bridge Circuits
                                                                                                                                                                                                                                                            • 264 Impedance Bridges
                                                                                                                                                                                                                                                              • 2641 Owen Bridge
                                                                                                                                                                                                                                                              • 2642 Wien-Bridge Oscillator
                                                                                                                                                                                                                                                                  • 27 Linearizing Devices
                                                                                                                                                                                                                                                                    • 271 Linearization by Software
                                                                                                                                                                                                                                                                    • 272 Linearization by Hardware Logic
                                                                                                                                                                                                                                                                    • 273 Analog Linearizing Circuitry
                                                                                                                                                                                                                                                                    • 274 Offsetting Circuitry
                                                                                                                                                                                                                                                                    • 275 Proportional-Output Circuitry
                                                                                                                                                                                                                                                                      • 2751 Curve-Shaping Circuitry
                                                                                                                                                                                                                                                                          • 28 Miscellaneous Signal Modification Circuitry
                                                                                                                                                                                                                                                                            • 281 Phase Shifters
                                                                                                                                                                                                                                                                            • 282 Voltage-to-Frequency Converter
                                                                                                                                                                                                                                                                            • 283 Frequency-to-Voltage Converter
                                                                                                                                                                                                                                                                            • 284 Voltage-to-Current Converters
                                                                                                                                                                                                                                                                            • 285 Peak-Hold Circuits
                                                                                                                                                                                                                                                                              • 29 Signal Analyzers and Display Devices
                                                                                                                                                                                                                                                                                • 291 Signal Analyzers
                                                                                                                                                                                                                                                                                • 292 Oscilloscopes
                                                                                                                                                                                                                                                                                  • 2921 Triggering
                                                                                                                                                                                                                                                                                  • 2922 Lissajous Patterns
                                                                                                                                                                                                                                                                                  • 2923 Digital Oscilloscopes
                                                                                                                                                                                                                                                                                      • Bibliography
                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                          • 53191ch3
                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                            • Chapter 3 Vibration Testing
                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                              • 31 Introduction
                                                                                                                                                                                                                                                                                              • 32 Representation of a Vibration Environment
                                                                                                                                                                                                                                                                                                • 321 Test Signals
                                                                                                                                                                                                                                                                                                  • 3211 Stochastic vs Deterministic Signals
                                                                                                                                                                                                                                                                                                    • 322 Deterministic Signal Representation
                                                                                                                                                                                                                                                                                                      • 3221 Single-Frequency Signals
                                                                                                                                                                                                                                                                                                      • 3222 Sine Sweep
                                                                                                                                                                                                                                                                                                      • 3223 Sine Dwell
                                                                                                                                                                                                                                                                                                      • 3224 Decaying Sine
                                                                                                                                                                                                                                                                                                      • 3225 Sine Beat
                                                                                                                                                                                                                                                                                                      • 3226 Sine Beat with Pauses
                                                                                                                                                                                                                                                                                                      • 3227 Multifrequency Signals
                                                                                                                                                                                                                                                                                                      • 3228 Actual Excitation Records
                                                                                                                                                                                                                                                                                                      • 3229 Simulated Excitation Signals
                                                                                                                                                                                                                                                                                                        • 323 Stochastic Signal Representation
                                                                                                                                                                                                                                                                                                          • 3231 Ergodic Random Signals
                                                                                                                                                                                                                                                                                                          • 3232 Stationary Random Signals
                                                                                                                                                                                                                                                                                                          • 3233 Independent and Uncorrelated Signals
                                                                                                                                                                                                                                                                                                          • 3234 Transmission of Random Excitations
                                                                                                                                                                                                                                                                                                            • 324 Frequency-Domain Representations
                                                                                                                                                                                                                                                                                                              • 3241 Fourier Spectrum Method
                                                                                                                                                                                                                                                                                                              • 3242 Power Spectral Density Method
                                                                                                                                                                                                                                                                                                                • 325 Response Spectrum
                                                                                                                                                                                                                                                                                                                  • 3251 Displacement Velocity and Acceleration Spectra
                                                                                                                                                                                                                                                                                                                  • 3252 Response-Spectra Plotting Paper
                                                                                                                                                                                                                                                                                                                  • 3253 Zero-Period Acceleration
                                                                                                                                                                                                                                                                                                                  • 3254 Uses of Response Spectra
                                                                                                                                                                                                                                                                                                                    • 326 Comparison of Various Representations
                                                                                                                                                                                                                                                                                                                      • 33 Pretest Procedures
                                                                                                                                                                                                                                                                                                                        • 331 Purpose of Testing
                                                                                                                                                                                                                                                                                                                        • 332 Service Functions
                                                                                                                                                                                                                                                                                                                          • 3321 Active Equipment
                                                                                                                                                                                                                                                                                                                          • 3322 Passive Equipment
                                                                                                                                                                                                                                                                                                                          • 3323 Functional Testing
                                                                                                                                                                                                                                                                                                                            • 333 Information Acquisition
                                                                                                                                                                                                                                                                                                                              • 3331 Interface Details
                                                                                                                                                                                                                                                                                                                              • 3332 Effect of Neglecting Interface Dynamics
                                                                                                                                                                                                                                                                                                                              • 3333 Effects of Damping
                                                                                                                                                                                                                                                                                                                              • 3334 Effects of Inertia
                                                                                                                                                                                                                                                                                                                              • 3335 Effect of Natural Frequency
                                                                                                                                                                                                                                                                                                                              • 3336 Effect of Excitation Frequency
                                                                                                                                                                                                                                                                                                                              • 3337 Other Effects of Interface
                                                                                                                                                                                                                                                                                                                                • 334 Test-Program Planning
                                                                                                                                                                                                                                                                                                                                  • 3341 Testing of Cabinet-Mounted Equipment
                                                                                                                                                                                                                                                                                                                                    • 335 Pretest Inspection
                                                                                                                                                                                                                                                                                                                                      • 34 Testing Procedures
                                                                                                                                                                                                                                                                                                                                        • 341 Resonance Search
                                                                                                                                                                                                                                                                                                                                        • 342 Methods of Determining Frequency-Response Functions
                                                                                                                                                                                                                                                                                                                                          • 3421 Fourier Transform Method
                                                                                                                                                                                                                                                                                                                                          • 3422 Spectral Density Method
                                                                                                                                                                                                                                                                                                                                          • 3423 Harmonic Excitation Method
                                                                                                                                                                                                                                                                                                                                            • 343 Resonance-Search Test Methods
                                                                                                                                                                                                                                                                                                                                              • 3431 Hammer (Bump) Test and Drop Test
                                                                                                                                                                                                                                                                                                                                              • 3432 Pluck Test
                                                                                                                                                                                                                                                                                                                                              • 3433 Shaker Tests
                                                                                                                                                                                                                                                                                                                                                • 344 Mechanical Aging
                                                                                                                                                                                                                                                                                                                                                  • 3441 Equivalence for Mechanical Aging
                                                                                                                                                                                                                                                                                                                                                  • 3442 Excitation-Intensity Equivalence
                                                                                                                                                                                                                                                                                                                                                  • 3443 Dynamic-Excitation Equivalence
                                                                                                                                                                                                                                                                                                                                                  • 3444 Cumulative Damage Theory
                                                                                                                                                                                                                                                                                                                                                    • 345 Test-Response Spectrum Generation
                                                                                                                                                                                                                                                                                                                                                    • 346 Instrument Calibration
                                                                                                                                                                                                                                                                                                                                                    • 347 Test-Object Mounting
                                                                                                                                                                                                                                                                                                                                                    • 348 Test-Input Considerations
                                                                                                                                                                                                                                                                                                                                                      • 3481 Test Nomenclature
                                                                                                                                                                                                                                                                                                                                                      • 3482 Testing with Uncorrelated Excitations
                                                                                                                                                                                                                                                                                                                                                      • 3483 Symmetrical Rectilinear Testing
                                                                                                                                                                                                                                                                                                                                                      • 3484 Geometry vs Dynamics
                                                                                                                                                                                                                                                                                                                                                      • 3485 Some Limitations
                                                                                                                                                                                                                                                                                                                                                      • 3486 Testing Black Boxes
                                                                                                                                                                                                                                                                                                                                                      • 3487 Phasing of Excitations
                                                                                                                                                                                                                                                                                                                                                      • 3488 Testing a Gray or White Box
                                                                                                                                                                                                                                                                                                                                                      • 3489 Overtesting in Multitest Sequences
                                                                                                                                                                                                                                                                                                                                                          • 35 Some Practical Information
                                                                                                                                                                                                                                                                                                                                                            • 351 Random Vibration Test Example
                                                                                                                                                                                                                                                                                                                                                            • 352 Vibration Shakers and Control Systems
                                                                                                                                                                                                                                                                                                                                                              • Bibliography
                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                  • 53191ch4
                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                    • Chapter 4 Experimental Modal Analysis
                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                      • 41 Introduction
                                                                                                                                                                                                                                                                                                                                                                      • 42 Frequency-Domain Formulation
                                                                                                                                                                                                                                                                                                                                                                        • 421 Transfer-Function Matrix
                                                                                                                                                                                                                                                                                                                                                                        • 422 Principle of Reciprocity
                                                                                                                                                                                                                                                                                                                                                                          • 43 Experimental Model Development
                                                                                                                                                                                                                                                                                                                                                                            • 431 Extraction of the Time-Domain Model
                                                                                                                                                                                                                                                                                                                                                                              • 44 Curve Fitting of Transfer Functions
                                                                                                                                                                                                                                                                                                                                                                                • 441 Problem Identification
                                                                                                                                                                                                                                                                                                                                                                                • 442 Single- and Multi-Degree-of-Freedom Techniques
                                                                                                                                                                                                                                                                                                                                                                                • 443 Single-Degree-of-Freedom Parameter Extraction in the Frequency Domain
                                                                                                                                                                                                                                                                                                                                                                                  • 4431 Circle-Fit Method
                                                                                                                                                                                                                                                                                                                                                                                    • Case of Viscous Damping
                                                                                                                                                                                                                                                                                                                                                                                    • Case of Hysteretic Damping
                                                                                                                                                                                                                                                                                                                                                                                      • 4432 Peak-Picking Method
                                                                                                                                                                                                                                                                                                                                                                                        • 444 Multi-Degree of Freedom Curve Fitting
                                                                                                                                                                                                                                                                                                                                                                                          • 4441 Formulation of the Method
                                                                                                                                                                                                                                                                                                                                                                                            • 445 A Comment on Static Modes and Rigid-Body Modes
                                                                                                                                                                                                                                                                                                                                                                                            • 446 Residue Extraction
                                                                                                                                                                                                                                                                                                                                                                                              • 45 Laboratory Experiments
                                                                                                                                                                                                                                                                                                                                                                                                • 451 Lumped-Parameter System
                                                                                                                                                                                                                                                                                                                                                                                                  • 4511 Frequency-Domain Test
                                                                                                                                                                                                                                                                                                                                                                                                  • 4512 Time-Domain Tests
                                                                                                                                                                                                                                                                                                                                                                                                    • 452 Distributed-Parameter System
                                                                                                                                                                                                                                                                                                                                                                                                      • 46 Commercial EMA Systems
                                                                                                                                                                                                                                                                                                                                                                                                        • 461 System Configuration
                                                                                                                                                                                                                                                                                                                                                                                                          • 4611 FFT Analysis Options
                                                                                                                                                                                                                                                                                                                                                                                                          • 4612 Modal Analysis Components
                                                                                                                                                                                                                                                                                                                                                                                                              • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                  • 53191ch5
                                                                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                    • Chapter 5 Mechanical Shock
                                                                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                      • 51 Definitions
                                                                                                                                                                                                                                                                                                                                                                                                                        • 511 Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 512 Simple (or Perfect) Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 513 Half-Sine Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 514 Versed-Sine (or Haversine) Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 515 Terminal Peak Sawtooth Shock or Final Peak Sawtooth Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 516 Rectangular Shock
                                                                                                                                                                                                                                                                                                                                                                                                                          • 5161 Trapezoidal Shock
                                                                                                                                                                                                                                                                                                                                                                                                                              • 52 Description in the Time Domain
                                                                                                                                                                                                                                                                                                                                                                                                                              • 53 Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                • 531 Need
                                                                                                                                                                                                                                                                                                                                                                                                                                • 532 Shock Response Spectrum Definition
                                                                                                                                                                                                                                                                                                                                                                                                                                • 533 Response of a Linear One-Degree-of-Freedom System
                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5331 Shock Defined by a Force
                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5332 Shock Defined by an Acceleration
                                                                                                                                                                                                                                                                                                                                                                                                                                    • 534 Definitions
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5341 Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5342 Absolute Acceleration Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5343 Relative Displacement Shock Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5344 Primary Positive Shock Response Spectrum or Initial Positive Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5345 Primary (or Initial) Negative Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5346 Secondary (or Residual) Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5347 Positive (or Maximum Positive) Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5348 Negative (or Maximum Negative) Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5349 Maximax Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53410 Choice of Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                        • 535 Standardized Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5351 Definition
                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5352 Standardized Shock Response Spectra of Simple Shocks
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53521 Half-Sine Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53522 Versed Sine Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53523 Terminal Peak Sawtooth Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53524 Rectangular Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53525 Trapezoidal Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 536 Choice of Damping
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 537 Shock Response Spectra Domains
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 538 Algorithms for Calculation of the Shock Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 539 Choice of the Digitization Frequency of the Signal
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5310 Use of Shock Response Spectra for the Study of Systems with Several Degrees of Freedom
                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 54 Pyroshocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 55 Use of Shock Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 551 Severity Comparison of Several Shocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 552 Test Specification Development from Real Environment Data
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5521 Synthesis of Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5522 Nature of the Specification
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5523 Choice of Shape
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5524 Amplitude
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5525 Duration
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5526 Difficulties
                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 56 Standards
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 561 Types of Standards
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 562 Installation Conditions of Test Item
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 563 Uncertainty Factor
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 564 Bump Test
                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 57 Damage Boundary Curve
                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 571 Definition
                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 572 Analysis of Test Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 58 Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 581 Main Types
                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 582 Impact Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5821 Universal Shock-Test Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 58211 Impact Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 58212 Impulse Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 583 Shock Simulators (Programmers)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5831 Half-Sine Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58311 Shock Duration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58312 Impact Velocity
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58313 Maximum Deformation of the Shock Simulator (Programmer)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58314 Shock Amplitude
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58315 Characteristics of the Target
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5832 Terminal Peak Sawtooth Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5833 Rectangular Pulse ndash Trapezoidal Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5834 Universal Shock Simulator (Programmer)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 58341 Generating a Half-Sine Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 58342 Generating a Terminal Peak Sawtooth Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 58343 Trapezoidal Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 584 Limitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5841 Limitations of the Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5842 Limitations of Shock Simulators
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 585 Pneumatic Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 586 High Impact Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5861 Lightweight High Impact Shock Machine
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5862 Medium Weight High Impact Shock Machine
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 587 Specific Test Facilities
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 59 Generation of Shock Using Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 591 Principle Behind the Generation of a Simple Shape Signal versus Time
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 592 Main Advantages
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 593 Pre- and Postshocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5931 Requirements
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5932 Solutions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 59321 Optimized Pre- and Postpulses
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5933 Incidence on the Shock Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 594 Limitations of Electrodynamic Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5941 Mechanical Limitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 59411 Abacuses
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5942 Electronic Limitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 595 The Use of Electrohydraulic Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 510 Control by a Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 5101 Principle
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 5102 Principal Shapes of Elementary Signals
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 51021 Decaying Sinusoid
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 51022 ZERD Function
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 51023 WAVSIN Waveform
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 5103 Comparison of WAVSIN SHOC Waveforms and Decaying Sinusoid
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 5104 Criticism of Control by a Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 511 Pyrotechnic Shock Simulation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5111 Simulation Using Pyrotechnic Facilities
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5112 Simulation Using Metal-to-Metal Impact
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5113 Simulation Using Electrodynamic Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5114 Simulation Using Conventional Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53191ch6
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Chapter 6 Machine Condition Monitoring and Fault Diagnostics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 61 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 62 Machinery Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 621 Causes of Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 622 Types of Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 623 Frequency of Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 63 Basic Maintenance Strategies
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 631 Run-to-Failure (Breakdown) Maintenance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 632 Scheduled (Preventative) Maintenance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 633 Condition-Based (Predictive Proactive Reliability Centered On-Condition) Maintenance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 64 Factors Which Influence Maintenance Strategy
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 65 Machine Condition Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 651 Periodic Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 652 Continuous Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 66 Transducer Selection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 661 Noncontact Displacement Transducers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 662 Velocity Transducers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 663 Acceleration Transducers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 67 Transducer Location
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 68 Recording and Analysis Instrumentation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 681 Vibration Meters
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 682 Data Collectors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 683 Frequency-Domain Analyzers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 684 Time-Domain Instruments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 685 Tracking Analyzers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 69 Display Formats and Analysis Tools
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 691 Time Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6911 Time-Waveform Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6912 Time-Waveform Indices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6913 Time-Synchronous Averaging
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6914 Negative Averaging
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6915 Orbits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6916 Probability Density Functions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6917 Probability Density Moments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 692 Frequency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6921 Band-Pass Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6922 Shock Pulse (Spike Energy)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6923 Enveloped Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6924 Signature Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6925 Cascades (Waterfall Plots)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6926 Masks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6927 Frequency-Domain Indices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 693 Modal Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 694 Quefrency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 610 Fault Detection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 6101 Standards
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61011 Standards Based on Machinery Type
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61012 Standards Based on Vibration Severity
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 6102 Acceptance Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 61021 Statistical Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 6103 Frequency-Domain Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61031 Limited Band Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61032 Constant Bandwidth Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61033 Constant Percentage Bandwidth Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 611 Fault Diagnostics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 6111 Forcing Functions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61111 Unbalance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61112 Misalignment
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61113 Mechanical Looseness
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61114 Soft Foot
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61115 Rubs
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61116 Resonances
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61117 Oil Whirl
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61118 Oil Whip
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61119 Structural Vibrations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 611110 Foundation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 6112 Specific Machine Components
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 61121 Damaged or Worn Rolling-Element Bearings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 61122 Damaged or Worn Gears
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 6113 Specific Machine Types
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61131 Pumps
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61132 Fans
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61133 Electric Motors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61134 Steam and Gas Turbines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61135 Compressors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61136 Reciprocating Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 6114 Advanced Fault Diagnostic Techniques
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 53191ch7
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • Chapter 7 Vibration-Based Tool Condition Monitoring Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 71 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 72 Mechanics of Turning
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 721 General Terms
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 722 Chatter Vibrations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 723 Tool Wear
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7231 Tool Failure Mechanisms
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7232 Tool Failure Modes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7233 Tool Wear Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7234 Tool Wear Stages
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 73 Vibration Signal Recording
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 731 Direct and Indirect Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 732 Sensor Requirements for Tool Wear Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 733 Force Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7331 Direct Measurement Dynamometers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7332 Indirect Force Sensors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7333 Piezoelectric Strain Sensors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7334 Resistance Strain Gauges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7335 Customized Force Sensors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 734 Acceleration Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 735 Acoustic Emission Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 736 Sensor Comparisons
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 74 Signal Processing for Sensor-Based Tool Condition Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 741 Feature Extraction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7411 Time Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7412 Frequency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7413 Statistical Processing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7414 TimendashFrequency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 742 Feature Selection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 75 Wear ModelDecision-Making for Sensor-Based Tool Condition Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 751 Trending Threshold
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 752 Neural Networks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7521 Unsupervised Networks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7522 Supervised Networks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 753 Fuzzy Logic
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 754 Other Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 76 Conclusion
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53191ch8
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Chapter 8 Fault Diagnosis of Helicopter Gearboxes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 81 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 82 Abnormality Scaling
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 83 The Structure-Based Connectionist Network
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 84 Sensor Location Selection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 841 Coverage Index
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 842 Overlap Index
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 843 Monitoring Effectiveness
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 85 A Case Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 851 Structural and Featural Influences
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 852 Evaluation of Influences
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 853 Fault Detection Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 854 Fault Diagnostic Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 8541 Faulty Subsystem Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 8542 Faulty Component Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 855 Sensor Location Evaluation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 856 Sensor Location Validation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 86 Conclusion
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 53191ch9
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Chapter 9 Vibration Suppression and Monitoring in Precision Motion Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 91 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 92 Mechanical Design to Minimize Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 921 Stability and Static Determinacy of Machine Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 922 Two-Dimensional Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 923 Three-Dimensional Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 93 Adaptive Notch Filter
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 931 Fast Fourier Transform
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 932 Simulation and Experiments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 94 Real-Time Vibration Analyzer
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 941 Learning Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 942 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 943 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 944 Experiments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 9441 Input Variables mdash the Evaluation Criteria
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 94411 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 94412 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 9442 Evaluation Rules
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 94421 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 94422 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 9443 Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 94431 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 94432 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 95 Practical Insights and Case Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 96 Conclusions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 53191ch10
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Chapter 10 Vibration and Shock Problems of Civil Engineering Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 101 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 102 Earthquake-Induced Vibration of Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1021 Seismicity and Ground Motions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1022 Influence of Local Site Conditions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1023 Response of Structures to Ground Motions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1024 Dynamic Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10241 Equations of Motion for Linear Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10242 Equations of Motion for Linear Multiple-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1025 Earthquake Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10251 Elastic Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10252 Smoothed Design Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10253 Ductility-Modified Response Spectrum Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1026 Design Philosophy and the Code Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10261 Performance-Based Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1027 Analysis Options for Earthquake Effects
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10271 Dynamic Time History Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10272 Response Spectrum Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 102721 Response Spectrum Analysis of Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 102722 Response Spectrum Analysis of Multi-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10273 Equivalent Static Analysis (Force-Based Approach)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10274 Displacement-Based Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1028 SoilndashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1029 Active and Passive Control Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 10210 Worked Examples
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 103 Dynamic Effects of Wind Loading on Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1031 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1032 Wind Speed
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1033 Design Structures for Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10331 Types of Wind Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10332 Design Criteria
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10333 Static Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1034 Along and Across-Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10341 Along-Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10342 Across-Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1035 Wind Tunnel Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1036 Comfort Criteria Human Response to Building Motion
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1037 Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1038 Comparison with Earthquake Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 104 Vibrations Due to Fluid ndashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1041 Added Mass and Inertial Coupling
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1042 Wave-Induced Vibration of Structure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 105 Blast Loading and Blast Effects on Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1051 Explosions and Blast Phenomenon
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1052 Explosive Air-Blast Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10521 Blast Wave Scaling Laws
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10522 Prediction of Blast Pressure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1053 Gas Explosion Loading and Effect of Internal Explosions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1054 Structural Response to Blast Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10541 Elastic Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10542 Elasto-Plastic Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1055 Material Behaviors at High Strain Rate
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10551 Dynamic Properties of Concrete under High Strain Rates
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10552 Dynamic Properties of Reinforcing Steel under High Strain Rates
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1056 Failure Modes of Blast-Loaded Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10561 Global Structural Behavior
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10562 Localized Structural Behavior
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10563 PressurendashImpulse ( PndashI ) Diagrams
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1057 Blast WavendashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1058 Effect of Ground Shocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10581 Loads from Air-Induced Ground Shock
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10582 Loads from Direct Ground Shock
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1059 Technical Design Manuals for Blast-Resistant Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 10510 Computer Programs for Blast and Shock Effects
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 106 Impact Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1061 Structural Impact between Two Bodies mdash Hard Impact and Soft Impact
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1062 Example mdash Aircraft Impact
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 107 Floor Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1071 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1072 Types of Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10721 Walking
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10722 Rhythmic Activities
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10723 Mechanical Equipment
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10724 Analysis Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1073 Natural Frequency of Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10731 Computing the Natural Frequency
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10732 Computing Deflection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10733 Damping
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10734 Resonance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1074 Vibration Caused by Walking
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10741 Minimum Natural Frequency
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1075 Design for Rhythmic Excitation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10751 Harmonics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10752 Minimum Natural Frequency
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1076 Example mdash Vibration Analysis of a Reinforced Concrete Floor
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 53191ch11
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Chapter 11 Seismic Base Isolation and Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 111 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1111 From Ductility Design to Base Isolation and Control Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1112 The Importance of Reducing Seismic Input and Response
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 112 Seismic Base Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1121 Historical Development of Base Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1122 Basic Principle
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1123 Issues in Seismic Base Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11231 Performance Criteria
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11232 Type of Structure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11233 Site Characteristics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11234 Retrofit Issues
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11235 Design of Building Services
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11236 Expected Life of Isolator
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1124 Seismic Isolation Devices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11241 Laminated Rubber Bearings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11242 Lead Rubber Bearing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11243 Friction-Based Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11244 Other Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1125 Design of Isolation Devices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11251 High-Damping Rubber Bearing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112511 Stability against Buckling
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112512 Stability against Roll Out
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11252 Lead Rubber Bearings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112521 Design of Lead Plug
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112522 Design of Laminated Rubber Bearing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11253 Design of Friction Pendulum System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1126 Verification of Properties of Isolation Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11261 Tests for Isolation Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 112611 System Characterization Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 112612 Prototype Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 112613 Quality Control Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11262 Uniform Building Code Recommendations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112621 Units Dependent on Loading Rates
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112622 Units Dependent on Bilateral Load
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112623 System Adequacy
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1127 Analysis of Base-Isolated Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11271 Modeling of a Superstructure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11272 Modeling of Isolation System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11273 Static Analysis Procedure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11274 Dynamic Analysis Procedure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 112741 Response Spectrum Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 112742 Time-History Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11275 Software for Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1128 Experimental Methods for Isolated Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1129 Implementation of Seismic Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11291 New Construction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112911 Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112912 Bridges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11292 Seismic Retrofit
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112921 Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112922 Bridges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11293 Other Implementations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 11210 Performance during Past Earthquakes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 112101 Performance of Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 112102 Performance of Bridges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 113 Seismic Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1131 Historical Development of Seismic Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1132 Basic Principles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11321 Passive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11322 Active Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11323 Semiactive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11324 Hybrid Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11325 Categorization of Basic Principles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1133 Important Issues in Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11331 SoilndashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11332 DevicendashStructure Interaction and Time Delay
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11333 Design Guidelines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1134 Vibration-Control Devices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11341 Passive Control Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113411 Metallic Yielding Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113412 Friction Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113413 Viscoelastic Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113414 Viscous Fluid Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113415 Tuned Mass Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11342 Active Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113421 Electromagnetic Actuator
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113422 Hydraulic Actuators
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11343 Semiactive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113431 Variable-Orifice Hydraulic Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113432 Controllable Fluid Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113433 Controllable Friction Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11344 Hybrid Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1135 Control Algorithm
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11351 Active Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11352 Semiactive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113521 Common Control Schemes for Controllable Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113522 Special Control Schemes for Controllable Damper
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1136 Experimental Performance Verification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11361 Shaking Table Tests of a Flexible Structural Model with TMD AMD and ATMD
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11362 Substructure Hybrid Test
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113621 Hybrid Tests Using Hydraulic Actuator
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113622 Hybrid Tests Using Shaking Table
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113623 Hybrid Tests Using Inertia-Force-Driven Loading System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1137 Implementations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11371 Semiactive Control of Full-Scale Structures Using Variable Joint Damper System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113711 Background of Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113712 Test System Set Up
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113713 Control Algorithm
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113714 Test Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11372 Application of Structural Control Technologies to Seismic Retrofit of a Cable-Stayed Bridge
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113721 Background of Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113722 Basic Concept of Seismic Retrofit
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113723 Modal Shape Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113724 Time-History Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113725 Soil ndash Structure Interaction Effect
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113726 Semiactive Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53191ch12
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Chapter 12 Seismic Random Vibration of Long-Span Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 121 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1211 Basic Concepts of Random Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12111 Stationary Random Process
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12112 Nonstationary Random Process
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1212 Three Methods for Structural Seismic Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12121 Response Spectrum Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12122 Time-History Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12123 Random Vibration Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 121231 Davenport Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 121232 Vanmarcke Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 12124 Comparisons of the Three Seismic-Analysis Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 122 Seismic Random-Excitation Fields
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1221 Power Spectral Density of Spatially Varying Ground Acceleration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1222 Several Coherence Models
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12221 FengndashHu Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12222 Harichandran ndashVanmarcke Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12223 LohndashYeh Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12224 OliveirandashHaondashPenzien Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12225 LucondashWong Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12226 QundashWangndashWang Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1223 Generation of Ground Acceleration Power Spectral Density Curves from Acceleration Response Spectrum Curves
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12231 Kaul Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12232 Iteration Scheme
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1224 Seismic Equations of Motion of Long-Span Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1225 Seismic Waves and Their Geometrical Expressions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 123 Pseudoexcitation Method for Structural Random Vibration Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1231 Structures Subjected to Stationary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12311 Single Stationary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12312 Multiple Stationary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1232 Structures Subjected to Nonstationary Random Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12321 Structures Subjected to Uniformly Modulated Evolutionary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 123211 Single Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 123212 Multiple Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12322 Structures Subjected to Nonuniformly Modulated Evolutionary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 123221 Single Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 123222 Multiple Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1233 Precise Integration Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12331 Precise Integration of Exponential Matrices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12332 Particular Solutions and Precise Integration Formulas for Various Forms of Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 123321 Linear Loading Form (HPD-L Form)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 123322 Sinusoidal Loading Form (HPD-S Form)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 123323 Exponentially Decaying Sinusoidal Loading Form (HPD-E Form)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 124 Long-Span Structures Subjected to Stationary Random Ground Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1241 The Solution of Equations of Motion Using the Pseudoexcitation Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1242 Numerical Comparisons with Other Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12421 Song-Hua-Jiang Suspension Bridge
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 124211 All Supports Move Uniformly
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 124212 Wave Passage Effect Is Taken into Account
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 124213 Wave-Passage Effect and Incoherence Effect Are Jointly Taken into Account
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 12422 San Joaquin Concrete Bridge
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 125 Long-Span Structures Subjected to Nonstationary Random Ground Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1251 Modulation Functions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1252 The Formulas for Nonstationary Multiexcitation Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1253 Expected Extreme Values of Nonstationary Random Processes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1254 Numerical Comparisons with the Corresponding Stationary Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 126 Conclusions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 53191ch13
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Chapter 13 Seismic Qualification of Equipment
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 131 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 132 Distribution Qualification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1321 Drive-Signal Generation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1322 Distribution Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1323 Test Procedures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 133 Seismic Qualification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1331 Stages of Seismic Qualification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1332 Test Preliminaries
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1333 Single-Frequency Testing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1334 Multifrequency Testing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1335 Generation of RRS Specifications
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 53191ch14
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                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Chapter 14 Human Response to Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 141 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 142 Vibration Excitations on Humans
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1421 Excitation Characteristics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 143 Human Response to Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1431 Vibration Perception
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1432 Frequency Weighting Curve
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1433 Iso-Perception Curves
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1434 Detection Threshold Curve
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 144 Regulation of Human Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1441 Acceptable Vibration Levels in Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1442 Whole-Body Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1443 HandndashArm Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
Page 14: Vibration Monitoring, Testing, and Instrumentationpreview.kingborn.net › 646000 › d1a74678d91943e5ba1d5e... · The MEMS Handbook, Second Edition MEMS: Introduction and Fundamentals

4 Mechanical aging of a product prior to carrying out a test program

5 Exploratory testing of a product to determine its dynamic characteristics such as resonances

mode shapes and even a complete dynamic model

6 Vibration monitoring for performance evaluation

7 Control and suppression of vibration

Figure 11 indicates a procedure typical of experimental vibration highlighting the essential

instrumentation Vibrations are generated in a device the test object in response to some excitation In

some experimental procedures primarily in vibration testing (see Figure 11) the excitation signal has

to be generated in a signal generator in accordance with some requirement (specification) and applied to

the object through an exciter after amplification and conditioning In some other situations primarily in

performance monitoring and vibration control the excitations are generated as an integral part of the

operating environment of the vibrating object and may originate either within the object (eg engine

excitations in an automobile) or in the environment with which the object interacts during operation

(eg road disturbances on an automobile) Sensors are needed to measure vibrations in the test object In

particular a control sensor is used to check whether the specified excitation is applied to the object

and one or more response sensors may be used to measure the resulting vibrations at key locations of

the object

The sensor signals have to be properly conditioned for example by filtering and amplification and

modified for example through modulation demodulation and analog-to-digital conversion prior to

recording analyzing and display The purpose of the controller is to guarantee that the excitation is

correctly applied to the test object If the signal from the control sensor deviates from the required

excitation the controller modifies the signal to the exciter so as to reduce this deviation Furthermore the

controller will stabilize or limit (compress) the vibrations in the object It follows that instruments in

experimental vibration may be generally classified into the following categories

1 Signal-generating devices

2 Vibration exciters

3 Sensors and transducers

4 Signal conditioningmodifying devices

5 Signal analysis devices

6 Control devices

7 Vibration recording and display devices

AnalogDigital

Interface

DigitalSignal

RecorderAnalyzerDisplay

FilterAmplifier

FilterAmplifier

SignalGenerator

and ExciterController

Reference (Required)Signal (Specification)

PowerAmplifier

MountingFixtures

TestObject

ResponseSensor

ControlSensor

Exciter

SwivelBase

FIGURE 11 Typical instrumentation in experimental vibration

Vibration Monitoring Testing and Instrumentation1-2

53191mdash522007mdash1201mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

Note that one instrument may perform the tasks

of more than one category listed here Also more

than one instrument may be needed to carry out

tasks in a single category In the following sections

we will provide some examples of the types of

vibration instrumentation giving characteristics

operating principles and important practical

considerations Also we will describe several

experiments which can be found in a typical

vibration laboratory

An experimental vibration system generally

consists of four main subsystems

1 Test object

2 Excitation system

3 Control system

4 Signal acquisition and modification system

These are schematically shown in Figure 12 Note that various components shown in Figure 11 may

be incorporated into one of these subsystems In particular component matching hardware and object

mounting fixtures may be considered interfacing devices that are introduced through the interaction

between the main subsystems as shown in Figure 12 Some important issues of vibration testing and

instrumentation are summarized in Box 11

12 Vibration Exciters

Vibration experimentation may require an external exciter to generate the necessary vibration This is the

case in controlled experiments such as product testing where a specified level of vibration is applied to the

test object and the resulting response is monitored A variety of vibration exciters are available with

different capabilities and principles of operation

Three basic types of vibration exciters (shakers) are widely used hydraulic shakers inertial shakers

and electromagnetic shakers The operation-capability ranges of typical exciters in these three categories

are summarized in Table 11 Stroke or maximum displacement is the largest displacement the exciter

is capable of imparting onto a test object whose weight is assumed to be within its design load limit

Maximum velocity and acceleration are similarly defined Maximum force is the largest force that could

be applied by the shaker to a test object of acceptable weight (one within the design load) The values

given in Table 11 should be interpreted with caution Maximum displacement is achieved only at very

low frequencies The achievement of maximum velocity corresponds to intermediate frequencies in the

operating frequency range of the shaker Maximum acceleration and force ratings are usually achieved at

high frequencies It is not feasible for example to operate a vibration exciter at its maximum

displacement and its maximum acceleration simultaneously

Consider a loaded exciter that is executing harmonic motion Its displacement is given by

x frac14 s sin vt eth11THORN

in which s is the displacement amplitude (or stroke) Corresponding velocity and acceleration are

_x frac14 sv cos vt eth12THORN

eurox frac14 2sv2sin vt eth13THORN

SignalModification

System

TestObject

ControlSystem

VibrationExciter (Shaker)

System

FIGURE 12 Interactions between major subsystems of

an experimental vibration system

Vibration Instrumentation 1-3

53191mdash522007mdash1201mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

If the velocity amplitude is denoted by v and the acceleration amplitude by a it follows from Equation

12 and Equation 13 thatv frac14 vs eth14THORN

and

a frac14 vv eth15THORN

Box 11

VIBRATION INSTRUMENTATION

Vibration Testing Applications for Products

Design and Development Production Screening and Quality Assessment Utilization and Qualification for Special Applications

Testing Instrumentation

Exciter (excites the test object) Controller (controls the exciter for accurate excitation) Sensors and Transducers (measure excitations and responses and provide excitation error

signals to controller) Signal Conditioning (converts signals to appropriate form) Recording and Display (perform processing storage and documentation)

Exciters

Shakers

1 Electrodynamic (high bandwidth moderate power complex and multifrequency

excitations)

2 Hydraulic (moderate to high bandwidth high power complex and multifrequency

excitations)

3 Inertial (low bandwidth low power single-frequency harmonic excitations)

TransientInitial Condition

1 Hammers (impulsive bump tests)

2 Cable Release (step excitations)

3 Drop (impulsive)

Signal Conditioning

Filters Amplifiers Amplifiers ModulatorsDemodulators ADCDAC

Sensors

Motion (displacement velocity acceleration) Force (strain torque)

Vibration Monitoring Testing and Instrumentation1-4

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copy 2007 by Taylor amp Francis Group LLC

TABLE 11 Typical Operation-Capability Ranges for Various Shaker Types

Shaker Type Typical Operational Capabilities

Frequency Maximum Displacement

(Stroke)

Maximum

Velocity

Maximum

Acceleration

Maximum

Force

Excitation

Waveform

Hydraulic

(electrohydraulic)

Low

(01ndash500 Hz)

High (20 in 50 cm) Intermediate

(50 insec

125 cmsec)

Intermediate

(20 g)

High (100000 lbf

450000 N)

Average flexibility (simple

to complex and random)

Inertial

(counter-rotating mass)

Intermediate

(2ndash50 Hz)

Low (1 in 25 cm) Intermediate

(50 insec

125 cmsec)

Intermediate

(20 g)

Intermediate

(1000 lbf 4500 N)

Sinusoidal only

Electromagnetic

(electrodynamic)

High

(2ndash10000 Hz)

Low (1 in 25 cm) Intermediate

(50 insec

125 cmsec)

High (100 g) Low to intermediate

(450 lbf 2000 N)

High flexibility and accuracy

(simple to complex and

random)

VibrationInstru

mentation

1-5

53191mdash522007mdash

1201mdashSENTHILKUMARmdash246494mdash

CRCndashpp1ndash112

copy 2007 by Taylor amp Francis Group LLC

An idealized performance curve of a shaker

has a constant displacementndashamplitude region a

constant velocityndashamplitude region and a con-

stant accelerationndashamplitude region for low

intermediate and high frequencies respectively

in the operating frequency range Such an ideal

performance curve is shown in Figure 13(a) on a

frequencyndashvelocity plane Logarithmic axes are

used In practice typical shaker performance

curves would be fairly smooth yet nonlinear

curves similar to those shown in Figure 13(b)

As the mass increases the performance curve

compresses Note that the acceleration limit of a

shaker depends on the mass of the test object

(load) Full load corresponds to the heaviest object

that could be tested The ldquono loadrdquo condition

corresponds to a shaker without a test object To

standardize the performance curves they are

usually defined at the rated load of the shaker A

performance curve in the frequencyndashvelocity

plane may be converted to a curve in the

frequencyndashacceleration plane simply by increasing

the slope of the curve by a unit magnitude (ie

20 dbdecade)

Several general observations can be made from

Equation 14 and Equation 15 In the constant-

peak displacement region of the performance

curve the peak velocity increases proportionally

with the excitation frequency and the peak

acceleration increases with the square of the excitation frequency In the constant-peak velocity region

the peak displacement varies inversely with the excitation frequency and the peak acceleration increases

proportionately In the constant-peak acceleration region the peak displacement varies inversely with the

square of the excitation frequency and the peak velocity varies inversely with the excitation frequency

This further explains why rated stroke maximum velocity and maximum acceleration values are not

simultaneously realized

121 Shaker Selection

Vibration testing is accomplished by applying a specified excitation to the test package using a shaker

apparatus and monitoring the response of the test object Test excitation may be represented by its

response spectrum The test requires that the response spectrum of the actual excitation known as the

test response spectrum (TRS) envelops the response spectrum specified for the particular test known as

the required response spectrum (RRS)

A major step in the planning of any vibration testing program is the selection of a proper shaker

(exciter) system for a given test package The three specifications that are of primary importance in

selecting a shaker are the force rating the power rating and the stroke (maximum displacement) rating

Force and power ratings are particularly useful in moderate to high frequency excitations and the stroke

rating is the determining factor for low frequency excitations In this section a procedure is given to

determine conservative estimates for these parameters in a specified test for a given test package

Frequency domain considerations are used here

Stroke

Limit M

ax

Acceleration

MaxVelocity

Peak

Vel

ocity

(cm

s)

01 1 10 100

FullLoad

NoLoad

Frequency (Hz)(a)

Peak

Vel

ocity

(cm

s)

100

10

1

100

10

1

01 1 10 100

FullLoad

NoLoad

Frequency (Hz)(b)

FIGURE 13 Performance curve of a vibration exciter

in the frequencyndashvelocity plane (log) (a) ideal (b)

typical

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copy 2007 by Taylor amp Francis Group LLC

1211 Force Rating

In the frequency domain the (complex) force at the exciter (shaker) head is given by

F frac14 mHethvTHORNasethvTHORN eth16THORNin which v is the excitation frequency variable m is the total mass of the test package including

mounting fixture and attachments asethvTHORN is the Fourier spectrum of the support-location (exciter head)

acceleration and H(v) is frequency response function that takes into account the flexibility and

damping effects (dynamics) of the test package apart from its inertia In the simplified case where the

test package can be represented by a simple oscillator of natural frequency vn and damping ratio by zt

this function becomes

HethvTHORN frac14 1thorn 2jztv=vn=12 ethv=vnTHORN2 thorn 2jztv=vn eth17THORNin which j frac14 ffiffiffiffi

21p

This approximation is adequate for most practical purposes The static weight of the

test object is not included in Equation 16 Most heavy-duty shakers which are typically hydraulic

have static load support systems such as pneumatic cushion arrangements that can exactly balance the

dead load The exciter provides only the dynamic force In cases where shaker directly supports the

gravity load in the vertical test configuration Equation 16 should be modified by adding a term to

represent this weight

A common practice in vibration test applications is to specify the excitation signal by its response

spectrum This is simply the peak response of a simple oscillator expressed as a function of its natural

frequency when its support location is excited by the specified signal Clearly the damping of the simple

oscillator is an added parameter in a response spectrum specification Typical damping ratios ethzrTHORN used inresponse spectra specifications are less than 01 (or 10) It follows that an approximate relationship

between the Fourier spectrum of the support acceleration and its response spectrum is

as frac14 2jzrarethvTHORN eth18THORNThe magnitude larethvTHORNl is the response spectrumEquation 18 substituted into Equation 16 gives

F frac14 mHethvTHORN2jzrarethvTHORN eth19THORNIn view of Equation 17 for test packages having low damping the peak value of H(v) is

approximately 1=eth2jztTHORN this should be used in computing the force rating if the test package has a

resonance within the frequency range of testing On the other hand if the test package is assumed to be

rigid then HethvTHORN oslash 1 A conservative estimate for the force rating is

Fmax frac14 methzr=ztTHORNlarethvTHORNlmax eth110THORNIt should be noted that larethvTHORNlmax is the peak value of the specified (required) response spectrum (RRS)

for acceleration

1212 Power Rating

The exciter head does not develop its maximum force when driven at maximum velocity Output power

is determined by using

p frac14 Refrac12FvsethvTHORN eth111THORNin which vsethvTHORN is the Fourier spectrum of the exciter velocity and Re [ ] denotes the real part of a complex

function Note that as frac14 jvvs Substituting Equation 16 and Equation 18 into Equation 111 gives

p frac14 eth4mz2r =vTHORNRefrac12jHethvTHORNa2r ethvTHORN eth112THORNIt follows that a conservative estimate for the power rating is

pmax frac14 2methz2r =ztTHORNfrac12larethvTHORNl2=v max eth113THORN

Vibration Instrumentation 1-7

53191mdash522007mdash1201mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

Representative segments of typical acceleration RRS curves have slope n as given by

a frac14 k1vn eth114THORN

It should be clear from Equation 113 that the maximum output power is given by

pmax frac14 k2v2n21 eth115THORN

This is an increasing function for n 1=2 and a decreasing function for n 1=2 It follows that the power

rating corresponds to the highest point of contact between the acceleration RRS curve and a line of slope

equal to 12 A similar relationship may be derived if velocity RRS curves (having slopes n2 1) are used

1213 Stroke Rating

From Equation 18 it should be clear that the Fourier spectrum xs of the exciter displacement time

history can be expressed as

xs frac14 2zrarethvTHORN=jv2 eth116THORNAn estimate for stroke rating is

xmax frac14 2zrfrac12larethvTHORNl=v2 max eth117THORNThis is of the form

xmax frac14 kvn22 eth118THORNIt follows that the stroke rating corresponds to the highest point of contact between the acceleration

RRS curve and a line of slope equal to two

Example 11

A test package of overall mass 100 kg is to be

subjected to dynamic excitation represented by the

acceleration RRS (at 5 damping) as shown in

Figure 14 The estimated damping of the test

package is 7 The test package is known to have a

resonance within the frequency range of the

specified test Determine the exciter specifications

for the test

Solution

From the development presented in the previous

section it is clear that the point F (or P) in

Figure 14 corresponds to the force and output

power ratings and the point S corresponds to

the stroke rating The co-ordinates of these

critical points are F P frac14 eth42 Hz 40 gTHORN and S frac14 eth08 Hz 075 gTHORN Equation 110 gives the force

rating as

Fmax frac14 100 pound eth005=007THORN pound 40 pound 981 N frac14 2803 N

Equation 113 gives the power rating as

pmax frac14 2 pound 100 pound eth0052=007THORN pound frac12eth40 pound 981THORN2=42 pound 2p watts frac14 417 W

Equation 117 gives the stroke rating as

xmax frac14 2 pound 005 pound frac12eth075 pound 98THORN=eth08 pound 2pTHORN2 m frac14 3 cm

Acc

eler

atio

n(g

)

Con

stan

t Dis

plac

emen

t

Constant Velo

city

Frequency (Hz)

S

FP

0101

10 10 100

10

10

FIGURE 14 Test excitation specified by an accelera-

tion RRS (5 damping)

Vibration Monitoring Testing and Instrumentation1-8

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copy 2007 by Taylor amp Francis Group LLC

1214 Hydraulic Shakers

A typical hydraulic shaker consists of a piston-cylinder arrangement (also called a ram) a servo-valve a

fluid pump and a driving electric motor Hydraulic fluid (oil) is pressurized (typical operating pressure

4000 psi) and pumped into the cylinder through a servo-valve by means of a pump that is driven by an

electric motor (typical power 150 hp) The flow (typical rate 100 galmin) that enters the cylinder is

controlled (modulated) by the servo-valve which in effect controls the resulting piston (ram) motion

A typical servo-valve consists of a two-stage spool valve which provides a pressure difference and a

controlled (modulated) flow to the piston which sets it in motion

The servo-valve itself is moved by means of a linear torque motor which is driven by the excitation-

input signal (electrical) A primary function of the servo-valve is to provide a stabilizing feedback to the

ram In this respect the servo-valve complements the main control system of the test setup The ram is

coupled to the shaker table by means of a link with some flexibility The cylinder frame is mounted on the

support foundation with swivel joints This allows for some angular and lateral misalignment which

might be caused primarily by test-object dynamics as the table moves

Two-degree-of-freedom (Two-DoF) testing requires two independent sets of actuators and three-DoF

testing requires three independent actuator sets Each independent actuator set can consist of several

actuators operated in parallel using the same pump and the same excitation-input signal to the torque

motors

If the test table is directly supported on the vertical actuators they must withstand the total dead

weight (ie the weight of the test table the test object the mounting fixtures and the instrumentation)

This is requirement is usually prevented by providing a pressurized air cushion in the gap between the

test table and the foundation walls Air should be pressurized so as to balance the total dead weight

exactly (typical required gage pressure 3 psi)

Figure 15(a) shows the basic components of a typical hydraulic shaker The corresponding

operational block diagram is shown in Figure 15(b) It is desirable to locate the actuators in a pit in the

test laboratory so that the test tabletop is flushed with the test laboratory floor under no-load conditions

This minimizes the effort required to place the test object on the test table Otherwise the test object has

to be lifted onto the test table with a forklift Also installation of an aircushion to support the system

dead weight is difficult under these circumstances of elevated mounting

Hydraulic actuators are most suitable for heavy load testing and are widely used in industrial and civil

engineering applications They canbeoperated at very low frequencies (almost direct current [DC]) aswell

as at intermediate frequencies (see Table 11) Large displacements (stroke) are possible at low frequencies

Hydraulic shakers have the advantage of providing high flexibility of operation during the test their

capabilities include variable-force and constant-force testing and wide-band random-input testing The

velocity and acceleration capabilities of hydraulic shakers are moderate Although any general excitation-

input motion (for example sine wave sine beat wide-band random) can be used in hydraulic shakers

faithful reproduction of these signals is virtually impossible at high frequencies because of distortion and

higher-order harmonics introduced by the high noise levels that are common in hydraulic systems This

is only a minor drawback in heavy-duty intermediate-frequency applications Dynamic interactions are

reduced through feedback control

1215 Inertial Shakers

In inertial shakers or ldquomechanical excitersrdquo the force that causes the shaker-table motion is generated by

inertia forces (accelerating masses) Counter-rotating-mass inertial shakers are typical in this category

To understand their principle of operation consider two equal masses rotating in opposite directions at

the same angular speed v and in the same circle of radius r (see Figure 16) This produces a resultant

force equal to 2mv2r cos vt in a fixed direction (the direction of symmetry of the two rotating arms)

Consequently a sinusoidal force with a frequency of v and an amplitude proportional to v2 is generated

This reaction force is applied to the shaker table

Figure 17 shows a sketch of a typical counter-rotating-mass inertial shaker It consists of two identical

rods rotating at the same speed in opposite directions Each rod has a series of slots in which to

Vibration Instrumentation 1-9

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copy 2007 by Taylor amp Francis Group LLC

place weights In this manner the magnitude of

the eccentric mass can be varied to achieve various

force capabilities The rods are driven by a

variable-speed electric motor through a gear

mechanism that usually provides several speed

ratios A speed ratio is selected depending on the

required test-frequency range The whole system is

symmetrically supported on a carriage that is

directly connected to the test table The test object

is mounted on the test table The preferred

mounting configuration is horizontal so that the

excitation force is applied to the test object in a

horizontal direction In this configuration there

are no variable gravity moments (weight pounddistance to center of gravity) acting on the drive

mechanism Figure 17 shows the vertical con-

figuration In dynamic testing of large structures

the carriage can be mounted directly on the

structure at a location where the excitation force

should be applied By incorporating two pairs of

counter-rotating masses it is possible to generate

test moments as well as test forces

FIGURE 15 A typical hydraulic shaker arrangement (a) schematic diagram (b) operational block diagram

m m

2mw2r cos wt

wtw w

wt

FIGURE 16 Principle of operation of a counter-

rotating-mass inertial shaker

Vibration Monitoring Testing and Instrumentation1-10

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copy 2007 by Taylor amp Francis Group LLC

Reaction-type shakers driven by inertia are widely used for the prototype testing of civil engineering

structures Their first application dates back to 1935 Inertial shakers are capable of producing

intermediate excitation forces The force generated is limited by the strength of the carriage frame The

frequency range of operation and the maximum velocity and acceleration capabilities are also

intermediate for inertial shakers whereas the maximum displacement capability is typically low A major

limitation of inertial shakers is that their excitation force is exclusively sinusoidal and that the force

amplitude is directly proportional to the square of the excitation frequency As a result complex and

random excitation testing constant-force testing (for example transmissibility tests and constant-force

sine-sweep tests) and flexibility to vary the force amplitude or the displacement amplitude during a test

are not generally feasible with this type of shakers Excitation frequency and amplitude can be varied

during testing however by incorporating a variable-speed drive for the motor The sinusoidal excitation

generated by inertial shakers is virtually undistorted which gives them an advantage over the other types

of shakers when used in sine-dwell and sine-sweep tests Small portable shakers with low-force capability

are available for use in on-site testing

1216 Electromagnetic Shakers

In electromagnetic shakers or ldquoelectrodynamic excitersrdquo the motion is generated using the principle of

operation of an electric motor Specifically the excitation force is produced when a variable excitation

signal (electrical) is passed through a moving coil placed in a magnetic field

The components of a commercial electromagnetic shaker are shown in Figure 18 A steady magnetic

field is generated by a stationary electromagnet that consists of field coils wound on a ferromagnetic base

that is rigidly attached to a protective shell structure The shaker head has a coil wound around it When

the excitation electrical signal is passed through this drive coil the shaker head which is supported on

flexure mounts will be set in motion The shaker head consists of the test table on which the test object

is mounted Shakers with interchangeable heads are available The choice of appropriate shaker head is

based on the geometry and mounting features of the test object The shaker head can be turned to

different angles by means of a swivel joint In this manner different directions of excitation (in biaxial

and triaxial testing) can be obtained

FIGURE 17 Sketch of a counter-rotating-mass inertial shaker

Vibration Instrumentation 1-11

53191mdash522007mdash1202mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

122 Dynamics of Electromagnetic Shakers

Consider a single axis electromagnetic shaker (Figure 18) with a test object having a single natural

frequency of importance within the test frequency range The dynamic interactions between the shaker

and the test object give rise to two significant natural frequencies (and correspondingly two significant

resonances) These appear as peaks in the frequency response curve of the test setup Furthermore the

natural frequency (resonance) of the test package alone causes a ldquotroughrdquo or depression (antiresonance)

in the frequency response curve of the overall test setup To explain this characteristic consider the

dynamic model shown in Figure 19 The following mechanical parameters are defined for

Figure 19(a) m k and b are the mass stiffness and equivalent viscous damping constant respectively

of the test package and me ke and be are the corresponding parameters of the exciter (shaker) Also in

the equivalent electrical circuit of the shaker head as shown in Figure 19(b) the following electrical

parameters are defined Re and Le are the resistance and (leakage) inductance and kb is the back

electromotive force (back emf) of the linear motor Assuming that the gravitational forces are supported

FIGURE 18 Schematic sectional view of a typical electromagnetic shaker manufactured by Bruel and Kjaer

Denmark

Vibration Monitoring Testing and Instrumentation1-12

53191mdash522007mdash1202mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

by the static deflections of the flexible elements and that the displacements are measured from the static

equilibrium position we have the following system equations

Test object meuroy frac14 2kethy2 yeTHORN2 beth_y2 _yeTHORN eth119THORNShaker head me euroye frac14 fe thorn kethy2 yeTHORN thorn beth_y2 _yeTHORN2 key 2 be _ye eth120THORN

Electrical Lediedt

thorn Reie thorn kb _ye frac14 vethtTHORN eth121THORN

The electromagnetic force fe generated in the shaker head is a result of the interaction of the magnetic

field generated by the current ie with coil of the moving shaker head and the constant magnetic field

(stator) in which the head coil is located Here we have

fe frac14 kbie eth122THORNNote that v(t) is the voltage signal that is applied by the amplifier to the shaker coil ye is the displacement

of the shaker head and y is the displacement response of the test package

It is assumed that kb has consistent electrical and mechanical units (Vmsec and NA) Usually

the electrical time constant of the shaker is quite small compared with the primarily mechanical

time constants of the shaker and the test package In such cases the Ledie=dt term in Equation 121 may

be neglected Consequently the equations from Equation 119 through Equation 122 may be

expressed in the Laplace (frequency) domain with the Laplace variable s taking the place of the derivative

d=dt as

ethms2 thorn bsthorn kTHORNy frac14 ethbsthorn kTHORNye eth123THORN

FIGURE 19 Dynamic models of an electromagnetic shaker and a flexible test package (a) mechanical model

(b) electrical model

Vibration Instrumentation 1-13

53191mdash522007mdash1202mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

frac12mes2 thorn ethbthorn beTHORNsthorn ethkthorn keTHORN ye frac14 ethbsthorn kTHORNy thorn kb

Rev2

k2bs

Reye eth124THORN

It follows that the transfer function of the shaker head motion with respect to the excitation voltage is

given by

yevfrac14 kb

Re

DethsTHORNDdethsTHORN eth125THORN

where DethsTHORN is the characteristic function of the primary dynamics of the test object

DethsTHORN frac14 ms2 thorn bsthorn k eth126THORN

and DdethsTHORN is the characteristic function of the primary dynamic interactions between the shaker and thetest object

DcethsTHORN frac14 mmes4 thorn frac12methbe thorn bthorn boTHORN thornmeb s

3 thorn frac12methke thorn kTHORN thornmekthorn bethbe thorn boTHORN s2thorn frac12bke thorn ethbe thorn boTHORNk sthorn kke

eth127THORN

where

bo frac14 k2bRe

eth128THORN

It is clear that under low damping conditions DdethsTHORN will produce two resonances as it is fourth order in sand similarly DethsTHORN will produce one antiresonance (trough) corresponding to the resonance of the testobject Note that in the frequency domain s frac14 jv and hence the frequency response function given by

Equation 125 is in fact

yevfrac14 kb

Rb

DethjvTHORNDdethjvTHORN eth129THORN

The magnitude of this frequency response function for a typical test system is sketched in Figure 110

Note that this curve is for the ldquoopen-looprdquo case where there is no feedback from the shaker controller

In practice the shaker controller will be able

to compensate for the resonances and anti-

resonances to some degree depending on its

effectiveness

The main advantages of electromagnetic

shakers are their high frequency range of

operation their high degree of operating flexi-

bility and the high level of accuracy of the

generated shaker motion Faithful reproduction

of complex excitations is possible because of the

advanced electronics and control systems used in

this type of shakers Electromagnetic shakers are

not suitable for heavy-duty applications (large test

objects) however High test-input accelerations

are possible at high frequencies when electromag-

netic shakers are used but their displacement and

velocity capabilities are limited to low or

intermediate values (see Table 11)

100

10

1 10 100Excitation Frequency (Hz)

Antiresonance

Resonance

Shak

erD

ispl

acem

entM

agni

tude

Resonance

1000

FIGURE 110 Frequency response curve of a typical

electromagnetic shaker with a test object

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1221 Transient Exciters

Other varieties of exciters are commonly used in

transient-type vibration testing In these tests

either an impulsive force or an initial excitation is

applied to the test object and the resulting

response is monitored The excitations and the

responses are ldquotransientrdquo in this case Hammer

test drop tests and pluck tests fall into this

category For example a hammer test may be

conducted by hitting the object with an instru-

mented hammer and then measuring the response

of the object The hammer has a force sensor at its

tip as sketched in Figure 111 A piezoelectric or

strain-gage type force sensor may be used More

sophisticated hammers have impedance heads in

place of force sensors An impedance head

measures force and acceleration simultaneously

The results of a hammer test will depend on many

factors for example the dynamics of the hammer

body how firmly the hammer is held during the

impact how quickly the impact is applied and

whether there are multiple impacts

13 Control System

The two primary functions of the shaker control system in vibration testing are (1) to guarantee that the

specified excitation is applied to the test object and (2) to ensure that the dynamic stability (motion

constraints) of the test setup is preserved An operational block diagram illustrating these control

functions is given in Figure 112 The reference input to the control system represents the desired

excitation force that should be applied to the test object In the absence of any control however the force

reaching the test object will be distorted primarily because of (1) dynamic interactions and

nonlinearities of the shaker the test table the mounting fixtures the auxiliary instruments and the test

object itself (2) noise and errors in the signal generator amplifiers filters and other equipment and (3)

external loads and disturbances acting on the test object and other components (for example external

restraints aerodynamic forces friction) To compensate for these distorting factors response

measurements (displacements velocities acceleration and so on) are made at various locations in the

test setup and are used to control the system dynamics In particular the responses of the shaker the test

table and the test object are measured These responses are used to compare the actual excitation felt by

FIGURE 111 An instrumented hammer used in bump

tests or hammer tests

ExcitationInput

(Reference)

Feedback Paths

DriveSignal

ShakerResponse

TestTable

TestObject

Test ObjectResponse

Test TableResponseExciter

(Shaker)(Ram)

Controllerand

Amplifier

FIGURE 112 Operational block diagram illustrating a general shaker control system

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copy 2007 by Taylor amp Francis Group LLC

the test object at the shaker interface with the desired (specified) input The drive signal to the shaker is

modified depending on the error that is present

Two types of control are commonly employed in shaker apparatus simple manual control and

complex automatic control Manual control normally consists of simple open-loop trial-and-error

methods of manual adjustments (or calibration) of the control equipment to obtain a desired dynamic

response The actual response is usually monitored (on an oscilloscope or frequency analyzer screen for

example) during manual-control operations The pretest adjustments in manual control can be very

time-consuming as a result the test object might be subjected to overtesting which could produce

cumulative damage is undesirable and could defeat the test purpose Furthermore the calibration

procedure for the experimental setup must be repeated for each new test object

The disadvantages ofmanual control suggest that automatic control is desirable in complex test schemes

in which high accuracy of testing is desired The first step of automatic control involves automatic

measurement of the system response using control sensors and transducers The measurement is then fed

back into the control system which instantaneously determines the best drive signal to actuate the shaker

in order to get the desired excitation This may be done by either analog or digital methods

Primitive control systems require an accurate mathematical description of the test object This

dependency of the control system on the knowledge of test-object dynamics is clearly undesirable

Performance of a good control system should not be considerably affected by the dynamic interactions

and nonlinearities of the test object or by the nature of the excitation Proper selection of feedback signals

and control-system components can reduce such effects and will make the system robust

In the response-spectrum method of vibration testing it is customary to use displacement control at

low frequencies velocity control at intermediate frequency and acceleration control at high frequencies

This necessitates feedback of displacement velocity and acceleration responses Generally however the

most important feedback is the velocity feedback In sine-sweep tests the shaker velocity must change

steadily over the frequency band of interest In particular the velocity control must be precise near the

resonances of the test object Velocity (speed) feedback has a stabilizing effect on the dynamics which is

desirable This effect is particularly useful in ensuring stability in motion when testing is done near

resonances of lightly damped test objects On the contrary displacement (position) feedback can have a

destabilizing effect on some systems particularly when high feedback gains are used

The controller usually consists of various instruments equipment and computation hardware and

software Often the functions of the data-acquisition and processing system overlap with those of the

controller to some extent As an example consider the digital-controller of vibration testing apparatus

First the responses are measured through sensors (and transducers) filtered and amplified

(conditioned) These data channels may be passed through a multiplexer whose purpose is to select

one data channel at a time for processing Most modern data acquisition hardware does not need a

separate multiplexer to handle multiple signals The analog data are converted into digital data using

analog-to-digital converters (ADCs) The resulting sampled data are stored on a disk or as a block data in

the computer memory The reference input signal (typically a signal recorded on an FM tape) is also

sampled (if it is not already in the digital form) using an ADC and fed into the computer Digital

processing is done on the reference signal and the response data with the objective of computing the

command signal to drive the shaker The digital command signal is converted into an analog signal using

a digital-to-analog converter (DAC) and amplified (conditioned) before it is used to drive the exciter

The nature of the control components depends to a large extent on the nature and objectives of the

particular test to be conducted Some of the basic components in a shaker controller are described in

the following subsections

131 Components of a Shaker Controller

1311 Compressor

A compressor circuit is incorporated in automatic excitation control devices to control the excitation-

input level automatically The level of control depends on the feedback signal from a control sensor and

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copy 2007 by Taylor amp Francis Group LLC

the specified (reference) excitation signal Usually the compressor circuit is included in the excitation-

signal generator (for example in a sine generator) The control by this means may be done on the basis of

a single-frequency component (eg the fundamental frequency)

1312 Equalizer (Spectrum Shaper)

Random-signal equalizers are used to shape the spectrum of a random signal in a desired manner In

essence and equalizer consists of a bank of narrow-band filters (for example 80 filters) in parallel over

the operating frequency range By passing the signal through each filter the spectral density (or the mean

square value) of the signal in that narrow frequency band (for example each one-third-octave band) is

determined This is compared with the desired spectral level and automatic adjustment is made in that

filter in case there is an error In some systems response-spectrum analysis is made in place of power

spectral density analysis In that case the equalizer consists of a bank of simple oscillators whose

resonant frequencies are distributed over the operating frequency range of the equalizer The feedback

signal is passed through each oscillator and the peak value of its output is determined This value is

compared with the desired response spectrum value at that frequency If there is an error automatic gain

adjustment is made in the appropriate excitation signal components

Random-noise equalizers are used in conjunction with random signal generators They receive

feedback signals from the control sensors In some digital control systems there are algorithms (software)

that are used to iteratively converge the spectrum of the excitation signal felt by the test object into the

desired spectrum

1313 Tracking Filter

Many vibration tests are based on single-frequency excitations In such cases the control functions

should be performed on the basis of the amplitudes of the fundamental-frequency component of the

signal A tracking filter is simply a frequency-tuned band-pass filter It automatically tunes the center

frequency of its very narrow-band-pass filter to the frequency of a carrier signal Then when a noisy

signal is passed through the tuned filter the output of the filter will be the required fundamental

frequency component in the signal Tracking filters also are useful in obtaining amplitudendashfrequency

plots using an XndashY plotter In such cases the frequency value comes from the signal generator (sweep

oscillator) which produces the carrier signal to the tracking filter The tracking filter then determines the

corresponding amplitude of a signal that is fed into it Most tracking filters have dual channels so that two

signals can be handled (tracked) simultaneously

1314 Excitation Controller (Amplitude Servo-Monitor)

An excitation controller is typically an integral part of the signal generator It can be set so that automatic

sweep between two frequency limits can be performed at a selected sweep rate (linear or logarithmic)

More advanced excitation controllers have the capability of an automatic switch-over between constant-

displacement constant-velocity and constant-acceleration excitation-input control at specified

frequencies over the sweep frequency interval Consequently integrator circuits should be present

within the excitation controller unit to determine velocities and displacements from acceleration signals

Sometimes integration is performed by a separate unit called a vibration meter This unit also offers

the operator the capability of selecting the desired level of each signal (acceleration velocity or

displacement) There is an automatic cut-off level for large displacement values that could result from

noise in acceleration signals A compressor is also a subcomponent of the excitation controller The

complete unit is sometimes known as an amplitude servo-monitor

132 Signal-Generating Equipment

Shakers are force-generating devices that are operated using drive (excitation) signals generated from a

source The excitation-signal source is known as the signal generator Three major types of signal

generators are used in vibration testing applications (1) oscillators (2) random-signal generators and

(3) storage devices In some units oscillators and random-signal generators are combined We shall

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copy 2007 by Taylor amp Francis Group LLC

discuss these two generators separately however because of their difference in function It also should be

noted that almost any digital signal (deterministic or random) can be generated by a digital computer

using a suitable computer program the signal eventually can be passed through a DAC to obtain

the corresponding analog signal These lsquodigitalrsquo signal generators along with analog sources such as

magnetic tape players (FM) are classified into the category of storage devices

The dynamic range of equipment is the ratio of the maximum and minimum output levels (expressed

in decibels) at which it is capable of operating without significant error This is an important specification

for many types of equipment particularly for signal-generating devices The output level of the signal

generator should be set to a value within its dynamic range

1321 Oscillators

Oscillators are essentially single-frequency generators Typically sine signals are generated but other

waveforms (such as rectangular and triangular pulses) are also available in most oscillators Normally

an oscillator has two modes of operation (1) sweeping up and down between two frequency limits and

(2) dwelling at a specified frequency In the sweep operation the sweep rate should be specified This can

be done either on a linear scale (Hzmin) or on a logarithmic scale (octavesmin) In the dwell operation

the frequency points (or intervals) should be specified In either case a desired signal level can be chosen

using the gain-control knob An oscillator that is operated exclusively in the sweep mode is called a sweep

oscillator

The early generation of oscillators employed variable inductor-capacitor types of electronic circuits to

generate signals oscillating at a desired frequency The oscillator is tuned to the required frequency by

varying the capacitance or inductance parameters A DC voltage is applied to energize the capacitor

and to obtain the desired oscillating voltage signal which subsequently is amplified and conditioned

Modern oscillators use operational amplifier circuits along with resistor capacitor and semiconductor

(SC) elements Also common are crystal (quartz) parallel-resonance oscillators used to generate voltage

signals accurately at a fixed frequency The circuit is activated using a DC-voltage source Other

frequencies of interest are obtained by passing this high-frequency signal through a frequency converter

The signal is then conditioned (amplified and filtered) Required shaping (for example rectangular

pulse) is obtained using a shape circuit Finally the required signal level is obtained by passing the

resulting signal through a variable-gain amplifier A block diagram of an oscillator illustrating various

stages in the generation of a periodic signal is given in Figure 113

A typical oscillator offers a choice of several (typically six) linear and logarithmic frequency ranges and

a sizable level of control capability (for example 80 dB) Upper and lower frequency limits in a sweep can

be preset on the front panel to any of the available frequency ranges Sweep-rate settings are continuously

DC Voltage

Oscillator

FrequencySpecification

FrequencyConverter

FilterAmplifier

ShaperPeriodicSignal

FrequencyCounter

Fixed-FrequencySignal

Variable-GainOutput

Amplifier

SignalSpecification

LevelSpecification

FIGURE 113 Block diagram of an oscillator-type signal generator

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copy 2007 by Taylor amp Francis Group LLC

  • 53191fm
    • Vibration Monitoring Testing and Instrumentation
      • Preface
      • Acknowledgments
      • Editor-in-Chief
      • Contributors
      • Contents
      • Related Titles
          • 53191ch1
            • Table of Contents
            • Chapter 1 Vibration Instrumentation
              • Summary
              • 11 Introduction
              • 12 Vibration Exciters
                • 121 Shaker Selection
                  • 1211 Force Rating
                  • 1212 Power Rating
                  • 1213 Stroke Rating
                  • 1214 Hydraulic Shakers
                  • 1215 Inertial Shakers
                  • 1216 Electromagnetic Shakers
                    • 122 Dynamics of Electromagnetic Shakers
                      • 1221 Transient Exciters
                          • 13 Control System
                            • 131 Components of a Shaker Controller
                              • 1311 Compressor
                              • 1312 Equalizer (Spectrum Shaper)
                              • 1313 Tracking Filter
                              • 1314 Excitation Controller (Amplitude Servo-Monitor)
                                • 132 Signal-Generating Equipment
                                  • 1321 Oscillators
                                  • 1322 Random Signal Generators
                                  • 1323 Tape Players
                                  • 1324 Data Processing
                                      • 14 Performance Specification
                                        • 141 Parameters for Performance Specification
                                          • 1411 Time-Domain Specifications
                                          • 1412 Frequency-Domain Specifications
                                            • 142 Linearity
                                            • 143 Instrument Ratings
                                              • 1431 Rating Parameters
                                                • 144 Accuracy and Precision
                                                  • 15 Motion Sensors and Transducers
                                                    • 151 Potentiometer
                                                      • 1511 Potentiometer Resolution
                                                      • 1512 Optical Potentiometer
                                                        • 152 Variable-Inductance Transducers
                                                          • 1521 Mutual-Induction Transducers
                                                          • 1522 Linear-Variable Differential Transformer
                                                          • 1523 Signal Conditioning
                                                            • 153 Mutual-Induction Proximity Sensor
                                                            • 154 Selfinduction Transducers
                                                            • 155 Permanent-Magnet Transducers
                                                            • 156 Alternating Current Permanent-Magnet Tachometer
                                                            • 157 Alternating Current Induction Tachometer
                                                            • 158 Eddy Current Transducers
                                                            • 159 Variable-Capacitance Transducers
                                                              • 1591 Capacitive Displacement Sensors
                                                              • 1592 Capacitive Angular Velocity Sensor
                                                              • 1593 Capacitance Bridge Circuit
                                                                • 1510 Piezoelectric Transducers
                                                                  • 15101 Sensitivity
                                                                  • 15102 Piezoelectric Accelerometer
                                                                  • 15103 Charge Amplifier
                                                                      • 16 Torque Force and Other Sensors
                                                                        • 161 Strain Gage Sensors
                                                                          • 1611 Equations for Strain Gage Measurements
                                                                          • 1612 Bridge Sensitivity
                                                                          • 1613 The Bridge Constant
                                                                          • 1614 The Calibration Constant
                                                                          • 1615 Data Acquisition
                                                                          • 1616 Accuracy Considerations
                                                                          • 1617 Semiconductor Strain Gages
                                                                          • 1618 Force and Torque Sensors
                                                                          • 1619 Strain Gage Torque Sensors
                                                                          • 16110 Deflection Torque Sensors
                                                                          • 16111 Variable-Reluctance Torque Sensor
                                                                          • 16112 Reaction Torque Sensors
                                                                            • 162 Miscellaneous Sensors
                                                                              • 1621 Stroboscope
                                                                              • 1622 Fiber Optic Sensors and Lasers
                                                                              • 1623 Fiber-Optic Gyroscope
                                                                              • 1624 Laser Doppler Interferometer
                                                                              • 1625 Ultrasonic Sensors
                                                                              • 1626 Gyroscopic Sensors
                                                                                  • References
                                                                                  • Appendix 1A Virtual Instrumentation for Data Acquisition Analysis and Presentation
                                                                                    • Summary
                                                                                    • List of Abbreviations
                                                                                    • 1A1 Dynamic Signals
                                                                                      • 1A11 Acquiring and Simulating Dynamic Signals
                                                                                        • 1A111 Aliasing
                                                                                        • 1A112 Time Continuity
                                                                                            • 1A2 Measurement Configuration Considerations
                                                                                              • 1A21 Input Signal Considerations
                                                                                                • 1A211 Input Pseudodifferential and Differential Configuration
                                                                                                • 1A212 Gain
                                                                                                • 1A213 Input Coupling
                                                                                                • 1A214 Integrated Electronic Piezoelectric Excitation
                                                                                                • 1A215 Nyquist Frequency and Bandwidth
                                                                                                • 1A216 Analog-to-Digital Conversion
                                                                                                • 1A217 Antialias Filters
                                                                                                • 1A218 Input Filter Delay
                                                                                                • 1A219 Overload Detection
                                                                                                  • 1A22 Output Signal Considerations
                                                                                                    • 1A221 Output Pseudodifferential and Differential Configuration
                                                                                                    • 1A222 Attenuation
                                                                                                    • 1A223 Digital-to-Analog Conversion
                                                                                                    • 1A224 Anti-imaging and Interpolation Filters
                                                                                                    • 1A225 Output Filter Delay
                                                                                                        • 1A3 Scaling and Calibration
                                                                                                          • 1A31 Scaling to Engineering Units
                                                                                                          • 1A32 Performing System Calibration
                                                                                                            • 1A321 Propagation Delay Calibration
                                                                                                                • 1A4 Limit Testing Analysis
                                                                                                                  • 1A41 Limit Testing Overview
                                                                                                                  • 1A42 Using the SVT Limit Testing VI
                                                                                                                    • 1A5 Integration
                                                                                                                      • 1A51 Introduction to Integration
                                                                                                                      • 1A52 Implementing Integration
                                                                                                                        • 1A521 Challenges when Integrating Vibration Data
                                                                                                                          • 1A53 Time-Domain Integration
                                                                                                                            • 1A531 Single-Shot Acquisition and Integration
                                                                                                                            • 1A532 Continuous Acquisition and Integration
                                                                                                                              • 1A54 Frequency-Domain Integration
                                                                                                                                • 1A6 Vibration-Level Measurements
                                                                                                                                  • 1A61 Measuring the Root Mean Square Level
                                                                                                                                    • 1A611 Single-Shot Buffered Acquisition
                                                                                                                                    • 1A612 Continuous Signal Acquisition
                                                                                                                                      • 1A62 Performing a Running RMS Level Measurement
                                                                                                                                      • 1A63 Computing the Peak Level
                                                                                                                                      • 1A64 Computing the Crest Factor
                                                                                                                                        • 1A7 Frequency Analysis
                                                                                                                                          • 1A71 FFT Fundamentals
                                                                                                                                            • 1A711 Number of Samples
                                                                                                                                            • 1A712 Frequency Resolution
                                                                                                                                            • 1A713 Maximum Resolvable Frequency
                                                                                                                                            • 1A714 Minimum Resolvable Frequency
                                                                                                                                            • 1A715 Number of Spectral Lines
                                                                                                                                            • 1A716 Relationship between Time-Domain and Frequency-Domain Specifications and Parameters
                                                                                                                                              • 1A72 Increasing Frequency Resolution
                                                                                                                                                • 1A721 Zoom FFT Analysis
                                                                                                                                                • 1A722 Frequency Resolution of the Zoom FFT VIs
                                                                                                                                                • 1A723 Zoom Measurement
                                                                                                                                                • 1A724 Zoom Settings
                                                                                                                                                • 1A725 Subset Analysis
                                                                                                                                                    • 1A8 Transient Analysis
                                                                                                                                                      • 1A81 Transient Analysis with the Sound and Vibration Toolkit
                                                                                                                                                      • 1A82 Performing an STFT vs Time
                                                                                                                                                        • 1A821 Selecting the FFT Block Size
                                                                                                                                                        • 1A822 Overlapping
                                                                                                                                                        • 1A823 Using the SVT STFT vs Time VI
                                                                                                                                                          • 1A83 Performing an STFT vs Rotational Speed
                                                                                                                                                            • 1A831 Converting the Pulse Train to Rotational Speed
                                                                                                                                                            • 1A832 STFT vs RPM
                                                                                                                                                              • 1A84 Measuring a Shock Response Spectrum
                                                                                                                                                                • 1A9 Waterfall Display
                                                                                                                                                                  • 1A91 Using the Display VIs
                                                                                                                                                                    • 1A911 Initializing the Display
                                                                                                                                                                    • 1A912 Sending Data to the Display
                                                                                                                                                                    • 1A913 Waterfall Display for Frequency Analysis
                                                                                                                                                                    • 1A914 Waterfall Display for Transient Analysis
                                                                                                                                                                    • 1A915 Waterfall Display for Octave Spectra
                                                                                                                                                                        • 1A10 Swept-Sine Measurements
                                                                                                                                                                          • 1A101 Swept-Sine Overview
                                                                                                                                                                          • 1A102 Choosing Swept-Sine vs FFT Measurements
                                                                                                                                                                          • 1A103 Taking a Swept-Sine Measurement
                                                                                                                                                                          • 1A104 Swept-Sine Measurement Example
                                                                                                                                                                              • Bibliography
                                                                                                                                                                              • Related Titles
                                                                                                                                                                                  • 53191ch2
                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                    • Chapter 2 Signal Conditioning and Modification
                                                                                                                                                                                      • Summary
                                                                                                                                                                                      • 21 Introduction
                                                                                                                                                                                      • 22 Amplifiers
                                                                                                                                                                                        • 221 Operational Amplifier
                                                                                                                                                                                        • 222 Use of Feedback in Opamp
                                                                                                                                                                                        • 223 Voltage Current and Power Amplifiers
                                                                                                                                                                                          • 2231 Charge Amplifiers
                                                                                                                                                                                            • 224 Instrumentation Amplifiers
                                                                                                                                                                                              • 2241 Differential Amplifier
                                                                                                                                                                                              • 2242 Common Mode
                                                                                                                                                                                                • 225 Amplifier Performance Ratings
                                                                                                                                                                                                  • 2251 Common-Mode Rejection Ratio
                                                                                                                                                                                                    • 226 Component Interconnection
                                                                                                                                                                                                      • 2261 Impedance Characteristics
                                                                                                                                                                                                      • 2262 Cascade Connection of Devices
                                                                                                                                                                                                      • 2263 AC-Coupled Ampliers
                                                                                                                                                                                                          • 23 Analog Filters
                                                                                                                                                                                                            • 231 Passive Filters and Active Filters
                                                                                                                                                                                                              • 2311 Number of Poles
                                                                                                                                                                                                                • 232 Low-Pass Filters
                                                                                                                                                                                                                  • 2321 Low-Pass Butterworth Filter
                                                                                                                                                                                                                    • 233 High-Pass Filters
                                                                                                                                                                                                                    • 234 Band-Pass Filters
                                                                                                                                                                                                                      • 2341 Resonance-Type Band-Pass Filters
                                                                                                                                                                                                                        • 235 Band-Reject Filters
                                                                                                                                                                                                                          • 24 Modulators and Demodulators
                                                                                                                                                                                                                            • 241 Amplitude Modulation
                                                                                                                                                                                                                              • 2411 Modulation Theorem
                                                                                                                                                                                                                              • 2412 Side Frequencies and Side Bands
                                                                                                                                                                                                                                • 242 Application of Amplitude Modulation
                                                                                                                                                                                                                                  • 2421 Fault Detection and Diagnosis
                                                                                                                                                                                                                                    • 243 Demodulation
                                                                                                                                                                                                                                      • 25 Analog ndashDigital Conversion
                                                                                                                                                                                                                                        • 251 Digital-to-Analog Conversion
                                                                                                                                                                                                                                          • 2511 DAC Error Sources
                                                                                                                                                                                                                                            • 252 Analog-to-Digital Conversion
                                                                                                                                                                                                                                            • 253 Analog-to-Digital Converter Performance Characteristics
                                                                                                                                                                                                                                              • 2531 Resolution and Quantization Error
                                                                                                                                                                                                                                              • 2532 Monotonicity Nonlinearity and Offset Error
                                                                                                                                                                                                                                              • 2533 Analog-to-Digital Converter Conversion Rate
                                                                                                                                                                                                                                                • 254 Sample-and-Hold Circuitry
                                                                                                                                                                                                                                                • 255 Digital Filters
                                                                                                                                                                                                                                                  • 2551 Software Implementation and Hardware Implementation
                                                                                                                                                                                                                                                      • 26 Bridge Circuits
                                                                                                                                                                                                                                                        • 261 Wheatstone Bridge
                                                                                                                                                                                                                                                        • 262 Constant-Current Bridge
                                                                                                                                                                                                                                                        • 263 Bridge Amplifiers
                                                                                                                                                                                                                                                          • 2631 Half-Bridge Circuits
                                                                                                                                                                                                                                                            • 264 Impedance Bridges
                                                                                                                                                                                                                                                              • 2641 Owen Bridge
                                                                                                                                                                                                                                                              • 2642 Wien-Bridge Oscillator
                                                                                                                                                                                                                                                                  • 27 Linearizing Devices
                                                                                                                                                                                                                                                                    • 271 Linearization by Software
                                                                                                                                                                                                                                                                    • 272 Linearization by Hardware Logic
                                                                                                                                                                                                                                                                    • 273 Analog Linearizing Circuitry
                                                                                                                                                                                                                                                                    • 274 Offsetting Circuitry
                                                                                                                                                                                                                                                                    • 275 Proportional-Output Circuitry
                                                                                                                                                                                                                                                                      • 2751 Curve-Shaping Circuitry
                                                                                                                                                                                                                                                                          • 28 Miscellaneous Signal Modification Circuitry
                                                                                                                                                                                                                                                                            • 281 Phase Shifters
                                                                                                                                                                                                                                                                            • 282 Voltage-to-Frequency Converter
                                                                                                                                                                                                                                                                            • 283 Frequency-to-Voltage Converter
                                                                                                                                                                                                                                                                            • 284 Voltage-to-Current Converters
                                                                                                                                                                                                                                                                            • 285 Peak-Hold Circuits
                                                                                                                                                                                                                                                                              • 29 Signal Analyzers and Display Devices
                                                                                                                                                                                                                                                                                • 291 Signal Analyzers
                                                                                                                                                                                                                                                                                • 292 Oscilloscopes
                                                                                                                                                                                                                                                                                  • 2921 Triggering
                                                                                                                                                                                                                                                                                  • 2922 Lissajous Patterns
                                                                                                                                                                                                                                                                                  • 2923 Digital Oscilloscopes
                                                                                                                                                                                                                                                                                      • Bibliography
                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                          • 53191ch3
                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                            • Chapter 3 Vibration Testing
                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                              • 31 Introduction
                                                                                                                                                                                                                                                                                              • 32 Representation of a Vibration Environment
                                                                                                                                                                                                                                                                                                • 321 Test Signals
                                                                                                                                                                                                                                                                                                  • 3211 Stochastic vs Deterministic Signals
                                                                                                                                                                                                                                                                                                    • 322 Deterministic Signal Representation
                                                                                                                                                                                                                                                                                                      • 3221 Single-Frequency Signals
                                                                                                                                                                                                                                                                                                      • 3222 Sine Sweep
                                                                                                                                                                                                                                                                                                      • 3223 Sine Dwell
                                                                                                                                                                                                                                                                                                      • 3224 Decaying Sine
                                                                                                                                                                                                                                                                                                      • 3225 Sine Beat
                                                                                                                                                                                                                                                                                                      • 3226 Sine Beat with Pauses
                                                                                                                                                                                                                                                                                                      • 3227 Multifrequency Signals
                                                                                                                                                                                                                                                                                                      • 3228 Actual Excitation Records
                                                                                                                                                                                                                                                                                                      • 3229 Simulated Excitation Signals
                                                                                                                                                                                                                                                                                                        • 323 Stochastic Signal Representation
                                                                                                                                                                                                                                                                                                          • 3231 Ergodic Random Signals
                                                                                                                                                                                                                                                                                                          • 3232 Stationary Random Signals
                                                                                                                                                                                                                                                                                                          • 3233 Independent and Uncorrelated Signals
                                                                                                                                                                                                                                                                                                          • 3234 Transmission of Random Excitations
                                                                                                                                                                                                                                                                                                            • 324 Frequency-Domain Representations
                                                                                                                                                                                                                                                                                                              • 3241 Fourier Spectrum Method
                                                                                                                                                                                                                                                                                                              • 3242 Power Spectral Density Method
                                                                                                                                                                                                                                                                                                                • 325 Response Spectrum
                                                                                                                                                                                                                                                                                                                  • 3251 Displacement Velocity and Acceleration Spectra
                                                                                                                                                                                                                                                                                                                  • 3252 Response-Spectra Plotting Paper
                                                                                                                                                                                                                                                                                                                  • 3253 Zero-Period Acceleration
                                                                                                                                                                                                                                                                                                                  • 3254 Uses of Response Spectra
                                                                                                                                                                                                                                                                                                                    • 326 Comparison of Various Representations
                                                                                                                                                                                                                                                                                                                      • 33 Pretest Procedures
                                                                                                                                                                                                                                                                                                                        • 331 Purpose of Testing
                                                                                                                                                                                                                                                                                                                        • 332 Service Functions
                                                                                                                                                                                                                                                                                                                          • 3321 Active Equipment
                                                                                                                                                                                                                                                                                                                          • 3322 Passive Equipment
                                                                                                                                                                                                                                                                                                                          • 3323 Functional Testing
                                                                                                                                                                                                                                                                                                                            • 333 Information Acquisition
                                                                                                                                                                                                                                                                                                                              • 3331 Interface Details
                                                                                                                                                                                                                                                                                                                              • 3332 Effect of Neglecting Interface Dynamics
                                                                                                                                                                                                                                                                                                                              • 3333 Effects of Damping
                                                                                                                                                                                                                                                                                                                              • 3334 Effects of Inertia
                                                                                                                                                                                                                                                                                                                              • 3335 Effect of Natural Frequency
                                                                                                                                                                                                                                                                                                                              • 3336 Effect of Excitation Frequency
                                                                                                                                                                                                                                                                                                                              • 3337 Other Effects of Interface
                                                                                                                                                                                                                                                                                                                                • 334 Test-Program Planning
                                                                                                                                                                                                                                                                                                                                  • 3341 Testing of Cabinet-Mounted Equipment
                                                                                                                                                                                                                                                                                                                                    • 335 Pretest Inspection
                                                                                                                                                                                                                                                                                                                                      • 34 Testing Procedures
                                                                                                                                                                                                                                                                                                                                        • 341 Resonance Search
                                                                                                                                                                                                                                                                                                                                        • 342 Methods of Determining Frequency-Response Functions
                                                                                                                                                                                                                                                                                                                                          • 3421 Fourier Transform Method
                                                                                                                                                                                                                                                                                                                                          • 3422 Spectral Density Method
                                                                                                                                                                                                                                                                                                                                          • 3423 Harmonic Excitation Method
                                                                                                                                                                                                                                                                                                                                            • 343 Resonance-Search Test Methods
                                                                                                                                                                                                                                                                                                                                              • 3431 Hammer (Bump) Test and Drop Test
                                                                                                                                                                                                                                                                                                                                              • 3432 Pluck Test
                                                                                                                                                                                                                                                                                                                                              • 3433 Shaker Tests
                                                                                                                                                                                                                                                                                                                                                • 344 Mechanical Aging
                                                                                                                                                                                                                                                                                                                                                  • 3441 Equivalence for Mechanical Aging
                                                                                                                                                                                                                                                                                                                                                  • 3442 Excitation-Intensity Equivalence
                                                                                                                                                                                                                                                                                                                                                  • 3443 Dynamic-Excitation Equivalence
                                                                                                                                                                                                                                                                                                                                                  • 3444 Cumulative Damage Theory
                                                                                                                                                                                                                                                                                                                                                    • 345 Test-Response Spectrum Generation
                                                                                                                                                                                                                                                                                                                                                    • 346 Instrument Calibration
                                                                                                                                                                                                                                                                                                                                                    • 347 Test-Object Mounting
                                                                                                                                                                                                                                                                                                                                                    • 348 Test-Input Considerations
                                                                                                                                                                                                                                                                                                                                                      • 3481 Test Nomenclature
                                                                                                                                                                                                                                                                                                                                                      • 3482 Testing with Uncorrelated Excitations
                                                                                                                                                                                                                                                                                                                                                      • 3483 Symmetrical Rectilinear Testing
                                                                                                                                                                                                                                                                                                                                                      • 3484 Geometry vs Dynamics
                                                                                                                                                                                                                                                                                                                                                      • 3485 Some Limitations
                                                                                                                                                                                                                                                                                                                                                      • 3486 Testing Black Boxes
                                                                                                                                                                                                                                                                                                                                                      • 3487 Phasing of Excitations
                                                                                                                                                                                                                                                                                                                                                      • 3488 Testing a Gray or White Box
                                                                                                                                                                                                                                                                                                                                                      • 3489 Overtesting in Multitest Sequences
                                                                                                                                                                                                                                                                                                                                                          • 35 Some Practical Information
                                                                                                                                                                                                                                                                                                                                                            • 351 Random Vibration Test Example
                                                                                                                                                                                                                                                                                                                                                            • 352 Vibration Shakers and Control Systems
                                                                                                                                                                                                                                                                                                                                                              • Bibliography
                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                  • 53191ch4
                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                    • Chapter 4 Experimental Modal Analysis
                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                      • 41 Introduction
                                                                                                                                                                                                                                                                                                                                                                      • 42 Frequency-Domain Formulation
                                                                                                                                                                                                                                                                                                                                                                        • 421 Transfer-Function Matrix
                                                                                                                                                                                                                                                                                                                                                                        • 422 Principle of Reciprocity
                                                                                                                                                                                                                                                                                                                                                                          • 43 Experimental Model Development
                                                                                                                                                                                                                                                                                                                                                                            • 431 Extraction of the Time-Domain Model
                                                                                                                                                                                                                                                                                                                                                                              • 44 Curve Fitting of Transfer Functions
                                                                                                                                                                                                                                                                                                                                                                                • 441 Problem Identification
                                                                                                                                                                                                                                                                                                                                                                                • 442 Single- and Multi-Degree-of-Freedom Techniques
                                                                                                                                                                                                                                                                                                                                                                                • 443 Single-Degree-of-Freedom Parameter Extraction in the Frequency Domain
                                                                                                                                                                                                                                                                                                                                                                                  • 4431 Circle-Fit Method
                                                                                                                                                                                                                                                                                                                                                                                    • Case of Viscous Damping
                                                                                                                                                                                                                                                                                                                                                                                    • Case of Hysteretic Damping
                                                                                                                                                                                                                                                                                                                                                                                      • 4432 Peak-Picking Method
                                                                                                                                                                                                                                                                                                                                                                                        • 444 Multi-Degree of Freedom Curve Fitting
                                                                                                                                                                                                                                                                                                                                                                                          • 4441 Formulation of the Method
                                                                                                                                                                                                                                                                                                                                                                                            • 445 A Comment on Static Modes and Rigid-Body Modes
                                                                                                                                                                                                                                                                                                                                                                                            • 446 Residue Extraction
                                                                                                                                                                                                                                                                                                                                                                                              • 45 Laboratory Experiments
                                                                                                                                                                                                                                                                                                                                                                                                • 451 Lumped-Parameter System
                                                                                                                                                                                                                                                                                                                                                                                                  • 4511 Frequency-Domain Test
                                                                                                                                                                                                                                                                                                                                                                                                  • 4512 Time-Domain Tests
                                                                                                                                                                                                                                                                                                                                                                                                    • 452 Distributed-Parameter System
                                                                                                                                                                                                                                                                                                                                                                                                      • 46 Commercial EMA Systems
                                                                                                                                                                                                                                                                                                                                                                                                        • 461 System Configuration
                                                                                                                                                                                                                                                                                                                                                                                                          • 4611 FFT Analysis Options
                                                                                                                                                                                                                                                                                                                                                                                                          • 4612 Modal Analysis Components
                                                                                                                                                                                                                                                                                                                                                                                                              • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                  • 53191ch5
                                                                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                    • Chapter 5 Mechanical Shock
                                                                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                      • 51 Definitions
                                                                                                                                                                                                                                                                                                                                                                                                                        • 511 Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 512 Simple (or Perfect) Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 513 Half-Sine Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 514 Versed-Sine (or Haversine) Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 515 Terminal Peak Sawtooth Shock or Final Peak Sawtooth Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 516 Rectangular Shock
                                                                                                                                                                                                                                                                                                                                                                                                                          • 5161 Trapezoidal Shock
                                                                                                                                                                                                                                                                                                                                                                                                                              • 52 Description in the Time Domain
                                                                                                                                                                                                                                                                                                                                                                                                                              • 53 Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                • 531 Need
                                                                                                                                                                                                                                                                                                                                                                                                                                • 532 Shock Response Spectrum Definition
                                                                                                                                                                                                                                                                                                                                                                                                                                • 533 Response of a Linear One-Degree-of-Freedom System
                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5331 Shock Defined by a Force
                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5332 Shock Defined by an Acceleration
                                                                                                                                                                                                                                                                                                                                                                                                                                    • 534 Definitions
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5341 Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5342 Absolute Acceleration Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5343 Relative Displacement Shock Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5344 Primary Positive Shock Response Spectrum or Initial Positive Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5345 Primary (or Initial) Negative Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5346 Secondary (or Residual) Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5347 Positive (or Maximum Positive) Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5348 Negative (or Maximum Negative) Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5349 Maximax Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53410 Choice of Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                        • 535 Standardized Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5351 Definition
                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5352 Standardized Shock Response Spectra of Simple Shocks
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53521 Half-Sine Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53522 Versed Sine Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53523 Terminal Peak Sawtooth Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53524 Rectangular Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53525 Trapezoidal Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 536 Choice of Damping
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 537 Shock Response Spectra Domains
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 538 Algorithms for Calculation of the Shock Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 539 Choice of the Digitization Frequency of the Signal
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5310 Use of Shock Response Spectra for the Study of Systems with Several Degrees of Freedom
                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 54 Pyroshocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 55 Use of Shock Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 551 Severity Comparison of Several Shocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 552 Test Specification Development from Real Environment Data
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5521 Synthesis of Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5522 Nature of the Specification
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5523 Choice of Shape
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5524 Amplitude
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5525 Duration
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5526 Difficulties
                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 56 Standards
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 561 Types of Standards
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 562 Installation Conditions of Test Item
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 563 Uncertainty Factor
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 564 Bump Test
                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 57 Damage Boundary Curve
                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 571 Definition
                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 572 Analysis of Test Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 58 Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 581 Main Types
                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 582 Impact Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5821 Universal Shock-Test Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 58211 Impact Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 58212 Impulse Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 583 Shock Simulators (Programmers)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5831 Half-Sine Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58311 Shock Duration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58312 Impact Velocity
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58313 Maximum Deformation of the Shock Simulator (Programmer)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58314 Shock Amplitude
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58315 Characteristics of the Target
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5832 Terminal Peak Sawtooth Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5833 Rectangular Pulse ndash Trapezoidal Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5834 Universal Shock Simulator (Programmer)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 58341 Generating a Half-Sine Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 58342 Generating a Terminal Peak Sawtooth Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 58343 Trapezoidal Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 584 Limitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5841 Limitations of the Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5842 Limitations of Shock Simulators
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 585 Pneumatic Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 586 High Impact Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5861 Lightweight High Impact Shock Machine
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5862 Medium Weight High Impact Shock Machine
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 587 Specific Test Facilities
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 59 Generation of Shock Using Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 591 Principle Behind the Generation of a Simple Shape Signal versus Time
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 592 Main Advantages
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 593 Pre- and Postshocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5931 Requirements
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5932 Solutions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 59321 Optimized Pre- and Postpulses
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5933 Incidence on the Shock Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 594 Limitations of Electrodynamic Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5941 Mechanical Limitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 59411 Abacuses
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5942 Electronic Limitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 595 The Use of Electrohydraulic Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 510 Control by a Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 5101 Principle
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 5102 Principal Shapes of Elementary Signals
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 51021 Decaying Sinusoid
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 51022 ZERD Function
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 51023 WAVSIN Waveform
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 5103 Comparison of WAVSIN SHOC Waveforms and Decaying Sinusoid
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 5104 Criticism of Control by a Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 511 Pyrotechnic Shock Simulation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5111 Simulation Using Pyrotechnic Facilities
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5112 Simulation Using Metal-to-Metal Impact
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5113 Simulation Using Electrodynamic Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5114 Simulation Using Conventional Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53191ch6
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Chapter 6 Machine Condition Monitoring and Fault Diagnostics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 61 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 62 Machinery Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 621 Causes of Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 622 Types of Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 623 Frequency of Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 63 Basic Maintenance Strategies
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 631 Run-to-Failure (Breakdown) Maintenance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 632 Scheduled (Preventative) Maintenance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 633 Condition-Based (Predictive Proactive Reliability Centered On-Condition) Maintenance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 64 Factors Which Influence Maintenance Strategy
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 65 Machine Condition Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 651 Periodic Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 652 Continuous Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 66 Transducer Selection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 661 Noncontact Displacement Transducers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 662 Velocity Transducers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 663 Acceleration Transducers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 67 Transducer Location
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 68 Recording and Analysis Instrumentation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 681 Vibration Meters
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 682 Data Collectors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 683 Frequency-Domain Analyzers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 684 Time-Domain Instruments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 685 Tracking Analyzers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 69 Display Formats and Analysis Tools
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 691 Time Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6911 Time-Waveform Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6912 Time-Waveform Indices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6913 Time-Synchronous Averaging
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6914 Negative Averaging
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6915 Orbits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6916 Probability Density Functions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6917 Probability Density Moments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 692 Frequency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6921 Band-Pass Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6922 Shock Pulse (Spike Energy)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6923 Enveloped Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6924 Signature Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6925 Cascades (Waterfall Plots)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6926 Masks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6927 Frequency-Domain Indices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 693 Modal Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 694 Quefrency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 610 Fault Detection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 6101 Standards
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61011 Standards Based on Machinery Type
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61012 Standards Based on Vibration Severity
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 6102 Acceptance Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 61021 Statistical Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 6103 Frequency-Domain Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61031 Limited Band Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61032 Constant Bandwidth Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61033 Constant Percentage Bandwidth Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 611 Fault Diagnostics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 6111 Forcing Functions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61111 Unbalance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61112 Misalignment
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61113 Mechanical Looseness
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61114 Soft Foot
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61115 Rubs
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61116 Resonances
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61117 Oil Whirl
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61118 Oil Whip
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61119 Structural Vibrations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 611110 Foundation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 6112 Specific Machine Components
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 61121 Damaged or Worn Rolling-Element Bearings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 61122 Damaged or Worn Gears
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 6113 Specific Machine Types
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61131 Pumps
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61132 Fans
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61133 Electric Motors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61134 Steam and Gas Turbines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61135 Compressors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61136 Reciprocating Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 6114 Advanced Fault Diagnostic Techniques
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 53191ch7
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • Chapter 7 Vibration-Based Tool Condition Monitoring Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 71 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 72 Mechanics of Turning
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 721 General Terms
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 722 Chatter Vibrations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 723 Tool Wear
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7231 Tool Failure Mechanisms
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7232 Tool Failure Modes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7233 Tool Wear Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7234 Tool Wear Stages
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 73 Vibration Signal Recording
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 731 Direct and Indirect Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 732 Sensor Requirements for Tool Wear Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 733 Force Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7331 Direct Measurement Dynamometers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7332 Indirect Force Sensors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7333 Piezoelectric Strain Sensors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7334 Resistance Strain Gauges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7335 Customized Force Sensors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 734 Acceleration Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 735 Acoustic Emission Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 736 Sensor Comparisons
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 74 Signal Processing for Sensor-Based Tool Condition Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 741 Feature Extraction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7411 Time Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7412 Frequency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7413 Statistical Processing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7414 TimendashFrequency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 742 Feature Selection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 75 Wear ModelDecision-Making for Sensor-Based Tool Condition Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 751 Trending Threshold
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 752 Neural Networks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7521 Unsupervised Networks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7522 Supervised Networks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 753 Fuzzy Logic
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 754 Other Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 76 Conclusion
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53191ch8
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Chapter 8 Fault Diagnosis of Helicopter Gearboxes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 81 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 82 Abnormality Scaling
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 83 The Structure-Based Connectionist Network
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 84 Sensor Location Selection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 841 Coverage Index
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 842 Overlap Index
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 843 Monitoring Effectiveness
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 85 A Case Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 851 Structural and Featural Influences
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 852 Evaluation of Influences
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 853 Fault Detection Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 854 Fault Diagnostic Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 8541 Faulty Subsystem Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 8542 Faulty Component Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 855 Sensor Location Evaluation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 856 Sensor Location Validation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 86 Conclusion
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 53191ch9
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Chapter 9 Vibration Suppression and Monitoring in Precision Motion Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 91 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 92 Mechanical Design to Minimize Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 921 Stability and Static Determinacy of Machine Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 922 Two-Dimensional Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 923 Three-Dimensional Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 93 Adaptive Notch Filter
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 931 Fast Fourier Transform
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 932 Simulation and Experiments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 94 Real-Time Vibration Analyzer
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 941 Learning Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 942 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 943 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 944 Experiments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 9441 Input Variables mdash the Evaluation Criteria
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 94411 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 94412 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 9442 Evaluation Rules
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 94421 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 94422 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 9443 Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 94431 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 94432 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 95 Practical Insights and Case Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 96 Conclusions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 53191ch10
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Chapter 10 Vibration and Shock Problems of Civil Engineering Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 101 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 102 Earthquake-Induced Vibration of Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1021 Seismicity and Ground Motions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1022 Influence of Local Site Conditions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1023 Response of Structures to Ground Motions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1024 Dynamic Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10241 Equations of Motion for Linear Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10242 Equations of Motion for Linear Multiple-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1025 Earthquake Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10251 Elastic Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10252 Smoothed Design Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10253 Ductility-Modified Response Spectrum Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1026 Design Philosophy and the Code Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10261 Performance-Based Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1027 Analysis Options for Earthquake Effects
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10271 Dynamic Time History Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10272 Response Spectrum Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 102721 Response Spectrum Analysis of Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 102722 Response Spectrum Analysis of Multi-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10273 Equivalent Static Analysis (Force-Based Approach)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10274 Displacement-Based Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1028 SoilndashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1029 Active and Passive Control Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 10210 Worked Examples
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 103 Dynamic Effects of Wind Loading on Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1031 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1032 Wind Speed
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1033 Design Structures for Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10331 Types of Wind Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10332 Design Criteria
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10333 Static Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1034 Along and Across-Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10341 Along-Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10342 Across-Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1035 Wind Tunnel Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1036 Comfort Criteria Human Response to Building Motion
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1037 Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1038 Comparison with Earthquake Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 104 Vibrations Due to Fluid ndashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1041 Added Mass and Inertial Coupling
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1042 Wave-Induced Vibration of Structure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 105 Blast Loading and Blast Effects on Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1051 Explosions and Blast Phenomenon
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1052 Explosive Air-Blast Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10521 Blast Wave Scaling Laws
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10522 Prediction of Blast Pressure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1053 Gas Explosion Loading and Effect of Internal Explosions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1054 Structural Response to Blast Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10541 Elastic Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10542 Elasto-Plastic Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1055 Material Behaviors at High Strain Rate
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10551 Dynamic Properties of Concrete under High Strain Rates
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10552 Dynamic Properties of Reinforcing Steel under High Strain Rates
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1056 Failure Modes of Blast-Loaded Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10561 Global Structural Behavior
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10562 Localized Structural Behavior
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10563 PressurendashImpulse ( PndashI ) Diagrams
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1057 Blast WavendashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1058 Effect of Ground Shocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10581 Loads from Air-Induced Ground Shock
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10582 Loads from Direct Ground Shock
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1059 Technical Design Manuals for Blast-Resistant Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 10510 Computer Programs for Blast and Shock Effects
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 106 Impact Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1061 Structural Impact between Two Bodies mdash Hard Impact and Soft Impact
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1062 Example mdash Aircraft Impact
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 107 Floor Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1071 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1072 Types of Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10721 Walking
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10722 Rhythmic Activities
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10723 Mechanical Equipment
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10724 Analysis Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1073 Natural Frequency of Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10731 Computing the Natural Frequency
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10732 Computing Deflection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10733 Damping
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10734 Resonance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1074 Vibration Caused by Walking
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10741 Minimum Natural Frequency
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1075 Design for Rhythmic Excitation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10751 Harmonics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10752 Minimum Natural Frequency
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1076 Example mdash Vibration Analysis of a Reinforced Concrete Floor
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 53191ch11
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Chapter 11 Seismic Base Isolation and Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 111 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1111 From Ductility Design to Base Isolation and Control Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1112 The Importance of Reducing Seismic Input and Response
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 112 Seismic Base Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1121 Historical Development of Base Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1122 Basic Principle
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1123 Issues in Seismic Base Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11231 Performance Criteria
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11232 Type of Structure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11233 Site Characteristics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11234 Retrofit Issues
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11235 Design of Building Services
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11236 Expected Life of Isolator
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1124 Seismic Isolation Devices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11241 Laminated Rubber Bearings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11242 Lead Rubber Bearing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11243 Friction-Based Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11244 Other Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1125 Design of Isolation Devices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11251 High-Damping Rubber Bearing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112511 Stability against Buckling
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112512 Stability against Roll Out
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11252 Lead Rubber Bearings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112521 Design of Lead Plug
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112522 Design of Laminated Rubber Bearing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11253 Design of Friction Pendulum System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1126 Verification of Properties of Isolation Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11261 Tests for Isolation Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 112611 System Characterization Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 112612 Prototype Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 112613 Quality Control Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11262 Uniform Building Code Recommendations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112621 Units Dependent on Loading Rates
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112622 Units Dependent on Bilateral Load
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112623 System Adequacy
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1127 Analysis of Base-Isolated Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11271 Modeling of a Superstructure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11272 Modeling of Isolation System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11273 Static Analysis Procedure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11274 Dynamic Analysis Procedure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 112741 Response Spectrum Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 112742 Time-History Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11275 Software for Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1128 Experimental Methods for Isolated Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1129 Implementation of Seismic Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11291 New Construction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112911 Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112912 Bridges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11292 Seismic Retrofit
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112921 Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112922 Bridges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11293 Other Implementations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 11210 Performance during Past Earthquakes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 112101 Performance of Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 112102 Performance of Bridges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 113 Seismic Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1131 Historical Development of Seismic Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1132 Basic Principles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11321 Passive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11322 Active Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11323 Semiactive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11324 Hybrid Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11325 Categorization of Basic Principles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1133 Important Issues in Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11331 SoilndashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11332 DevicendashStructure Interaction and Time Delay
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11333 Design Guidelines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1134 Vibration-Control Devices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11341 Passive Control Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113411 Metallic Yielding Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113412 Friction Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113413 Viscoelastic Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113414 Viscous Fluid Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113415 Tuned Mass Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11342 Active Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113421 Electromagnetic Actuator
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113422 Hydraulic Actuators
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11343 Semiactive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113431 Variable-Orifice Hydraulic Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113432 Controllable Fluid Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113433 Controllable Friction Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11344 Hybrid Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1135 Control Algorithm
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11351 Active Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11352 Semiactive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113521 Common Control Schemes for Controllable Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113522 Special Control Schemes for Controllable Damper
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1136 Experimental Performance Verification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11361 Shaking Table Tests of a Flexible Structural Model with TMD AMD and ATMD
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11362 Substructure Hybrid Test
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113621 Hybrid Tests Using Hydraulic Actuator
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113622 Hybrid Tests Using Shaking Table
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113623 Hybrid Tests Using Inertia-Force-Driven Loading System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1137 Implementations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11371 Semiactive Control of Full-Scale Structures Using Variable Joint Damper System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113711 Background of Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113712 Test System Set Up
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113713 Control Algorithm
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113714 Test Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11372 Application of Structural Control Technologies to Seismic Retrofit of a Cable-Stayed Bridge
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113721 Background of Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113722 Basic Concept of Seismic Retrofit
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113723 Modal Shape Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113724 Time-History Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113725 Soil ndash Structure Interaction Effect
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113726 Semiactive Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53191ch12
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Chapter 12 Seismic Random Vibration of Long-Span Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 121 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1211 Basic Concepts of Random Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12111 Stationary Random Process
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12112 Nonstationary Random Process
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1212 Three Methods for Structural Seismic Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12121 Response Spectrum Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12122 Time-History Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12123 Random Vibration Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 121231 Davenport Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 121232 Vanmarcke Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 12124 Comparisons of the Three Seismic-Analysis Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 122 Seismic Random-Excitation Fields
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1221 Power Spectral Density of Spatially Varying Ground Acceleration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1222 Several Coherence Models
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12221 FengndashHu Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12222 Harichandran ndashVanmarcke Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12223 LohndashYeh Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12224 OliveirandashHaondashPenzien Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12225 LucondashWong Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12226 QundashWangndashWang Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1223 Generation of Ground Acceleration Power Spectral Density Curves from Acceleration Response Spectrum Curves
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12231 Kaul Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12232 Iteration Scheme
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1224 Seismic Equations of Motion of Long-Span Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1225 Seismic Waves and Their Geometrical Expressions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 123 Pseudoexcitation Method for Structural Random Vibration Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1231 Structures Subjected to Stationary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12311 Single Stationary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12312 Multiple Stationary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1232 Structures Subjected to Nonstationary Random Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12321 Structures Subjected to Uniformly Modulated Evolutionary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 123211 Single Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 123212 Multiple Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12322 Structures Subjected to Nonuniformly Modulated Evolutionary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 123221 Single Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 123222 Multiple Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1233 Precise Integration Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12331 Precise Integration of Exponential Matrices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12332 Particular Solutions and Precise Integration Formulas for Various Forms of Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 123321 Linear Loading Form (HPD-L Form)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 123322 Sinusoidal Loading Form (HPD-S Form)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 123323 Exponentially Decaying Sinusoidal Loading Form (HPD-E Form)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 124 Long-Span Structures Subjected to Stationary Random Ground Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1241 The Solution of Equations of Motion Using the Pseudoexcitation Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1242 Numerical Comparisons with Other Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12421 Song-Hua-Jiang Suspension Bridge
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 124211 All Supports Move Uniformly
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 124212 Wave Passage Effect Is Taken into Account
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 124213 Wave-Passage Effect and Incoherence Effect Are Jointly Taken into Account
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 12422 San Joaquin Concrete Bridge
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 125 Long-Span Structures Subjected to Nonstationary Random Ground Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1251 Modulation Functions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1252 The Formulas for Nonstationary Multiexcitation Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1253 Expected Extreme Values of Nonstationary Random Processes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1254 Numerical Comparisons with the Corresponding Stationary Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 126 Conclusions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 53191ch13
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Chapter 13 Seismic Qualification of Equipment
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 131 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 132 Distribution Qualification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1321 Drive-Signal Generation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1322 Distribution Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1323 Test Procedures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 133 Seismic Qualification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1331 Stages of Seismic Qualification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1332 Test Preliminaries
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1333 Single-Frequency Testing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1334 Multifrequency Testing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1335 Generation of RRS Specifications
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 53191ch14
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Chapter 14 Human Response to Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 141 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 142 Vibration Excitations on Humans
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1421 Excitation Characteristics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 143 Human Response to Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1431 Vibration Perception
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1432 Frequency Weighting Curve
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1433 Iso-Perception Curves
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1434 Detection Threshold Curve
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 144 Regulation of Human Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1441 Acceptable Vibration Levels in Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1442 Whole-Body Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1443 HandndashArm Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
Page 15: Vibration Monitoring, Testing, and Instrumentationpreview.kingborn.net › 646000 › d1a74678d91943e5ba1d5e... · The MEMS Handbook, Second Edition MEMS: Introduction and Fundamentals

Note that one instrument may perform the tasks

of more than one category listed here Also more

than one instrument may be needed to carry out

tasks in a single category In the following sections

we will provide some examples of the types of

vibration instrumentation giving characteristics

operating principles and important practical

considerations Also we will describe several

experiments which can be found in a typical

vibration laboratory

An experimental vibration system generally

consists of four main subsystems

1 Test object

2 Excitation system

3 Control system

4 Signal acquisition and modification system

These are schematically shown in Figure 12 Note that various components shown in Figure 11 may

be incorporated into one of these subsystems In particular component matching hardware and object

mounting fixtures may be considered interfacing devices that are introduced through the interaction

between the main subsystems as shown in Figure 12 Some important issues of vibration testing and

instrumentation are summarized in Box 11

12 Vibration Exciters

Vibration experimentation may require an external exciter to generate the necessary vibration This is the

case in controlled experiments such as product testing where a specified level of vibration is applied to the

test object and the resulting response is monitored A variety of vibration exciters are available with

different capabilities and principles of operation

Three basic types of vibration exciters (shakers) are widely used hydraulic shakers inertial shakers

and electromagnetic shakers The operation-capability ranges of typical exciters in these three categories

are summarized in Table 11 Stroke or maximum displacement is the largest displacement the exciter

is capable of imparting onto a test object whose weight is assumed to be within its design load limit

Maximum velocity and acceleration are similarly defined Maximum force is the largest force that could

be applied by the shaker to a test object of acceptable weight (one within the design load) The values

given in Table 11 should be interpreted with caution Maximum displacement is achieved only at very

low frequencies The achievement of maximum velocity corresponds to intermediate frequencies in the

operating frequency range of the shaker Maximum acceleration and force ratings are usually achieved at

high frequencies It is not feasible for example to operate a vibration exciter at its maximum

displacement and its maximum acceleration simultaneously

Consider a loaded exciter that is executing harmonic motion Its displacement is given by

x frac14 s sin vt eth11THORN

in which s is the displacement amplitude (or stroke) Corresponding velocity and acceleration are

_x frac14 sv cos vt eth12THORN

eurox frac14 2sv2sin vt eth13THORN

SignalModification

System

TestObject

ControlSystem

VibrationExciter (Shaker)

System

FIGURE 12 Interactions between major subsystems of

an experimental vibration system

Vibration Instrumentation 1-3

53191mdash522007mdash1201mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

If the velocity amplitude is denoted by v and the acceleration amplitude by a it follows from Equation

12 and Equation 13 thatv frac14 vs eth14THORN

and

a frac14 vv eth15THORN

Box 11

VIBRATION INSTRUMENTATION

Vibration Testing Applications for Products

Design and Development Production Screening and Quality Assessment Utilization and Qualification for Special Applications

Testing Instrumentation

Exciter (excites the test object) Controller (controls the exciter for accurate excitation) Sensors and Transducers (measure excitations and responses and provide excitation error

signals to controller) Signal Conditioning (converts signals to appropriate form) Recording and Display (perform processing storage and documentation)

Exciters

Shakers

1 Electrodynamic (high bandwidth moderate power complex and multifrequency

excitations)

2 Hydraulic (moderate to high bandwidth high power complex and multifrequency

excitations)

3 Inertial (low bandwidth low power single-frequency harmonic excitations)

TransientInitial Condition

1 Hammers (impulsive bump tests)

2 Cable Release (step excitations)

3 Drop (impulsive)

Signal Conditioning

Filters Amplifiers Amplifiers ModulatorsDemodulators ADCDAC

Sensors

Motion (displacement velocity acceleration) Force (strain torque)

Vibration Monitoring Testing and Instrumentation1-4

53191mdash522007mdash1201mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

TABLE 11 Typical Operation-Capability Ranges for Various Shaker Types

Shaker Type Typical Operational Capabilities

Frequency Maximum Displacement

(Stroke)

Maximum

Velocity

Maximum

Acceleration

Maximum

Force

Excitation

Waveform

Hydraulic

(electrohydraulic)

Low

(01ndash500 Hz)

High (20 in 50 cm) Intermediate

(50 insec

125 cmsec)

Intermediate

(20 g)

High (100000 lbf

450000 N)

Average flexibility (simple

to complex and random)

Inertial

(counter-rotating mass)

Intermediate

(2ndash50 Hz)

Low (1 in 25 cm) Intermediate

(50 insec

125 cmsec)

Intermediate

(20 g)

Intermediate

(1000 lbf 4500 N)

Sinusoidal only

Electromagnetic

(electrodynamic)

High

(2ndash10000 Hz)

Low (1 in 25 cm) Intermediate

(50 insec

125 cmsec)

High (100 g) Low to intermediate

(450 lbf 2000 N)

High flexibility and accuracy

(simple to complex and

random)

VibrationInstru

mentation

1-5

53191mdash522007mdash

1201mdashSENTHILKUMARmdash246494mdash

CRCndashpp1ndash112

copy 2007 by Taylor amp Francis Group LLC

An idealized performance curve of a shaker

has a constant displacementndashamplitude region a

constant velocityndashamplitude region and a con-

stant accelerationndashamplitude region for low

intermediate and high frequencies respectively

in the operating frequency range Such an ideal

performance curve is shown in Figure 13(a) on a

frequencyndashvelocity plane Logarithmic axes are

used In practice typical shaker performance

curves would be fairly smooth yet nonlinear

curves similar to those shown in Figure 13(b)

As the mass increases the performance curve

compresses Note that the acceleration limit of a

shaker depends on the mass of the test object

(load) Full load corresponds to the heaviest object

that could be tested The ldquono loadrdquo condition

corresponds to a shaker without a test object To

standardize the performance curves they are

usually defined at the rated load of the shaker A

performance curve in the frequencyndashvelocity

plane may be converted to a curve in the

frequencyndashacceleration plane simply by increasing

the slope of the curve by a unit magnitude (ie

20 dbdecade)

Several general observations can be made from

Equation 14 and Equation 15 In the constant-

peak displacement region of the performance

curve the peak velocity increases proportionally

with the excitation frequency and the peak

acceleration increases with the square of the excitation frequency In the constant-peak velocity region

the peak displacement varies inversely with the excitation frequency and the peak acceleration increases

proportionately In the constant-peak acceleration region the peak displacement varies inversely with the

square of the excitation frequency and the peak velocity varies inversely with the excitation frequency

This further explains why rated stroke maximum velocity and maximum acceleration values are not

simultaneously realized

121 Shaker Selection

Vibration testing is accomplished by applying a specified excitation to the test package using a shaker

apparatus and monitoring the response of the test object Test excitation may be represented by its

response spectrum The test requires that the response spectrum of the actual excitation known as the

test response spectrum (TRS) envelops the response spectrum specified for the particular test known as

the required response spectrum (RRS)

A major step in the planning of any vibration testing program is the selection of a proper shaker

(exciter) system for a given test package The three specifications that are of primary importance in

selecting a shaker are the force rating the power rating and the stroke (maximum displacement) rating

Force and power ratings are particularly useful in moderate to high frequency excitations and the stroke

rating is the determining factor for low frequency excitations In this section a procedure is given to

determine conservative estimates for these parameters in a specified test for a given test package

Frequency domain considerations are used here

Stroke

Limit M

ax

Acceleration

MaxVelocity

Peak

Vel

ocity

(cm

s)

01 1 10 100

FullLoad

NoLoad

Frequency (Hz)(a)

Peak

Vel

ocity

(cm

s)

100

10

1

100

10

1

01 1 10 100

FullLoad

NoLoad

Frequency (Hz)(b)

FIGURE 13 Performance curve of a vibration exciter

in the frequencyndashvelocity plane (log) (a) ideal (b)

typical

Vibration Monitoring Testing and Instrumentation1-6

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copy 2007 by Taylor amp Francis Group LLC

1211 Force Rating

In the frequency domain the (complex) force at the exciter (shaker) head is given by

F frac14 mHethvTHORNasethvTHORN eth16THORNin which v is the excitation frequency variable m is the total mass of the test package including

mounting fixture and attachments asethvTHORN is the Fourier spectrum of the support-location (exciter head)

acceleration and H(v) is frequency response function that takes into account the flexibility and

damping effects (dynamics) of the test package apart from its inertia In the simplified case where the

test package can be represented by a simple oscillator of natural frequency vn and damping ratio by zt

this function becomes

HethvTHORN frac14 1thorn 2jztv=vn=12 ethv=vnTHORN2 thorn 2jztv=vn eth17THORNin which j frac14 ffiffiffiffi

21p

This approximation is adequate for most practical purposes The static weight of the

test object is not included in Equation 16 Most heavy-duty shakers which are typically hydraulic

have static load support systems such as pneumatic cushion arrangements that can exactly balance the

dead load The exciter provides only the dynamic force In cases where shaker directly supports the

gravity load in the vertical test configuration Equation 16 should be modified by adding a term to

represent this weight

A common practice in vibration test applications is to specify the excitation signal by its response

spectrum This is simply the peak response of a simple oscillator expressed as a function of its natural

frequency when its support location is excited by the specified signal Clearly the damping of the simple

oscillator is an added parameter in a response spectrum specification Typical damping ratios ethzrTHORN used inresponse spectra specifications are less than 01 (or 10) It follows that an approximate relationship

between the Fourier spectrum of the support acceleration and its response spectrum is

as frac14 2jzrarethvTHORN eth18THORNThe magnitude larethvTHORNl is the response spectrumEquation 18 substituted into Equation 16 gives

F frac14 mHethvTHORN2jzrarethvTHORN eth19THORNIn view of Equation 17 for test packages having low damping the peak value of H(v) is

approximately 1=eth2jztTHORN this should be used in computing the force rating if the test package has a

resonance within the frequency range of testing On the other hand if the test package is assumed to be

rigid then HethvTHORN oslash 1 A conservative estimate for the force rating is

Fmax frac14 methzr=ztTHORNlarethvTHORNlmax eth110THORNIt should be noted that larethvTHORNlmax is the peak value of the specified (required) response spectrum (RRS)

for acceleration

1212 Power Rating

The exciter head does not develop its maximum force when driven at maximum velocity Output power

is determined by using

p frac14 Refrac12FvsethvTHORN eth111THORNin which vsethvTHORN is the Fourier spectrum of the exciter velocity and Re [ ] denotes the real part of a complex

function Note that as frac14 jvvs Substituting Equation 16 and Equation 18 into Equation 111 gives

p frac14 eth4mz2r =vTHORNRefrac12jHethvTHORNa2r ethvTHORN eth112THORNIt follows that a conservative estimate for the power rating is

pmax frac14 2methz2r =ztTHORNfrac12larethvTHORNl2=v max eth113THORN

Vibration Instrumentation 1-7

53191mdash522007mdash1201mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

Representative segments of typical acceleration RRS curves have slope n as given by

a frac14 k1vn eth114THORN

It should be clear from Equation 113 that the maximum output power is given by

pmax frac14 k2v2n21 eth115THORN

This is an increasing function for n 1=2 and a decreasing function for n 1=2 It follows that the power

rating corresponds to the highest point of contact between the acceleration RRS curve and a line of slope

equal to 12 A similar relationship may be derived if velocity RRS curves (having slopes n2 1) are used

1213 Stroke Rating

From Equation 18 it should be clear that the Fourier spectrum xs of the exciter displacement time

history can be expressed as

xs frac14 2zrarethvTHORN=jv2 eth116THORNAn estimate for stroke rating is

xmax frac14 2zrfrac12larethvTHORNl=v2 max eth117THORNThis is of the form

xmax frac14 kvn22 eth118THORNIt follows that the stroke rating corresponds to the highest point of contact between the acceleration

RRS curve and a line of slope equal to two

Example 11

A test package of overall mass 100 kg is to be

subjected to dynamic excitation represented by the

acceleration RRS (at 5 damping) as shown in

Figure 14 The estimated damping of the test

package is 7 The test package is known to have a

resonance within the frequency range of the

specified test Determine the exciter specifications

for the test

Solution

From the development presented in the previous

section it is clear that the point F (or P) in

Figure 14 corresponds to the force and output

power ratings and the point S corresponds to

the stroke rating The co-ordinates of these

critical points are F P frac14 eth42 Hz 40 gTHORN and S frac14 eth08 Hz 075 gTHORN Equation 110 gives the force

rating as

Fmax frac14 100 pound eth005=007THORN pound 40 pound 981 N frac14 2803 N

Equation 113 gives the power rating as

pmax frac14 2 pound 100 pound eth0052=007THORN pound frac12eth40 pound 981THORN2=42 pound 2p watts frac14 417 W

Equation 117 gives the stroke rating as

xmax frac14 2 pound 005 pound frac12eth075 pound 98THORN=eth08 pound 2pTHORN2 m frac14 3 cm

Acc

eler

atio

n(g

)

Con

stan

t Dis

plac

emen

t

Constant Velo

city

Frequency (Hz)

S

FP

0101

10 10 100

10

10

FIGURE 14 Test excitation specified by an accelera-

tion RRS (5 damping)

Vibration Monitoring Testing and Instrumentation1-8

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copy 2007 by Taylor amp Francis Group LLC

1214 Hydraulic Shakers

A typical hydraulic shaker consists of a piston-cylinder arrangement (also called a ram) a servo-valve a

fluid pump and a driving electric motor Hydraulic fluid (oil) is pressurized (typical operating pressure

4000 psi) and pumped into the cylinder through a servo-valve by means of a pump that is driven by an

electric motor (typical power 150 hp) The flow (typical rate 100 galmin) that enters the cylinder is

controlled (modulated) by the servo-valve which in effect controls the resulting piston (ram) motion

A typical servo-valve consists of a two-stage spool valve which provides a pressure difference and a

controlled (modulated) flow to the piston which sets it in motion

The servo-valve itself is moved by means of a linear torque motor which is driven by the excitation-

input signal (electrical) A primary function of the servo-valve is to provide a stabilizing feedback to the

ram In this respect the servo-valve complements the main control system of the test setup The ram is

coupled to the shaker table by means of a link with some flexibility The cylinder frame is mounted on the

support foundation with swivel joints This allows for some angular and lateral misalignment which

might be caused primarily by test-object dynamics as the table moves

Two-degree-of-freedom (Two-DoF) testing requires two independent sets of actuators and three-DoF

testing requires three independent actuator sets Each independent actuator set can consist of several

actuators operated in parallel using the same pump and the same excitation-input signal to the torque

motors

If the test table is directly supported on the vertical actuators they must withstand the total dead

weight (ie the weight of the test table the test object the mounting fixtures and the instrumentation)

This is requirement is usually prevented by providing a pressurized air cushion in the gap between the

test table and the foundation walls Air should be pressurized so as to balance the total dead weight

exactly (typical required gage pressure 3 psi)

Figure 15(a) shows the basic components of a typical hydraulic shaker The corresponding

operational block diagram is shown in Figure 15(b) It is desirable to locate the actuators in a pit in the

test laboratory so that the test tabletop is flushed with the test laboratory floor under no-load conditions

This minimizes the effort required to place the test object on the test table Otherwise the test object has

to be lifted onto the test table with a forklift Also installation of an aircushion to support the system

dead weight is difficult under these circumstances of elevated mounting

Hydraulic actuators are most suitable for heavy load testing and are widely used in industrial and civil

engineering applications They canbeoperated at very low frequencies (almost direct current [DC]) aswell

as at intermediate frequencies (see Table 11) Large displacements (stroke) are possible at low frequencies

Hydraulic shakers have the advantage of providing high flexibility of operation during the test their

capabilities include variable-force and constant-force testing and wide-band random-input testing The

velocity and acceleration capabilities of hydraulic shakers are moderate Although any general excitation-

input motion (for example sine wave sine beat wide-band random) can be used in hydraulic shakers

faithful reproduction of these signals is virtually impossible at high frequencies because of distortion and

higher-order harmonics introduced by the high noise levels that are common in hydraulic systems This

is only a minor drawback in heavy-duty intermediate-frequency applications Dynamic interactions are

reduced through feedback control

1215 Inertial Shakers

In inertial shakers or ldquomechanical excitersrdquo the force that causes the shaker-table motion is generated by

inertia forces (accelerating masses) Counter-rotating-mass inertial shakers are typical in this category

To understand their principle of operation consider two equal masses rotating in opposite directions at

the same angular speed v and in the same circle of radius r (see Figure 16) This produces a resultant

force equal to 2mv2r cos vt in a fixed direction (the direction of symmetry of the two rotating arms)

Consequently a sinusoidal force with a frequency of v and an amplitude proportional to v2 is generated

This reaction force is applied to the shaker table

Figure 17 shows a sketch of a typical counter-rotating-mass inertial shaker It consists of two identical

rods rotating at the same speed in opposite directions Each rod has a series of slots in which to

Vibration Instrumentation 1-9

53191mdash522007mdash1201mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

place weights In this manner the magnitude of

the eccentric mass can be varied to achieve various

force capabilities The rods are driven by a

variable-speed electric motor through a gear

mechanism that usually provides several speed

ratios A speed ratio is selected depending on the

required test-frequency range The whole system is

symmetrically supported on a carriage that is

directly connected to the test table The test object

is mounted on the test table The preferred

mounting configuration is horizontal so that the

excitation force is applied to the test object in a

horizontal direction In this configuration there

are no variable gravity moments (weight pounddistance to center of gravity) acting on the drive

mechanism Figure 17 shows the vertical con-

figuration In dynamic testing of large structures

the carriage can be mounted directly on the

structure at a location where the excitation force

should be applied By incorporating two pairs of

counter-rotating masses it is possible to generate

test moments as well as test forces

FIGURE 15 A typical hydraulic shaker arrangement (a) schematic diagram (b) operational block diagram

m m

2mw2r cos wt

wtw w

wt

FIGURE 16 Principle of operation of a counter-

rotating-mass inertial shaker

Vibration Monitoring Testing and Instrumentation1-10

53191mdash522007mdash1201mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

Reaction-type shakers driven by inertia are widely used for the prototype testing of civil engineering

structures Their first application dates back to 1935 Inertial shakers are capable of producing

intermediate excitation forces The force generated is limited by the strength of the carriage frame The

frequency range of operation and the maximum velocity and acceleration capabilities are also

intermediate for inertial shakers whereas the maximum displacement capability is typically low A major

limitation of inertial shakers is that their excitation force is exclusively sinusoidal and that the force

amplitude is directly proportional to the square of the excitation frequency As a result complex and

random excitation testing constant-force testing (for example transmissibility tests and constant-force

sine-sweep tests) and flexibility to vary the force amplitude or the displacement amplitude during a test

are not generally feasible with this type of shakers Excitation frequency and amplitude can be varied

during testing however by incorporating a variable-speed drive for the motor The sinusoidal excitation

generated by inertial shakers is virtually undistorted which gives them an advantage over the other types

of shakers when used in sine-dwell and sine-sweep tests Small portable shakers with low-force capability

are available for use in on-site testing

1216 Electromagnetic Shakers

In electromagnetic shakers or ldquoelectrodynamic excitersrdquo the motion is generated using the principle of

operation of an electric motor Specifically the excitation force is produced when a variable excitation

signal (electrical) is passed through a moving coil placed in a magnetic field

The components of a commercial electromagnetic shaker are shown in Figure 18 A steady magnetic

field is generated by a stationary electromagnet that consists of field coils wound on a ferromagnetic base

that is rigidly attached to a protective shell structure The shaker head has a coil wound around it When

the excitation electrical signal is passed through this drive coil the shaker head which is supported on

flexure mounts will be set in motion The shaker head consists of the test table on which the test object

is mounted Shakers with interchangeable heads are available The choice of appropriate shaker head is

based on the geometry and mounting features of the test object The shaker head can be turned to

different angles by means of a swivel joint In this manner different directions of excitation (in biaxial

and triaxial testing) can be obtained

FIGURE 17 Sketch of a counter-rotating-mass inertial shaker

Vibration Instrumentation 1-11

53191mdash522007mdash1202mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

122 Dynamics of Electromagnetic Shakers

Consider a single axis electromagnetic shaker (Figure 18) with a test object having a single natural

frequency of importance within the test frequency range The dynamic interactions between the shaker

and the test object give rise to two significant natural frequencies (and correspondingly two significant

resonances) These appear as peaks in the frequency response curve of the test setup Furthermore the

natural frequency (resonance) of the test package alone causes a ldquotroughrdquo or depression (antiresonance)

in the frequency response curve of the overall test setup To explain this characteristic consider the

dynamic model shown in Figure 19 The following mechanical parameters are defined for

Figure 19(a) m k and b are the mass stiffness and equivalent viscous damping constant respectively

of the test package and me ke and be are the corresponding parameters of the exciter (shaker) Also in

the equivalent electrical circuit of the shaker head as shown in Figure 19(b) the following electrical

parameters are defined Re and Le are the resistance and (leakage) inductance and kb is the back

electromotive force (back emf) of the linear motor Assuming that the gravitational forces are supported

FIGURE 18 Schematic sectional view of a typical electromagnetic shaker manufactured by Bruel and Kjaer

Denmark

Vibration Monitoring Testing and Instrumentation1-12

53191mdash522007mdash1202mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

by the static deflections of the flexible elements and that the displacements are measured from the static

equilibrium position we have the following system equations

Test object meuroy frac14 2kethy2 yeTHORN2 beth_y2 _yeTHORN eth119THORNShaker head me euroye frac14 fe thorn kethy2 yeTHORN thorn beth_y2 _yeTHORN2 key 2 be _ye eth120THORN

Electrical Lediedt

thorn Reie thorn kb _ye frac14 vethtTHORN eth121THORN

The electromagnetic force fe generated in the shaker head is a result of the interaction of the magnetic

field generated by the current ie with coil of the moving shaker head and the constant magnetic field

(stator) in which the head coil is located Here we have

fe frac14 kbie eth122THORNNote that v(t) is the voltage signal that is applied by the amplifier to the shaker coil ye is the displacement

of the shaker head and y is the displacement response of the test package

It is assumed that kb has consistent electrical and mechanical units (Vmsec and NA) Usually

the electrical time constant of the shaker is quite small compared with the primarily mechanical

time constants of the shaker and the test package In such cases the Ledie=dt term in Equation 121 may

be neglected Consequently the equations from Equation 119 through Equation 122 may be

expressed in the Laplace (frequency) domain with the Laplace variable s taking the place of the derivative

d=dt as

ethms2 thorn bsthorn kTHORNy frac14 ethbsthorn kTHORNye eth123THORN

FIGURE 19 Dynamic models of an electromagnetic shaker and a flexible test package (a) mechanical model

(b) electrical model

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frac12mes2 thorn ethbthorn beTHORNsthorn ethkthorn keTHORN ye frac14 ethbsthorn kTHORNy thorn kb

Rev2

k2bs

Reye eth124THORN

It follows that the transfer function of the shaker head motion with respect to the excitation voltage is

given by

yevfrac14 kb

Re

DethsTHORNDdethsTHORN eth125THORN

where DethsTHORN is the characteristic function of the primary dynamics of the test object

DethsTHORN frac14 ms2 thorn bsthorn k eth126THORN

and DdethsTHORN is the characteristic function of the primary dynamic interactions between the shaker and thetest object

DcethsTHORN frac14 mmes4 thorn frac12methbe thorn bthorn boTHORN thornmeb s

3 thorn frac12methke thorn kTHORN thornmekthorn bethbe thorn boTHORN s2thorn frac12bke thorn ethbe thorn boTHORNk sthorn kke

eth127THORN

where

bo frac14 k2bRe

eth128THORN

It is clear that under low damping conditions DdethsTHORN will produce two resonances as it is fourth order in sand similarly DethsTHORN will produce one antiresonance (trough) corresponding to the resonance of the testobject Note that in the frequency domain s frac14 jv and hence the frequency response function given by

Equation 125 is in fact

yevfrac14 kb

Rb

DethjvTHORNDdethjvTHORN eth129THORN

The magnitude of this frequency response function for a typical test system is sketched in Figure 110

Note that this curve is for the ldquoopen-looprdquo case where there is no feedback from the shaker controller

In practice the shaker controller will be able

to compensate for the resonances and anti-

resonances to some degree depending on its

effectiveness

The main advantages of electromagnetic

shakers are their high frequency range of

operation their high degree of operating flexi-

bility and the high level of accuracy of the

generated shaker motion Faithful reproduction

of complex excitations is possible because of the

advanced electronics and control systems used in

this type of shakers Electromagnetic shakers are

not suitable for heavy-duty applications (large test

objects) however High test-input accelerations

are possible at high frequencies when electromag-

netic shakers are used but their displacement and

velocity capabilities are limited to low or

intermediate values (see Table 11)

100

10

1 10 100Excitation Frequency (Hz)

Antiresonance

Resonance

Shak

erD

ispl

acem

entM

agni

tude

Resonance

1000

FIGURE 110 Frequency response curve of a typical

electromagnetic shaker with a test object

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1221 Transient Exciters

Other varieties of exciters are commonly used in

transient-type vibration testing In these tests

either an impulsive force or an initial excitation is

applied to the test object and the resulting

response is monitored The excitations and the

responses are ldquotransientrdquo in this case Hammer

test drop tests and pluck tests fall into this

category For example a hammer test may be

conducted by hitting the object with an instru-

mented hammer and then measuring the response

of the object The hammer has a force sensor at its

tip as sketched in Figure 111 A piezoelectric or

strain-gage type force sensor may be used More

sophisticated hammers have impedance heads in

place of force sensors An impedance head

measures force and acceleration simultaneously

The results of a hammer test will depend on many

factors for example the dynamics of the hammer

body how firmly the hammer is held during the

impact how quickly the impact is applied and

whether there are multiple impacts

13 Control System

The two primary functions of the shaker control system in vibration testing are (1) to guarantee that the

specified excitation is applied to the test object and (2) to ensure that the dynamic stability (motion

constraints) of the test setup is preserved An operational block diagram illustrating these control

functions is given in Figure 112 The reference input to the control system represents the desired

excitation force that should be applied to the test object In the absence of any control however the force

reaching the test object will be distorted primarily because of (1) dynamic interactions and

nonlinearities of the shaker the test table the mounting fixtures the auxiliary instruments and the test

object itself (2) noise and errors in the signal generator amplifiers filters and other equipment and (3)

external loads and disturbances acting on the test object and other components (for example external

restraints aerodynamic forces friction) To compensate for these distorting factors response

measurements (displacements velocities acceleration and so on) are made at various locations in the

test setup and are used to control the system dynamics In particular the responses of the shaker the test

table and the test object are measured These responses are used to compare the actual excitation felt by

FIGURE 111 An instrumented hammer used in bump

tests or hammer tests

ExcitationInput

(Reference)

Feedback Paths

DriveSignal

ShakerResponse

TestTable

TestObject

Test ObjectResponse

Test TableResponseExciter

(Shaker)(Ram)

Controllerand

Amplifier

FIGURE 112 Operational block diagram illustrating a general shaker control system

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copy 2007 by Taylor amp Francis Group LLC

the test object at the shaker interface with the desired (specified) input The drive signal to the shaker is

modified depending on the error that is present

Two types of control are commonly employed in shaker apparatus simple manual control and

complex automatic control Manual control normally consists of simple open-loop trial-and-error

methods of manual adjustments (or calibration) of the control equipment to obtain a desired dynamic

response The actual response is usually monitored (on an oscilloscope or frequency analyzer screen for

example) during manual-control operations The pretest adjustments in manual control can be very

time-consuming as a result the test object might be subjected to overtesting which could produce

cumulative damage is undesirable and could defeat the test purpose Furthermore the calibration

procedure for the experimental setup must be repeated for each new test object

The disadvantages ofmanual control suggest that automatic control is desirable in complex test schemes

in which high accuracy of testing is desired The first step of automatic control involves automatic

measurement of the system response using control sensors and transducers The measurement is then fed

back into the control system which instantaneously determines the best drive signal to actuate the shaker

in order to get the desired excitation This may be done by either analog or digital methods

Primitive control systems require an accurate mathematical description of the test object This

dependency of the control system on the knowledge of test-object dynamics is clearly undesirable

Performance of a good control system should not be considerably affected by the dynamic interactions

and nonlinearities of the test object or by the nature of the excitation Proper selection of feedback signals

and control-system components can reduce such effects and will make the system robust

In the response-spectrum method of vibration testing it is customary to use displacement control at

low frequencies velocity control at intermediate frequency and acceleration control at high frequencies

This necessitates feedback of displacement velocity and acceleration responses Generally however the

most important feedback is the velocity feedback In sine-sweep tests the shaker velocity must change

steadily over the frequency band of interest In particular the velocity control must be precise near the

resonances of the test object Velocity (speed) feedback has a stabilizing effect on the dynamics which is

desirable This effect is particularly useful in ensuring stability in motion when testing is done near

resonances of lightly damped test objects On the contrary displacement (position) feedback can have a

destabilizing effect on some systems particularly when high feedback gains are used

The controller usually consists of various instruments equipment and computation hardware and

software Often the functions of the data-acquisition and processing system overlap with those of the

controller to some extent As an example consider the digital-controller of vibration testing apparatus

First the responses are measured through sensors (and transducers) filtered and amplified

(conditioned) These data channels may be passed through a multiplexer whose purpose is to select

one data channel at a time for processing Most modern data acquisition hardware does not need a

separate multiplexer to handle multiple signals The analog data are converted into digital data using

analog-to-digital converters (ADCs) The resulting sampled data are stored on a disk or as a block data in

the computer memory The reference input signal (typically a signal recorded on an FM tape) is also

sampled (if it is not already in the digital form) using an ADC and fed into the computer Digital

processing is done on the reference signal and the response data with the objective of computing the

command signal to drive the shaker The digital command signal is converted into an analog signal using

a digital-to-analog converter (DAC) and amplified (conditioned) before it is used to drive the exciter

The nature of the control components depends to a large extent on the nature and objectives of the

particular test to be conducted Some of the basic components in a shaker controller are described in

the following subsections

131 Components of a Shaker Controller

1311 Compressor

A compressor circuit is incorporated in automatic excitation control devices to control the excitation-

input level automatically The level of control depends on the feedback signal from a control sensor and

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the specified (reference) excitation signal Usually the compressor circuit is included in the excitation-

signal generator (for example in a sine generator) The control by this means may be done on the basis of

a single-frequency component (eg the fundamental frequency)

1312 Equalizer (Spectrum Shaper)

Random-signal equalizers are used to shape the spectrum of a random signal in a desired manner In

essence and equalizer consists of a bank of narrow-band filters (for example 80 filters) in parallel over

the operating frequency range By passing the signal through each filter the spectral density (or the mean

square value) of the signal in that narrow frequency band (for example each one-third-octave band) is

determined This is compared with the desired spectral level and automatic adjustment is made in that

filter in case there is an error In some systems response-spectrum analysis is made in place of power

spectral density analysis In that case the equalizer consists of a bank of simple oscillators whose

resonant frequencies are distributed over the operating frequency range of the equalizer The feedback

signal is passed through each oscillator and the peak value of its output is determined This value is

compared with the desired response spectrum value at that frequency If there is an error automatic gain

adjustment is made in the appropriate excitation signal components

Random-noise equalizers are used in conjunction with random signal generators They receive

feedback signals from the control sensors In some digital control systems there are algorithms (software)

that are used to iteratively converge the spectrum of the excitation signal felt by the test object into the

desired spectrum

1313 Tracking Filter

Many vibration tests are based on single-frequency excitations In such cases the control functions

should be performed on the basis of the amplitudes of the fundamental-frequency component of the

signal A tracking filter is simply a frequency-tuned band-pass filter It automatically tunes the center

frequency of its very narrow-band-pass filter to the frequency of a carrier signal Then when a noisy

signal is passed through the tuned filter the output of the filter will be the required fundamental

frequency component in the signal Tracking filters also are useful in obtaining amplitudendashfrequency

plots using an XndashY plotter In such cases the frequency value comes from the signal generator (sweep

oscillator) which produces the carrier signal to the tracking filter The tracking filter then determines the

corresponding amplitude of a signal that is fed into it Most tracking filters have dual channels so that two

signals can be handled (tracked) simultaneously

1314 Excitation Controller (Amplitude Servo-Monitor)

An excitation controller is typically an integral part of the signal generator It can be set so that automatic

sweep between two frequency limits can be performed at a selected sweep rate (linear or logarithmic)

More advanced excitation controllers have the capability of an automatic switch-over between constant-

displacement constant-velocity and constant-acceleration excitation-input control at specified

frequencies over the sweep frequency interval Consequently integrator circuits should be present

within the excitation controller unit to determine velocities and displacements from acceleration signals

Sometimes integration is performed by a separate unit called a vibration meter This unit also offers

the operator the capability of selecting the desired level of each signal (acceleration velocity or

displacement) There is an automatic cut-off level for large displacement values that could result from

noise in acceleration signals A compressor is also a subcomponent of the excitation controller The

complete unit is sometimes known as an amplitude servo-monitor

132 Signal-Generating Equipment

Shakers are force-generating devices that are operated using drive (excitation) signals generated from a

source The excitation-signal source is known as the signal generator Three major types of signal

generators are used in vibration testing applications (1) oscillators (2) random-signal generators and

(3) storage devices In some units oscillators and random-signal generators are combined We shall

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copy 2007 by Taylor amp Francis Group LLC

discuss these two generators separately however because of their difference in function It also should be

noted that almost any digital signal (deterministic or random) can be generated by a digital computer

using a suitable computer program the signal eventually can be passed through a DAC to obtain

the corresponding analog signal These lsquodigitalrsquo signal generators along with analog sources such as

magnetic tape players (FM) are classified into the category of storage devices

The dynamic range of equipment is the ratio of the maximum and minimum output levels (expressed

in decibels) at which it is capable of operating without significant error This is an important specification

for many types of equipment particularly for signal-generating devices The output level of the signal

generator should be set to a value within its dynamic range

1321 Oscillators

Oscillators are essentially single-frequency generators Typically sine signals are generated but other

waveforms (such as rectangular and triangular pulses) are also available in most oscillators Normally

an oscillator has two modes of operation (1) sweeping up and down between two frequency limits and

(2) dwelling at a specified frequency In the sweep operation the sweep rate should be specified This can

be done either on a linear scale (Hzmin) or on a logarithmic scale (octavesmin) In the dwell operation

the frequency points (or intervals) should be specified In either case a desired signal level can be chosen

using the gain-control knob An oscillator that is operated exclusively in the sweep mode is called a sweep

oscillator

The early generation of oscillators employed variable inductor-capacitor types of electronic circuits to

generate signals oscillating at a desired frequency The oscillator is tuned to the required frequency by

varying the capacitance or inductance parameters A DC voltage is applied to energize the capacitor

and to obtain the desired oscillating voltage signal which subsequently is amplified and conditioned

Modern oscillators use operational amplifier circuits along with resistor capacitor and semiconductor

(SC) elements Also common are crystal (quartz) parallel-resonance oscillators used to generate voltage

signals accurately at a fixed frequency The circuit is activated using a DC-voltage source Other

frequencies of interest are obtained by passing this high-frequency signal through a frequency converter

The signal is then conditioned (amplified and filtered) Required shaping (for example rectangular

pulse) is obtained using a shape circuit Finally the required signal level is obtained by passing the

resulting signal through a variable-gain amplifier A block diagram of an oscillator illustrating various

stages in the generation of a periodic signal is given in Figure 113

A typical oscillator offers a choice of several (typically six) linear and logarithmic frequency ranges and

a sizable level of control capability (for example 80 dB) Upper and lower frequency limits in a sweep can

be preset on the front panel to any of the available frequency ranges Sweep-rate settings are continuously

DC Voltage

Oscillator

FrequencySpecification

FrequencyConverter

FilterAmplifier

ShaperPeriodicSignal

FrequencyCounter

Fixed-FrequencySignal

Variable-GainOutput

Amplifier

SignalSpecification

LevelSpecification

FIGURE 113 Block diagram of an oscillator-type signal generator

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copy 2007 by Taylor amp Francis Group LLC

  • 53191fm
    • Vibration Monitoring Testing and Instrumentation
      • Preface
      • Acknowledgments
      • Editor-in-Chief
      • Contributors
      • Contents
      • Related Titles
          • 53191ch1
            • Table of Contents
            • Chapter 1 Vibration Instrumentation
              • Summary
              • 11 Introduction
              • 12 Vibration Exciters
                • 121 Shaker Selection
                  • 1211 Force Rating
                  • 1212 Power Rating
                  • 1213 Stroke Rating
                  • 1214 Hydraulic Shakers
                  • 1215 Inertial Shakers
                  • 1216 Electromagnetic Shakers
                    • 122 Dynamics of Electromagnetic Shakers
                      • 1221 Transient Exciters
                          • 13 Control System
                            • 131 Components of a Shaker Controller
                              • 1311 Compressor
                              • 1312 Equalizer (Spectrum Shaper)
                              • 1313 Tracking Filter
                              • 1314 Excitation Controller (Amplitude Servo-Monitor)
                                • 132 Signal-Generating Equipment
                                  • 1321 Oscillators
                                  • 1322 Random Signal Generators
                                  • 1323 Tape Players
                                  • 1324 Data Processing
                                      • 14 Performance Specification
                                        • 141 Parameters for Performance Specification
                                          • 1411 Time-Domain Specifications
                                          • 1412 Frequency-Domain Specifications
                                            • 142 Linearity
                                            • 143 Instrument Ratings
                                              • 1431 Rating Parameters
                                                • 144 Accuracy and Precision
                                                  • 15 Motion Sensors and Transducers
                                                    • 151 Potentiometer
                                                      • 1511 Potentiometer Resolution
                                                      • 1512 Optical Potentiometer
                                                        • 152 Variable-Inductance Transducers
                                                          • 1521 Mutual-Induction Transducers
                                                          • 1522 Linear-Variable Differential Transformer
                                                          • 1523 Signal Conditioning
                                                            • 153 Mutual-Induction Proximity Sensor
                                                            • 154 Selfinduction Transducers
                                                            • 155 Permanent-Magnet Transducers
                                                            • 156 Alternating Current Permanent-Magnet Tachometer
                                                            • 157 Alternating Current Induction Tachometer
                                                            • 158 Eddy Current Transducers
                                                            • 159 Variable-Capacitance Transducers
                                                              • 1591 Capacitive Displacement Sensors
                                                              • 1592 Capacitive Angular Velocity Sensor
                                                              • 1593 Capacitance Bridge Circuit
                                                                • 1510 Piezoelectric Transducers
                                                                  • 15101 Sensitivity
                                                                  • 15102 Piezoelectric Accelerometer
                                                                  • 15103 Charge Amplifier
                                                                      • 16 Torque Force and Other Sensors
                                                                        • 161 Strain Gage Sensors
                                                                          • 1611 Equations for Strain Gage Measurements
                                                                          • 1612 Bridge Sensitivity
                                                                          • 1613 The Bridge Constant
                                                                          • 1614 The Calibration Constant
                                                                          • 1615 Data Acquisition
                                                                          • 1616 Accuracy Considerations
                                                                          • 1617 Semiconductor Strain Gages
                                                                          • 1618 Force and Torque Sensors
                                                                          • 1619 Strain Gage Torque Sensors
                                                                          • 16110 Deflection Torque Sensors
                                                                          • 16111 Variable-Reluctance Torque Sensor
                                                                          • 16112 Reaction Torque Sensors
                                                                            • 162 Miscellaneous Sensors
                                                                              • 1621 Stroboscope
                                                                              • 1622 Fiber Optic Sensors and Lasers
                                                                              • 1623 Fiber-Optic Gyroscope
                                                                              • 1624 Laser Doppler Interferometer
                                                                              • 1625 Ultrasonic Sensors
                                                                              • 1626 Gyroscopic Sensors
                                                                                  • References
                                                                                  • Appendix 1A Virtual Instrumentation for Data Acquisition Analysis and Presentation
                                                                                    • Summary
                                                                                    • List of Abbreviations
                                                                                    • 1A1 Dynamic Signals
                                                                                      • 1A11 Acquiring and Simulating Dynamic Signals
                                                                                        • 1A111 Aliasing
                                                                                        • 1A112 Time Continuity
                                                                                            • 1A2 Measurement Configuration Considerations
                                                                                              • 1A21 Input Signal Considerations
                                                                                                • 1A211 Input Pseudodifferential and Differential Configuration
                                                                                                • 1A212 Gain
                                                                                                • 1A213 Input Coupling
                                                                                                • 1A214 Integrated Electronic Piezoelectric Excitation
                                                                                                • 1A215 Nyquist Frequency and Bandwidth
                                                                                                • 1A216 Analog-to-Digital Conversion
                                                                                                • 1A217 Antialias Filters
                                                                                                • 1A218 Input Filter Delay
                                                                                                • 1A219 Overload Detection
                                                                                                  • 1A22 Output Signal Considerations
                                                                                                    • 1A221 Output Pseudodifferential and Differential Configuration
                                                                                                    • 1A222 Attenuation
                                                                                                    • 1A223 Digital-to-Analog Conversion
                                                                                                    • 1A224 Anti-imaging and Interpolation Filters
                                                                                                    • 1A225 Output Filter Delay
                                                                                                        • 1A3 Scaling and Calibration
                                                                                                          • 1A31 Scaling to Engineering Units
                                                                                                          • 1A32 Performing System Calibration
                                                                                                            • 1A321 Propagation Delay Calibration
                                                                                                                • 1A4 Limit Testing Analysis
                                                                                                                  • 1A41 Limit Testing Overview
                                                                                                                  • 1A42 Using the SVT Limit Testing VI
                                                                                                                    • 1A5 Integration
                                                                                                                      • 1A51 Introduction to Integration
                                                                                                                      • 1A52 Implementing Integration
                                                                                                                        • 1A521 Challenges when Integrating Vibration Data
                                                                                                                          • 1A53 Time-Domain Integration
                                                                                                                            • 1A531 Single-Shot Acquisition and Integration
                                                                                                                            • 1A532 Continuous Acquisition and Integration
                                                                                                                              • 1A54 Frequency-Domain Integration
                                                                                                                                • 1A6 Vibration-Level Measurements
                                                                                                                                  • 1A61 Measuring the Root Mean Square Level
                                                                                                                                    • 1A611 Single-Shot Buffered Acquisition
                                                                                                                                    • 1A612 Continuous Signal Acquisition
                                                                                                                                      • 1A62 Performing a Running RMS Level Measurement
                                                                                                                                      • 1A63 Computing the Peak Level
                                                                                                                                      • 1A64 Computing the Crest Factor
                                                                                                                                        • 1A7 Frequency Analysis
                                                                                                                                          • 1A71 FFT Fundamentals
                                                                                                                                            • 1A711 Number of Samples
                                                                                                                                            • 1A712 Frequency Resolution
                                                                                                                                            • 1A713 Maximum Resolvable Frequency
                                                                                                                                            • 1A714 Minimum Resolvable Frequency
                                                                                                                                            • 1A715 Number of Spectral Lines
                                                                                                                                            • 1A716 Relationship between Time-Domain and Frequency-Domain Specifications and Parameters
                                                                                                                                              • 1A72 Increasing Frequency Resolution
                                                                                                                                                • 1A721 Zoom FFT Analysis
                                                                                                                                                • 1A722 Frequency Resolution of the Zoom FFT VIs
                                                                                                                                                • 1A723 Zoom Measurement
                                                                                                                                                • 1A724 Zoom Settings
                                                                                                                                                • 1A725 Subset Analysis
                                                                                                                                                    • 1A8 Transient Analysis
                                                                                                                                                      • 1A81 Transient Analysis with the Sound and Vibration Toolkit
                                                                                                                                                      • 1A82 Performing an STFT vs Time
                                                                                                                                                        • 1A821 Selecting the FFT Block Size
                                                                                                                                                        • 1A822 Overlapping
                                                                                                                                                        • 1A823 Using the SVT STFT vs Time VI
                                                                                                                                                          • 1A83 Performing an STFT vs Rotational Speed
                                                                                                                                                            • 1A831 Converting the Pulse Train to Rotational Speed
                                                                                                                                                            • 1A832 STFT vs RPM
                                                                                                                                                              • 1A84 Measuring a Shock Response Spectrum
                                                                                                                                                                • 1A9 Waterfall Display
                                                                                                                                                                  • 1A91 Using the Display VIs
                                                                                                                                                                    • 1A911 Initializing the Display
                                                                                                                                                                    • 1A912 Sending Data to the Display
                                                                                                                                                                    • 1A913 Waterfall Display for Frequency Analysis
                                                                                                                                                                    • 1A914 Waterfall Display for Transient Analysis
                                                                                                                                                                    • 1A915 Waterfall Display for Octave Spectra
                                                                                                                                                                        • 1A10 Swept-Sine Measurements
                                                                                                                                                                          • 1A101 Swept-Sine Overview
                                                                                                                                                                          • 1A102 Choosing Swept-Sine vs FFT Measurements
                                                                                                                                                                          • 1A103 Taking a Swept-Sine Measurement
                                                                                                                                                                          • 1A104 Swept-Sine Measurement Example
                                                                                                                                                                              • Bibliography
                                                                                                                                                                              • Related Titles
                                                                                                                                                                                  • 53191ch2
                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                    • Chapter 2 Signal Conditioning and Modification
                                                                                                                                                                                      • Summary
                                                                                                                                                                                      • 21 Introduction
                                                                                                                                                                                      • 22 Amplifiers
                                                                                                                                                                                        • 221 Operational Amplifier
                                                                                                                                                                                        • 222 Use of Feedback in Opamp
                                                                                                                                                                                        • 223 Voltage Current and Power Amplifiers
                                                                                                                                                                                          • 2231 Charge Amplifiers
                                                                                                                                                                                            • 224 Instrumentation Amplifiers
                                                                                                                                                                                              • 2241 Differential Amplifier
                                                                                                                                                                                              • 2242 Common Mode
                                                                                                                                                                                                • 225 Amplifier Performance Ratings
                                                                                                                                                                                                  • 2251 Common-Mode Rejection Ratio
                                                                                                                                                                                                    • 226 Component Interconnection
                                                                                                                                                                                                      • 2261 Impedance Characteristics
                                                                                                                                                                                                      • 2262 Cascade Connection of Devices
                                                                                                                                                                                                      • 2263 AC-Coupled Ampliers
                                                                                                                                                                                                          • 23 Analog Filters
                                                                                                                                                                                                            • 231 Passive Filters and Active Filters
                                                                                                                                                                                                              • 2311 Number of Poles
                                                                                                                                                                                                                • 232 Low-Pass Filters
                                                                                                                                                                                                                  • 2321 Low-Pass Butterworth Filter
                                                                                                                                                                                                                    • 233 High-Pass Filters
                                                                                                                                                                                                                    • 234 Band-Pass Filters
                                                                                                                                                                                                                      • 2341 Resonance-Type Band-Pass Filters
                                                                                                                                                                                                                        • 235 Band-Reject Filters
                                                                                                                                                                                                                          • 24 Modulators and Demodulators
                                                                                                                                                                                                                            • 241 Amplitude Modulation
                                                                                                                                                                                                                              • 2411 Modulation Theorem
                                                                                                                                                                                                                              • 2412 Side Frequencies and Side Bands
                                                                                                                                                                                                                                • 242 Application of Amplitude Modulation
                                                                                                                                                                                                                                  • 2421 Fault Detection and Diagnosis
                                                                                                                                                                                                                                    • 243 Demodulation
                                                                                                                                                                                                                                      • 25 Analog ndashDigital Conversion
                                                                                                                                                                                                                                        • 251 Digital-to-Analog Conversion
                                                                                                                                                                                                                                          • 2511 DAC Error Sources
                                                                                                                                                                                                                                            • 252 Analog-to-Digital Conversion
                                                                                                                                                                                                                                            • 253 Analog-to-Digital Converter Performance Characteristics
                                                                                                                                                                                                                                              • 2531 Resolution and Quantization Error
                                                                                                                                                                                                                                              • 2532 Monotonicity Nonlinearity and Offset Error
                                                                                                                                                                                                                                              • 2533 Analog-to-Digital Converter Conversion Rate
                                                                                                                                                                                                                                                • 254 Sample-and-Hold Circuitry
                                                                                                                                                                                                                                                • 255 Digital Filters
                                                                                                                                                                                                                                                  • 2551 Software Implementation and Hardware Implementation
                                                                                                                                                                                                                                                      • 26 Bridge Circuits
                                                                                                                                                                                                                                                        • 261 Wheatstone Bridge
                                                                                                                                                                                                                                                        • 262 Constant-Current Bridge
                                                                                                                                                                                                                                                        • 263 Bridge Amplifiers
                                                                                                                                                                                                                                                          • 2631 Half-Bridge Circuits
                                                                                                                                                                                                                                                            • 264 Impedance Bridges
                                                                                                                                                                                                                                                              • 2641 Owen Bridge
                                                                                                                                                                                                                                                              • 2642 Wien-Bridge Oscillator
                                                                                                                                                                                                                                                                  • 27 Linearizing Devices
                                                                                                                                                                                                                                                                    • 271 Linearization by Software
                                                                                                                                                                                                                                                                    • 272 Linearization by Hardware Logic
                                                                                                                                                                                                                                                                    • 273 Analog Linearizing Circuitry
                                                                                                                                                                                                                                                                    • 274 Offsetting Circuitry
                                                                                                                                                                                                                                                                    • 275 Proportional-Output Circuitry
                                                                                                                                                                                                                                                                      • 2751 Curve-Shaping Circuitry
                                                                                                                                                                                                                                                                          • 28 Miscellaneous Signal Modification Circuitry
                                                                                                                                                                                                                                                                            • 281 Phase Shifters
                                                                                                                                                                                                                                                                            • 282 Voltage-to-Frequency Converter
                                                                                                                                                                                                                                                                            • 283 Frequency-to-Voltage Converter
                                                                                                                                                                                                                                                                            • 284 Voltage-to-Current Converters
                                                                                                                                                                                                                                                                            • 285 Peak-Hold Circuits
                                                                                                                                                                                                                                                                              • 29 Signal Analyzers and Display Devices
                                                                                                                                                                                                                                                                                • 291 Signal Analyzers
                                                                                                                                                                                                                                                                                • 292 Oscilloscopes
                                                                                                                                                                                                                                                                                  • 2921 Triggering
                                                                                                                                                                                                                                                                                  • 2922 Lissajous Patterns
                                                                                                                                                                                                                                                                                  • 2923 Digital Oscilloscopes
                                                                                                                                                                                                                                                                                      • Bibliography
                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                          • 53191ch3
                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                            • Chapter 3 Vibration Testing
                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                              • 31 Introduction
                                                                                                                                                                                                                                                                                              • 32 Representation of a Vibration Environment
                                                                                                                                                                                                                                                                                                • 321 Test Signals
                                                                                                                                                                                                                                                                                                  • 3211 Stochastic vs Deterministic Signals
                                                                                                                                                                                                                                                                                                    • 322 Deterministic Signal Representation
                                                                                                                                                                                                                                                                                                      • 3221 Single-Frequency Signals
                                                                                                                                                                                                                                                                                                      • 3222 Sine Sweep
                                                                                                                                                                                                                                                                                                      • 3223 Sine Dwell
                                                                                                                                                                                                                                                                                                      • 3224 Decaying Sine
                                                                                                                                                                                                                                                                                                      • 3225 Sine Beat
                                                                                                                                                                                                                                                                                                      • 3226 Sine Beat with Pauses
                                                                                                                                                                                                                                                                                                      • 3227 Multifrequency Signals
                                                                                                                                                                                                                                                                                                      • 3228 Actual Excitation Records
                                                                                                                                                                                                                                                                                                      • 3229 Simulated Excitation Signals
                                                                                                                                                                                                                                                                                                        • 323 Stochastic Signal Representation
                                                                                                                                                                                                                                                                                                          • 3231 Ergodic Random Signals
                                                                                                                                                                                                                                                                                                          • 3232 Stationary Random Signals
                                                                                                                                                                                                                                                                                                          • 3233 Independent and Uncorrelated Signals
                                                                                                                                                                                                                                                                                                          • 3234 Transmission of Random Excitations
                                                                                                                                                                                                                                                                                                            • 324 Frequency-Domain Representations
                                                                                                                                                                                                                                                                                                              • 3241 Fourier Spectrum Method
                                                                                                                                                                                                                                                                                                              • 3242 Power Spectral Density Method
                                                                                                                                                                                                                                                                                                                • 325 Response Spectrum
                                                                                                                                                                                                                                                                                                                  • 3251 Displacement Velocity and Acceleration Spectra
                                                                                                                                                                                                                                                                                                                  • 3252 Response-Spectra Plotting Paper
                                                                                                                                                                                                                                                                                                                  • 3253 Zero-Period Acceleration
                                                                                                                                                                                                                                                                                                                  • 3254 Uses of Response Spectra
                                                                                                                                                                                                                                                                                                                    • 326 Comparison of Various Representations
                                                                                                                                                                                                                                                                                                                      • 33 Pretest Procedures
                                                                                                                                                                                                                                                                                                                        • 331 Purpose of Testing
                                                                                                                                                                                                                                                                                                                        • 332 Service Functions
                                                                                                                                                                                                                                                                                                                          • 3321 Active Equipment
                                                                                                                                                                                                                                                                                                                          • 3322 Passive Equipment
                                                                                                                                                                                                                                                                                                                          • 3323 Functional Testing
                                                                                                                                                                                                                                                                                                                            • 333 Information Acquisition
                                                                                                                                                                                                                                                                                                                              • 3331 Interface Details
                                                                                                                                                                                                                                                                                                                              • 3332 Effect of Neglecting Interface Dynamics
                                                                                                                                                                                                                                                                                                                              • 3333 Effects of Damping
                                                                                                                                                                                                                                                                                                                              • 3334 Effects of Inertia
                                                                                                                                                                                                                                                                                                                              • 3335 Effect of Natural Frequency
                                                                                                                                                                                                                                                                                                                              • 3336 Effect of Excitation Frequency
                                                                                                                                                                                                                                                                                                                              • 3337 Other Effects of Interface
                                                                                                                                                                                                                                                                                                                                • 334 Test-Program Planning
                                                                                                                                                                                                                                                                                                                                  • 3341 Testing of Cabinet-Mounted Equipment
                                                                                                                                                                                                                                                                                                                                    • 335 Pretest Inspection
                                                                                                                                                                                                                                                                                                                                      • 34 Testing Procedures
                                                                                                                                                                                                                                                                                                                                        • 341 Resonance Search
                                                                                                                                                                                                                                                                                                                                        • 342 Methods of Determining Frequency-Response Functions
                                                                                                                                                                                                                                                                                                                                          • 3421 Fourier Transform Method
                                                                                                                                                                                                                                                                                                                                          • 3422 Spectral Density Method
                                                                                                                                                                                                                                                                                                                                          • 3423 Harmonic Excitation Method
                                                                                                                                                                                                                                                                                                                                            • 343 Resonance-Search Test Methods
                                                                                                                                                                                                                                                                                                                                              • 3431 Hammer (Bump) Test and Drop Test
                                                                                                                                                                                                                                                                                                                                              • 3432 Pluck Test
                                                                                                                                                                                                                                                                                                                                              • 3433 Shaker Tests
                                                                                                                                                                                                                                                                                                                                                • 344 Mechanical Aging
                                                                                                                                                                                                                                                                                                                                                  • 3441 Equivalence for Mechanical Aging
                                                                                                                                                                                                                                                                                                                                                  • 3442 Excitation-Intensity Equivalence
                                                                                                                                                                                                                                                                                                                                                  • 3443 Dynamic-Excitation Equivalence
                                                                                                                                                                                                                                                                                                                                                  • 3444 Cumulative Damage Theory
                                                                                                                                                                                                                                                                                                                                                    • 345 Test-Response Spectrum Generation
                                                                                                                                                                                                                                                                                                                                                    • 346 Instrument Calibration
                                                                                                                                                                                                                                                                                                                                                    • 347 Test-Object Mounting
                                                                                                                                                                                                                                                                                                                                                    • 348 Test-Input Considerations
                                                                                                                                                                                                                                                                                                                                                      • 3481 Test Nomenclature
                                                                                                                                                                                                                                                                                                                                                      • 3482 Testing with Uncorrelated Excitations
                                                                                                                                                                                                                                                                                                                                                      • 3483 Symmetrical Rectilinear Testing
                                                                                                                                                                                                                                                                                                                                                      • 3484 Geometry vs Dynamics
                                                                                                                                                                                                                                                                                                                                                      • 3485 Some Limitations
                                                                                                                                                                                                                                                                                                                                                      • 3486 Testing Black Boxes
                                                                                                                                                                                                                                                                                                                                                      • 3487 Phasing of Excitations
                                                                                                                                                                                                                                                                                                                                                      • 3488 Testing a Gray or White Box
                                                                                                                                                                                                                                                                                                                                                      • 3489 Overtesting in Multitest Sequences
                                                                                                                                                                                                                                                                                                                                                          • 35 Some Practical Information
                                                                                                                                                                                                                                                                                                                                                            • 351 Random Vibration Test Example
                                                                                                                                                                                                                                                                                                                                                            • 352 Vibration Shakers and Control Systems
                                                                                                                                                                                                                                                                                                                                                              • Bibliography
                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                  • 53191ch4
                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                    • Chapter 4 Experimental Modal Analysis
                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                      • 41 Introduction
                                                                                                                                                                                                                                                                                                                                                                      • 42 Frequency-Domain Formulation
                                                                                                                                                                                                                                                                                                                                                                        • 421 Transfer-Function Matrix
                                                                                                                                                                                                                                                                                                                                                                        • 422 Principle of Reciprocity
                                                                                                                                                                                                                                                                                                                                                                          • 43 Experimental Model Development
                                                                                                                                                                                                                                                                                                                                                                            • 431 Extraction of the Time-Domain Model
                                                                                                                                                                                                                                                                                                                                                                              • 44 Curve Fitting of Transfer Functions
                                                                                                                                                                                                                                                                                                                                                                                • 441 Problem Identification
                                                                                                                                                                                                                                                                                                                                                                                • 442 Single- and Multi-Degree-of-Freedom Techniques
                                                                                                                                                                                                                                                                                                                                                                                • 443 Single-Degree-of-Freedom Parameter Extraction in the Frequency Domain
                                                                                                                                                                                                                                                                                                                                                                                  • 4431 Circle-Fit Method
                                                                                                                                                                                                                                                                                                                                                                                    • Case of Viscous Damping
                                                                                                                                                                                                                                                                                                                                                                                    • Case of Hysteretic Damping
                                                                                                                                                                                                                                                                                                                                                                                      • 4432 Peak-Picking Method
                                                                                                                                                                                                                                                                                                                                                                                        • 444 Multi-Degree of Freedom Curve Fitting
                                                                                                                                                                                                                                                                                                                                                                                          • 4441 Formulation of the Method
                                                                                                                                                                                                                                                                                                                                                                                            • 445 A Comment on Static Modes and Rigid-Body Modes
                                                                                                                                                                                                                                                                                                                                                                                            • 446 Residue Extraction
                                                                                                                                                                                                                                                                                                                                                                                              • 45 Laboratory Experiments
                                                                                                                                                                                                                                                                                                                                                                                                • 451 Lumped-Parameter System
                                                                                                                                                                                                                                                                                                                                                                                                  • 4511 Frequency-Domain Test
                                                                                                                                                                                                                                                                                                                                                                                                  • 4512 Time-Domain Tests
                                                                                                                                                                                                                                                                                                                                                                                                    • 452 Distributed-Parameter System
                                                                                                                                                                                                                                                                                                                                                                                                      • 46 Commercial EMA Systems
                                                                                                                                                                                                                                                                                                                                                                                                        • 461 System Configuration
                                                                                                                                                                                                                                                                                                                                                                                                          • 4611 FFT Analysis Options
                                                                                                                                                                                                                                                                                                                                                                                                          • 4612 Modal Analysis Components
                                                                                                                                                                                                                                                                                                                                                                                                              • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                  • 53191ch5
                                                                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                    • Chapter 5 Mechanical Shock
                                                                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                      • 51 Definitions
                                                                                                                                                                                                                                                                                                                                                                                                                        • 511 Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 512 Simple (or Perfect) Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 513 Half-Sine Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 514 Versed-Sine (or Haversine) Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 515 Terminal Peak Sawtooth Shock or Final Peak Sawtooth Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 516 Rectangular Shock
                                                                                                                                                                                                                                                                                                                                                                                                                          • 5161 Trapezoidal Shock
                                                                                                                                                                                                                                                                                                                                                                                                                              • 52 Description in the Time Domain
                                                                                                                                                                                                                                                                                                                                                                                                                              • 53 Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                • 531 Need
                                                                                                                                                                                                                                                                                                                                                                                                                                • 532 Shock Response Spectrum Definition
                                                                                                                                                                                                                                                                                                                                                                                                                                • 533 Response of a Linear One-Degree-of-Freedom System
                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5331 Shock Defined by a Force
                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5332 Shock Defined by an Acceleration
                                                                                                                                                                                                                                                                                                                                                                                                                                    • 534 Definitions
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5341 Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5342 Absolute Acceleration Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5343 Relative Displacement Shock Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5344 Primary Positive Shock Response Spectrum or Initial Positive Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5345 Primary (or Initial) Negative Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5346 Secondary (or Residual) Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5347 Positive (or Maximum Positive) Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5348 Negative (or Maximum Negative) Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5349 Maximax Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53410 Choice of Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                        • 535 Standardized Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5351 Definition
                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5352 Standardized Shock Response Spectra of Simple Shocks
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53521 Half-Sine Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53522 Versed Sine Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53523 Terminal Peak Sawtooth Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53524 Rectangular Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53525 Trapezoidal Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 536 Choice of Damping
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 537 Shock Response Spectra Domains
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 538 Algorithms for Calculation of the Shock Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 539 Choice of the Digitization Frequency of the Signal
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5310 Use of Shock Response Spectra for the Study of Systems with Several Degrees of Freedom
                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 54 Pyroshocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 55 Use of Shock Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 551 Severity Comparison of Several Shocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 552 Test Specification Development from Real Environment Data
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5521 Synthesis of Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5522 Nature of the Specification
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5523 Choice of Shape
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5524 Amplitude
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5525 Duration
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5526 Difficulties
                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 56 Standards
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 561 Types of Standards
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 562 Installation Conditions of Test Item
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 563 Uncertainty Factor
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 564 Bump Test
                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 57 Damage Boundary Curve
                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 571 Definition
                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 572 Analysis of Test Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 58 Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 581 Main Types
                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 582 Impact Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5821 Universal Shock-Test Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 58211 Impact Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 58212 Impulse Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 583 Shock Simulators (Programmers)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5831 Half-Sine Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58311 Shock Duration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58312 Impact Velocity
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58313 Maximum Deformation of the Shock Simulator (Programmer)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58314 Shock Amplitude
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58315 Characteristics of the Target
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5832 Terminal Peak Sawtooth Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5833 Rectangular Pulse ndash Trapezoidal Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5834 Universal Shock Simulator (Programmer)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 58341 Generating a Half-Sine Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 58342 Generating a Terminal Peak Sawtooth Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 58343 Trapezoidal Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 584 Limitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5841 Limitations of the Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5842 Limitations of Shock Simulators
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 585 Pneumatic Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 586 High Impact Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5861 Lightweight High Impact Shock Machine
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5862 Medium Weight High Impact Shock Machine
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 587 Specific Test Facilities
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 59 Generation of Shock Using Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 591 Principle Behind the Generation of a Simple Shape Signal versus Time
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 592 Main Advantages
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 593 Pre- and Postshocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5931 Requirements
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5932 Solutions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 59321 Optimized Pre- and Postpulses
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5933 Incidence on the Shock Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 594 Limitations of Electrodynamic Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5941 Mechanical Limitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 59411 Abacuses
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5942 Electronic Limitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 595 The Use of Electrohydraulic Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 510 Control by a Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 5101 Principle
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 5102 Principal Shapes of Elementary Signals
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 51021 Decaying Sinusoid
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 51022 ZERD Function
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 51023 WAVSIN Waveform
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 5103 Comparison of WAVSIN SHOC Waveforms and Decaying Sinusoid
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 5104 Criticism of Control by a Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 511 Pyrotechnic Shock Simulation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5111 Simulation Using Pyrotechnic Facilities
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5112 Simulation Using Metal-to-Metal Impact
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5113 Simulation Using Electrodynamic Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5114 Simulation Using Conventional Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53191ch6
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Chapter 6 Machine Condition Monitoring and Fault Diagnostics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 61 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 62 Machinery Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 621 Causes of Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 622 Types of Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 623 Frequency of Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 63 Basic Maintenance Strategies
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 631 Run-to-Failure (Breakdown) Maintenance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 632 Scheduled (Preventative) Maintenance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 633 Condition-Based (Predictive Proactive Reliability Centered On-Condition) Maintenance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 64 Factors Which Influence Maintenance Strategy
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 65 Machine Condition Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 651 Periodic Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 652 Continuous Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 66 Transducer Selection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 661 Noncontact Displacement Transducers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 662 Velocity Transducers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 663 Acceleration Transducers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 67 Transducer Location
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 68 Recording and Analysis Instrumentation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 681 Vibration Meters
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 682 Data Collectors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 683 Frequency-Domain Analyzers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 684 Time-Domain Instruments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 685 Tracking Analyzers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 69 Display Formats and Analysis Tools
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 691 Time Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6911 Time-Waveform Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6912 Time-Waveform Indices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6913 Time-Synchronous Averaging
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6914 Negative Averaging
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6915 Orbits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6916 Probability Density Functions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6917 Probability Density Moments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 692 Frequency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6921 Band-Pass Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6922 Shock Pulse (Spike Energy)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6923 Enveloped Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6924 Signature Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6925 Cascades (Waterfall Plots)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6926 Masks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6927 Frequency-Domain Indices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 693 Modal Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 694 Quefrency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 610 Fault Detection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 6101 Standards
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61011 Standards Based on Machinery Type
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61012 Standards Based on Vibration Severity
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 6102 Acceptance Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 61021 Statistical Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 6103 Frequency-Domain Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61031 Limited Band Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61032 Constant Bandwidth Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61033 Constant Percentage Bandwidth Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 611 Fault Diagnostics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 6111 Forcing Functions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61111 Unbalance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61112 Misalignment
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61113 Mechanical Looseness
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61114 Soft Foot
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61115 Rubs
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61116 Resonances
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61117 Oil Whirl
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61118 Oil Whip
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61119 Structural Vibrations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 611110 Foundation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 6112 Specific Machine Components
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 61121 Damaged or Worn Rolling-Element Bearings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 61122 Damaged or Worn Gears
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 6113 Specific Machine Types
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61131 Pumps
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61132 Fans
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61133 Electric Motors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61134 Steam and Gas Turbines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61135 Compressors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61136 Reciprocating Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 6114 Advanced Fault Diagnostic Techniques
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 53191ch7
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • Chapter 7 Vibration-Based Tool Condition Monitoring Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 71 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 72 Mechanics of Turning
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 721 General Terms
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 722 Chatter Vibrations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 723 Tool Wear
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7231 Tool Failure Mechanisms
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7232 Tool Failure Modes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7233 Tool Wear Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7234 Tool Wear Stages
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 73 Vibration Signal Recording
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 731 Direct and Indirect Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 732 Sensor Requirements for Tool Wear Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 733 Force Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7331 Direct Measurement Dynamometers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7332 Indirect Force Sensors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7333 Piezoelectric Strain Sensors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7334 Resistance Strain Gauges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7335 Customized Force Sensors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 734 Acceleration Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 735 Acoustic Emission Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 736 Sensor Comparisons
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 74 Signal Processing for Sensor-Based Tool Condition Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 741 Feature Extraction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7411 Time Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7412 Frequency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7413 Statistical Processing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7414 TimendashFrequency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 742 Feature Selection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 75 Wear ModelDecision-Making for Sensor-Based Tool Condition Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 751 Trending Threshold
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 752 Neural Networks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7521 Unsupervised Networks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7522 Supervised Networks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 753 Fuzzy Logic
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 754 Other Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 76 Conclusion
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53191ch8
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Chapter 8 Fault Diagnosis of Helicopter Gearboxes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 81 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 82 Abnormality Scaling
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 83 The Structure-Based Connectionist Network
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 84 Sensor Location Selection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 841 Coverage Index
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 842 Overlap Index
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 843 Monitoring Effectiveness
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 85 A Case Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 851 Structural and Featural Influences
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 852 Evaluation of Influences
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 853 Fault Detection Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 854 Fault Diagnostic Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 8541 Faulty Subsystem Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 8542 Faulty Component Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 855 Sensor Location Evaluation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 856 Sensor Location Validation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 86 Conclusion
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 53191ch9
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Chapter 9 Vibration Suppression and Monitoring in Precision Motion Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 91 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 92 Mechanical Design to Minimize Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 921 Stability and Static Determinacy of Machine Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 922 Two-Dimensional Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 923 Three-Dimensional Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 93 Adaptive Notch Filter
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 931 Fast Fourier Transform
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 932 Simulation and Experiments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 94 Real-Time Vibration Analyzer
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 941 Learning Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 942 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 943 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 944 Experiments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 9441 Input Variables mdash the Evaluation Criteria
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 94411 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 94412 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 9442 Evaluation Rules
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 94421 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 94422 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 9443 Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 94431 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 94432 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 95 Practical Insights and Case Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 96 Conclusions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 53191ch10
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Chapter 10 Vibration and Shock Problems of Civil Engineering Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 101 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 102 Earthquake-Induced Vibration of Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1021 Seismicity and Ground Motions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1022 Influence of Local Site Conditions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1023 Response of Structures to Ground Motions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1024 Dynamic Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10241 Equations of Motion for Linear Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10242 Equations of Motion for Linear Multiple-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1025 Earthquake Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10251 Elastic Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10252 Smoothed Design Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10253 Ductility-Modified Response Spectrum Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1026 Design Philosophy and the Code Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10261 Performance-Based Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1027 Analysis Options for Earthquake Effects
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10271 Dynamic Time History Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10272 Response Spectrum Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 102721 Response Spectrum Analysis of Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 102722 Response Spectrum Analysis of Multi-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10273 Equivalent Static Analysis (Force-Based Approach)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10274 Displacement-Based Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1028 SoilndashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1029 Active and Passive Control Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 10210 Worked Examples
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 103 Dynamic Effects of Wind Loading on Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1031 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1032 Wind Speed
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1033 Design Structures for Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10331 Types of Wind Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10332 Design Criteria
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10333 Static Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1034 Along and Across-Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10341 Along-Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10342 Across-Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1035 Wind Tunnel Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1036 Comfort Criteria Human Response to Building Motion
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1037 Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1038 Comparison with Earthquake Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 104 Vibrations Due to Fluid ndashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1041 Added Mass and Inertial Coupling
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1042 Wave-Induced Vibration of Structure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 105 Blast Loading and Blast Effects on Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1051 Explosions and Blast Phenomenon
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1052 Explosive Air-Blast Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10521 Blast Wave Scaling Laws
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10522 Prediction of Blast Pressure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1053 Gas Explosion Loading and Effect of Internal Explosions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1054 Structural Response to Blast Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10541 Elastic Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10542 Elasto-Plastic Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1055 Material Behaviors at High Strain Rate
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10551 Dynamic Properties of Concrete under High Strain Rates
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10552 Dynamic Properties of Reinforcing Steel under High Strain Rates
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1056 Failure Modes of Blast-Loaded Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10561 Global Structural Behavior
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10562 Localized Structural Behavior
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10563 PressurendashImpulse ( PndashI ) Diagrams
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1057 Blast WavendashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1058 Effect of Ground Shocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10581 Loads from Air-Induced Ground Shock
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10582 Loads from Direct Ground Shock
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1059 Technical Design Manuals for Blast-Resistant Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 10510 Computer Programs for Blast and Shock Effects
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 106 Impact Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1061 Structural Impact between Two Bodies mdash Hard Impact and Soft Impact
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1062 Example mdash Aircraft Impact
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 107 Floor Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1071 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1072 Types of Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10721 Walking
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10722 Rhythmic Activities
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10723 Mechanical Equipment
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10724 Analysis Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1073 Natural Frequency of Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10731 Computing the Natural Frequency
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10732 Computing Deflection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10733 Damping
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10734 Resonance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1074 Vibration Caused by Walking
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10741 Minimum Natural Frequency
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1075 Design for Rhythmic Excitation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10751 Harmonics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10752 Minimum Natural Frequency
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1076 Example mdash Vibration Analysis of a Reinforced Concrete Floor
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 53191ch11
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Chapter 11 Seismic Base Isolation and Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 111 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1111 From Ductility Design to Base Isolation and Control Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1112 The Importance of Reducing Seismic Input and Response
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 112 Seismic Base Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1121 Historical Development of Base Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1122 Basic Principle
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1123 Issues in Seismic Base Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11231 Performance Criteria
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11232 Type of Structure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11233 Site Characteristics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11234 Retrofit Issues
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11235 Design of Building Services
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11236 Expected Life of Isolator
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1124 Seismic Isolation Devices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11241 Laminated Rubber Bearings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11242 Lead Rubber Bearing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11243 Friction-Based Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11244 Other Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1125 Design of Isolation Devices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11251 High-Damping Rubber Bearing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112511 Stability against Buckling
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112512 Stability against Roll Out
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11252 Lead Rubber Bearings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112521 Design of Lead Plug
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112522 Design of Laminated Rubber Bearing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11253 Design of Friction Pendulum System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1126 Verification of Properties of Isolation Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11261 Tests for Isolation Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 112611 System Characterization Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 112612 Prototype Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 112613 Quality Control Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11262 Uniform Building Code Recommendations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112621 Units Dependent on Loading Rates
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112622 Units Dependent on Bilateral Load
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112623 System Adequacy
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1127 Analysis of Base-Isolated Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11271 Modeling of a Superstructure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11272 Modeling of Isolation System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11273 Static Analysis Procedure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11274 Dynamic Analysis Procedure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 112741 Response Spectrum Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 112742 Time-History Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11275 Software for Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1128 Experimental Methods for Isolated Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1129 Implementation of Seismic Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11291 New Construction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112911 Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112912 Bridges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11292 Seismic Retrofit
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112921 Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112922 Bridges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11293 Other Implementations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 11210 Performance during Past Earthquakes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 112101 Performance of Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 112102 Performance of Bridges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 113 Seismic Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1131 Historical Development of Seismic Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1132 Basic Principles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11321 Passive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11322 Active Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11323 Semiactive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11324 Hybrid Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11325 Categorization of Basic Principles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1133 Important Issues in Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11331 SoilndashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11332 DevicendashStructure Interaction and Time Delay
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11333 Design Guidelines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1134 Vibration-Control Devices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11341 Passive Control Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113411 Metallic Yielding Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113412 Friction Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113413 Viscoelastic Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113414 Viscous Fluid Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113415 Tuned Mass Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11342 Active Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113421 Electromagnetic Actuator
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113422 Hydraulic Actuators
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11343 Semiactive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113431 Variable-Orifice Hydraulic Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113432 Controllable Fluid Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113433 Controllable Friction Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11344 Hybrid Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1135 Control Algorithm
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11351 Active Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11352 Semiactive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113521 Common Control Schemes for Controllable Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113522 Special Control Schemes for Controllable Damper
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1136 Experimental Performance Verification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11361 Shaking Table Tests of a Flexible Structural Model with TMD AMD and ATMD
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11362 Substructure Hybrid Test
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113621 Hybrid Tests Using Hydraulic Actuator
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113622 Hybrid Tests Using Shaking Table
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113623 Hybrid Tests Using Inertia-Force-Driven Loading System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1137 Implementations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11371 Semiactive Control of Full-Scale Structures Using Variable Joint Damper System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113711 Background of Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113712 Test System Set Up
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113713 Control Algorithm
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113714 Test Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11372 Application of Structural Control Technologies to Seismic Retrofit of a Cable-Stayed Bridge
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113721 Background of Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113722 Basic Concept of Seismic Retrofit
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113723 Modal Shape Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113724 Time-History Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113725 Soil ndash Structure Interaction Effect
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113726 Semiactive Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53191ch12
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Chapter 12 Seismic Random Vibration of Long-Span Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 121 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1211 Basic Concepts of Random Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12111 Stationary Random Process
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12112 Nonstationary Random Process
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1212 Three Methods for Structural Seismic Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12121 Response Spectrum Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12122 Time-History Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12123 Random Vibration Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 121231 Davenport Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 121232 Vanmarcke Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 12124 Comparisons of the Three Seismic-Analysis Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 122 Seismic Random-Excitation Fields
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1221 Power Spectral Density of Spatially Varying Ground Acceleration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1222 Several Coherence Models
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12221 FengndashHu Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12222 Harichandran ndashVanmarcke Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12223 LohndashYeh Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12224 OliveirandashHaondashPenzien Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12225 LucondashWong Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12226 QundashWangndashWang Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1223 Generation of Ground Acceleration Power Spectral Density Curves from Acceleration Response Spectrum Curves
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12231 Kaul Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12232 Iteration Scheme
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1224 Seismic Equations of Motion of Long-Span Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1225 Seismic Waves and Their Geometrical Expressions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 123 Pseudoexcitation Method for Structural Random Vibration Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1231 Structures Subjected to Stationary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12311 Single Stationary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12312 Multiple Stationary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1232 Structures Subjected to Nonstationary Random Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12321 Structures Subjected to Uniformly Modulated Evolutionary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 123211 Single Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 123212 Multiple Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12322 Structures Subjected to Nonuniformly Modulated Evolutionary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 123221 Single Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 123222 Multiple Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1233 Precise Integration Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12331 Precise Integration of Exponential Matrices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12332 Particular Solutions and Precise Integration Formulas for Various Forms of Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 123321 Linear Loading Form (HPD-L Form)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 123322 Sinusoidal Loading Form (HPD-S Form)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 123323 Exponentially Decaying Sinusoidal Loading Form (HPD-E Form)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 124 Long-Span Structures Subjected to Stationary Random Ground Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1241 The Solution of Equations of Motion Using the Pseudoexcitation Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1242 Numerical Comparisons with Other Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12421 Song-Hua-Jiang Suspension Bridge
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 124211 All Supports Move Uniformly
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 124212 Wave Passage Effect Is Taken into Account
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 124213 Wave-Passage Effect and Incoherence Effect Are Jointly Taken into Account
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 12422 San Joaquin Concrete Bridge
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 125 Long-Span Structures Subjected to Nonstationary Random Ground Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1251 Modulation Functions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1252 The Formulas for Nonstationary Multiexcitation Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1253 Expected Extreme Values of Nonstationary Random Processes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1254 Numerical Comparisons with the Corresponding Stationary Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 126 Conclusions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 53191ch13
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Chapter 13 Seismic Qualification of Equipment
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 131 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 132 Distribution Qualification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1321 Drive-Signal Generation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1322 Distribution Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1323 Test Procedures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 133 Seismic Qualification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1331 Stages of Seismic Qualification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1332 Test Preliminaries
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1333 Single-Frequency Testing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1334 Multifrequency Testing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1335 Generation of RRS Specifications
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 53191ch14
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Chapter 14 Human Response to Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 141 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 142 Vibration Excitations on Humans
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1421 Excitation Characteristics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 143 Human Response to Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1431 Vibration Perception
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1432 Frequency Weighting Curve
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1433 Iso-Perception Curves
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1434 Detection Threshold Curve
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 144 Regulation of Human Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1441 Acceptable Vibration Levels in Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1442 Whole-Body Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1443 HandndashArm Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
Page 16: Vibration Monitoring, Testing, and Instrumentationpreview.kingborn.net › 646000 › d1a74678d91943e5ba1d5e... · The MEMS Handbook, Second Edition MEMS: Introduction and Fundamentals

If the velocity amplitude is denoted by v and the acceleration amplitude by a it follows from Equation

12 and Equation 13 thatv frac14 vs eth14THORN

and

a frac14 vv eth15THORN

Box 11

VIBRATION INSTRUMENTATION

Vibration Testing Applications for Products

Design and Development Production Screening and Quality Assessment Utilization and Qualification for Special Applications

Testing Instrumentation

Exciter (excites the test object) Controller (controls the exciter for accurate excitation) Sensors and Transducers (measure excitations and responses and provide excitation error

signals to controller) Signal Conditioning (converts signals to appropriate form) Recording and Display (perform processing storage and documentation)

Exciters

Shakers

1 Electrodynamic (high bandwidth moderate power complex and multifrequency

excitations)

2 Hydraulic (moderate to high bandwidth high power complex and multifrequency

excitations)

3 Inertial (low bandwidth low power single-frequency harmonic excitations)

TransientInitial Condition

1 Hammers (impulsive bump tests)

2 Cable Release (step excitations)

3 Drop (impulsive)

Signal Conditioning

Filters Amplifiers Amplifiers ModulatorsDemodulators ADCDAC

Sensors

Motion (displacement velocity acceleration) Force (strain torque)

Vibration Monitoring Testing and Instrumentation1-4

53191mdash522007mdash1201mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

TABLE 11 Typical Operation-Capability Ranges for Various Shaker Types

Shaker Type Typical Operational Capabilities

Frequency Maximum Displacement

(Stroke)

Maximum

Velocity

Maximum

Acceleration

Maximum

Force

Excitation

Waveform

Hydraulic

(electrohydraulic)

Low

(01ndash500 Hz)

High (20 in 50 cm) Intermediate

(50 insec

125 cmsec)

Intermediate

(20 g)

High (100000 lbf

450000 N)

Average flexibility (simple

to complex and random)

Inertial

(counter-rotating mass)

Intermediate

(2ndash50 Hz)

Low (1 in 25 cm) Intermediate

(50 insec

125 cmsec)

Intermediate

(20 g)

Intermediate

(1000 lbf 4500 N)

Sinusoidal only

Electromagnetic

(electrodynamic)

High

(2ndash10000 Hz)

Low (1 in 25 cm) Intermediate

(50 insec

125 cmsec)

High (100 g) Low to intermediate

(450 lbf 2000 N)

High flexibility and accuracy

(simple to complex and

random)

VibrationInstru

mentation

1-5

53191mdash522007mdash

1201mdashSENTHILKUMARmdash246494mdash

CRCndashpp1ndash112

copy 2007 by Taylor amp Francis Group LLC

An idealized performance curve of a shaker

has a constant displacementndashamplitude region a

constant velocityndashamplitude region and a con-

stant accelerationndashamplitude region for low

intermediate and high frequencies respectively

in the operating frequency range Such an ideal

performance curve is shown in Figure 13(a) on a

frequencyndashvelocity plane Logarithmic axes are

used In practice typical shaker performance

curves would be fairly smooth yet nonlinear

curves similar to those shown in Figure 13(b)

As the mass increases the performance curve

compresses Note that the acceleration limit of a

shaker depends on the mass of the test object

(load) Full load corresponds to the heaviest object

that could be tested The ldquono loadrdquo condition

corresponds to a shaker without a test object To

standardize the performance curves they are

usually defined at the rated load of the shaker A

performance curve in the frequencyndashvelocity

plane may be converted to a curve in the

frequencyndashacceleration plane simply by increasing

the slope of the curve by a unit magnitude (ie

20 dbdecade)

Several general observations can be made from

Equation 14 and Equation 15 In the constant-

peak displacement region of the performance

curve the peak velocity increases proportionally

with the excitation frequency and the peak

acceleration increases with the square of the excitation frequency In the constant-peak velocity region

the peak displacement varies inversely with the excitation frequency and the peak acceleration increases

proportionately In the constant-peak acceleration region the peak displacement varies inversely with the

square of the excitation frequency and the peak velocity varies inversely with the excitation frequency

This further explains why rated stroke maximum velocity and maximum acceleration values are not

simultaneously realized

121 Shaker Selection

Vibration testing is accomplished by applying a specified excitation to the test package using a shaker

apparatus and monitoring the response of the test object Test excitation may be represented by its

response spectrum The test requires that the response spectrum of the actual excitation known as the

test response spectrum (TRS) envelops the response spectrum specified for the particular test known as

the required response spectrum (RRS)

A major step in the planning of any vibration testing program is the selection of a proper shaker

(exciter) system for a given test package The three specifications that are of primary importance in

selecting a shaker are the force rating the power rating and the stroke (maximum displacement) rating

Force and power ratings are particularly useful in moderate to high frequency excitations and the stroke

rating is the determining factor for low frequency excitations In this section a procedure is given to

determine conservative estimates for these parameters in a specified test for a given test package

Frequency domain considerations are used here

Stroke

Limit M

ax

Acceleration

MaxVelocity

Peak

Vel

ocity

(cm

s)

01 1 10 100

FullLoad

NoLoad

Frequency (Hz)(a)

Peak

Vel

ocity

(cm

s)

100

10

1

100

10

1

01 1 10 100

FullLoad

NoLoad

Frequency (Hz)(b)

FIGURE 13 Performance curve of a vibration exciter

in the frequencyndashvelocity plane (log) (a) ideal (b)

typical

Vibration Monitoring Testing and Instrumentation1-6

53191mdash522007mdash1201mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

1211 Force Rating

In the frequency domain the (complex) force at the exciter (shaker) head is given by

F frac14 mHethvTHORNasethvTHORN eth16THORNin which v is the excitation frequency variable m is the total mass of the test package including

mounting fixture and attachments asethvTHORN is the Fourier spectrum of the support-location (exciter head)

acceleration and H(v) is frequency response function that takes into account the flexibility and

damping effects (dynamics) of the test package apart from its inertia In the simplified case where the

test package can be represented by a simple oscillator of natural frequency vn and damping ratio by zt

this function becomes

HethvTHORN frac14 1thorn 2jztv=vn=12 ethv=vnTHORN2 thorn 2jztv=vn eth17THORNin which j frac14 ffiffiffiffi

21p

This approximation is adequate for most practical purposes The static weight of the

test object is not included in Equation 16 Most heavy-duty shakers which are typically hydraulic

have static load support systems such as pneumatic cushion arrangements that can exactly balance the

dead load The exciter provides only the dynamic force In cases where shaker directly supports the

gravity load in the vertical test configuration Equation 16 should be modified by adding a term to

represent this weight

A common practice in vibration test applications is to specify the excitation signal by its response

spectrum This is simply the peak response of a simple oscillator expressed as a function of its natural

frequency when its support location is excited by the specified signal Clearly the damping of the simple

oscillator is an added parameter in a response spectrum specification Typical damping ratios ethzrTHORN used inresponse spectra specifications are less than 01 (or 10) It follows that an approximate relationship

between the Fourier spectrum of the support acceleration and its response spectrum is

as frac14 2jzrarethvTHORN eth18THORNThe magnitude larethvTHORNl is the response spectrumEquation 18 substituted into Equation 16 gives

F frac14 mHethvTHORN2jzrarethvTHORN eth19THORNIn view of Equation 17 for test packages having low damping the peak value of H(v) is

approximately 1=eth2jztTHORN this should be used in computing the force rating if the test package has a

resonance within the frequency range of testing On the other hand if the test package is assumed to be

rigid then HethvTHORN oslash 1 A conservative estimate for the force rating is

Fmax frac14 methzr=ztTHORNlarethvTHORNlmax eth110THORNIt should be noted that larethvTHORNlmax is the peak value of the specified (required) response spectrum (RRS)

for acceleration

1212 Power Rating

The exciter head does not develop its maximum force when driven at maximum velocity Output power

is determined by using

p frac14 Refrac12FvsethvTHORN eth111THORNin which vsethvTHORN is the Fourier spectrum of the exciter velocity and Re [ ] denotes the real part of a complex

function Note that as frac14 jvvs Substituting Equation 16 and Equation 18 into Equation 111 gives

p frac14 eth4mz2r =vTHORNRefrac12jHethvTHORNa2r ethvTHORN eth112THORNIt follows that a conservative estimate for the power rating is

pmax frac14 2methz2r =ztTHORNfrac12larethvTHORNl2=v max eth113THORN

Vibration Instrumentation 1-7

53191mdash522007mdash1201mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

Representative segments of typical acceleration RRS curves have slope n as given by

a frac14 k1vn eth114THORN

It should be clear from Equation 113 that the maximum output power is given by

pmax frac14 k2v2n21 eth115THORN

This is an increasing function for n 1=2 and a decreasing function for n 1=2 It follows that the power

rating corresponds to the highest point of contact between the acceleration RRS curve and a line of slope

equal to 12 A similar relationship may be derived if velocity RRS curves (having slopes n2 1) are used

1213 Stroke Rating

From Equation 18 it should be clear that the Fourier spectrum xs of the exciter displacement time

history can be expressed as

xs frac14 2zrarethvTHORN=jv2 eth116THORNAn estimate for stroke rating is

xmax frac14 2zrfrac12larethvTHORNl=v2 max eth117THORNThis is of the form

xmax frac14 kvn22 eth118THORNIt follows that the stroke rating corresponds to the highest point of contact between the acceleration

RRS curve and a line of slope equal to two

Example 11

A test package of overall mass 100 kg is to be

subjected to dynamic excitation represented by the

acceleration RRS (at 5 damping) as shown in

Figure 14 The estimated damping of the test

package is 7 The test package is known to have a

resonance within the frequency range of the

specified test Determine the exciter specifications

for the test

Solution

From the development presented in the previous

section it is clear that the point F (or P) in

Figure 14 corresponds to the force and output

power ratings and the point S corresponds to

the stroke rating The co-ordinates of these

critical points are F P frac14 eth42 Hz 40 gTHORN and S frac14 eth08 Hz 075 gTHORN Equation 110 gives the force

rating as

Fmax frac14 100 pound eth005=007THORN pound 40 pound 981 N frac14 2803 N

Equation 113 gives the power rating as

pmax frac14 2 pound 100 pound eth0052=007THORN pound frac12eth40 pound 981THORN2=42 pound 2p watts frac14 417 W

Equation 117 gives the stroke rating as

xmax frac14 2 pound 005 pound frac12eth075 pound 98THORN=eth08 pound 2pTHORN2 m frac14 3 cm

Acc

eler

atio

n(g

)

Con

stan

t Dis

plac

emen

t

Constant Velo

city

Frequency (Hz)

S

FP

0101

10 10 100

10

10

FIGURE 14 Test excitation specified by an accelera-

tion RRS (5 damping)

Vibration Monitoring Testing and Instrumentation1-8

53191mdash522007mdash1201mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

1214 Hydraulic Shakers

A typical hydraulic shaker consists of a piston-cylinder arrangement (also called a ram) a servo-valve a

fluid pump and a driving electric motor Hydraulic fluid (oil) is pressurized (typical operating pressure

4000 psi) and pumped into the cylinder through a servo-valve by means of a pump that is driven by an

electric motor (typical power 150 hp) The flow (typical rate 100 galmin) that enters the cylinder is

controlled (modulated) by the servo-valve which in effect controls the resulting piston (ram) motion

A typical servo-valve consists of a two-stage spool valve which provides a pressure difference and a

controlled (modulated) flow to the piston which sets it in motion

The servo-valve itself is moved by means of a linear torque motor which is driven by the excitation-

input signal (electrical) A primary function of the servo-valve is to provide a stabilizing feedback to the

ram In this respect the servo-valve complements the main control system of the test setup The ram is

coupled to the shaker table by means of a link with some flexibility The cylinder frame is mounted on the

support foundation with swivel joints This allows for some angular and lateral misalignment which

might be caused primarily by test-object dynamics as the table moves

Two-degree-of-freedom (Two-DoF) testing requires two independent sets of actuators and three-DoF

testing requires three independent actuator sets Each independent actuator set can consist of several

actuators operated in parallel using the same pump and the same excitation-input signal to the torque

motors

If the test table is directly supported on the vertical actuators they must withstand the total dead

weight (ie the weight of the test table the test object the mounting fixtures and the instrumentation)

This is requirement is usually prevented by providing a pressurized air cushion in the gap between the

test table and the foundation walls Air should be pressurized so as to balance the total dead weight

exactly (typical required gage pressure 3 psi)

Figure 15(a) shows the basic components of a typical hydraulic shaker The corresponding

operational block diagram is shown in Figure 15(b) It is desirable to locate the actuators in a pit in the

test laboratory so that the test tabletop is flushed with the test laboratory floor under no-load conditions

This minimizes the effort required to place the test object on the test table Otherwise the test object has

to be lifted onto the test table with a forklift Also installation of an aircushion to support the system

dead weight is difficult under these circumstances of elevated mounting

Hydraulic actuators are most suitable for heavy load testing and are widely used in industrial and civil

engineering applications They canbeoperated at very low frequencies (almost direct current [DC]) aswell

as at intermediate frequencies (see Table 11) Large displacements (stroke) are possible at low frequencies

Hydraulic shakers have the advantage of providing high flexibility of operation during the test their

capabilities include variable-force and constant-force testing and wide-band random-input testing The

velocity and acceleration capabilities of hydraulic shakers are moderate Although any general excitation-

input motion (for example sine wave sine beat wide-band random) can be used in hydraulic shakers

faithful reproduction of these signals is virtually impossible at high frequencies because of distortion and

higher-order harmonics introduced by the high noise levels that are common in hydraulic systems This

is only a minor drawback in heavy-duty intermediate-frequency applications Dynamic interactions are

reduced through feedback control

1215 Inertial Shakers

In inertial shakers or ldquomechanical excitersrdquo the force that causes the shaker-table motion is generated by

inertia forces (accelerating masses) Counter-rotating-mass inertial shakers are typical in this category

To understand their principle of operation consider two equal masses rotating in opposite directions at

the same angular speed v and in the same circle of radius r (see Figure 16) This produces a resultant

force equal to 2mv2r cos vt in a fixed direction (the direction of symmetry of the two rotating arms)

Consequently a sinusoidal force with a frequency of v and an amplitude proportional to v2 is generated

This reaction force is applied to the shaker table

Figure 17 shows a sketch of a typical counter-rotating-mass inertial shaker It consists of two identical

rods rotating at the same speed in opposite directions Each rod has a series of slots in which to

Vibration Instrumentation 1-9

53191mdash522007mdash1201mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

place weights In this manner the magnitude of

the eccentric mass can be varied to achieve various

force capabilities The rods are driven by a

variable-speed electric motor through a gear

mechanism that usually provides several speed

ratios A speed ratio is selected depending on the

required test-frequency range The whole system is

symmetrically supported on a carriage that is

directly connected to the test table The test object

is mounted on the test table The preferred

mounting configuration is horizontal so that the

excitation force is applied to the test object in a

horizontal direction In this configuration there

are no variable gravity moments (weight pounddistance to center of gravity) acting on the drive

mechanism Figure 17 shows the vertical con-

figuration In dynamic testing of large structures

the carriage can be mounted directly on the

structure at a location where the excitation force

should be applied By incorporating two pairs of

counter-rotating masses it is possible to generate

test moments as well as test forces

FIGURE 15 A typical hydraulic shaker arrangement (a) schematic diagram (b) operational block diagram

m m

2mw2r cos wt

wtw w

wt

FIGURE 16 Principle of operation of a counter-

rotating-mass inertial shaker

Vibration Monitoring Testing and Instrumentation1-10

53191mdash522007mdash1201mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

Reaction-type shakers driven by inertia are widely used for the prototype testing of civil engineering

structures Their first application dates back to 1935 Inertial shakers are capable of producing

intermediate excitation forces The force generated is limited by the strength of the carriage frame The

frequency range of operation and the maximum velocity and acceleration capabilities are also

intermediate for inertial shakers whereas the maximum displacement capability is typically low A major

limitation of inertial shakers is that their excitation force is exclusively sinusoidal and that the force

amplitude is directly proportional to the square of the excitation frequency As a result complex and

random excitation testing constant-force testing (for example transmissibility tests and constant-force

sine-sweep tests) and flexibility to vary the force amplitude or the displacement amplitude during a test

are not generally feasible with this type of shakers Excitation frequency and amplitude can be varied

during testing however by incorporating a variable-speed drive for the motor The sinusoidal excitation

generated by inertial shakers is virtually undistorted which gives them an advantage over the other types

of shakers when used in sine-dwell and sine-sweep tests Small portable shakers with low-force capability

are available for use in on-site testing

1216 Electromagnetic Shakers

In electromagnetic shakers or ldquoelectrodynamic excitersrdquo the motion is generated using the principle of

operation of an electric motor Specifically the excitation force is produced when a variable excitation

signal (electrical) is passed through a moving coil placed in a magnetic field

The components of a commercial electromagnetic shaker are shown in Figure 18 A steady magnetic

field is generated by a stationary electromagnet that consists of field coils wound on a ferromagnetic base

that is rigidly attached to a protective shell structure The shaker head has a coil wound around it When

the excitation electrical signal is passed through this drive coil the shaker head which is supported on

flexure mounts will be set in motion The shaker head consists of the test table on which the test object

is mounted Shakers with interchangeable heads are available The choice of appropriate shaker head is

based on the geometry and mounting features of the test object The shaker head can be turned to

different angles by means of a swivel joint In this manner different directions of excitation (in biaxial

and triaxial testing) can be obtained

FIGURE 17 Sketch of a counter-rotating-mass inertial shaker

Vibration Instrumentation 1-11

53191mdash522007mdash1202mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

122 Dynamics of Electromagnetic Shakers

Consider a single axis electromagnetic shaker (Figure 18) with a test object having a single natural

frequency of importance within the test frequency range The dynamic interactions between the shaker

and the test object give rise to two significant natural frequencies (and correspondingly two significant

resonances) These appear as peaks in the frequency response curve of the test setup Furthermore the

natural frequency (resonance) of the test package alone causes a ldquotroughrdquo or depression (antiresonance)

in the frequency response curve of the overall test setup To explain this characteristic consider the

dynamic model shown in Figure 19 The following mechanical parameters are defined for

Figure 19(a) m k and b are the mass stiffness and equivalent viscous damping constant respectively

of the test package and me ke and be are the corresponding parameters of the exciter (shaker) Also in

the equivalent electrical circuit of the shaker head as shown in Figure 19(b) the following electrical

parameters are defined Re and Le are the resistance and (leakage) inductance and kb is the back

electromotive force (back emf) of the linear motor Assuming that the gravitational forces are supported

FIGURE 18 Schematic sectional view of a typical electromagnetic shaker manufactured by Bruel and Kjaer

Denmark

Vibration Monitoring Testing and Instrumentation1-12

53191mdash522007mdash1202mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

by the static deflections of the flexible elements and that the displacements are measured from the static

equilibrium position we have the following system equations

Test object meuroy frac14 2kethy2 yeTHORN2 beth_y2 _yeTHORN eth119THORNShaker head me euroye frac14 fe thorn kethy2 yeTHORN thorn beth_y2 _yeTHORN2 key 2 be _ye eth120THORN

Electrical Lediedt

thorn Reie thorn kb _ye frac14 vethtTHORN eth121THORN

The electromagnetic force fe generated in the shaker head is a result of the interaction of the magnetic

field generated by the current ie with coil of the moving shaker head and the constant magnetic field

(stator) in which the head coil is located Here we have

fe frac14 kbie eth122THORNNote that v(t) is the voltage signal that is applied by the amplifier to the shaker coil ye is the displacement

of the shaker head and y is the displacement response of the test package

It is assumed that kb has consistent electrical and mechanical units (Vmsec and NA) Usually

the electrical time constant of the shaker is quite small compared with the primarily mechanical

time constants of the shaker and the test package In such cases the Ledie=dt term in Equation 121 may

be neglected Consequently the equations from Equation 119 through Equation 122 may be

expressed in the Laplace (frequency) domain with the Laplace variable s taking the place of the derivative

d=dt as

ethms2 thorn bsthorn kTHORNy frac14 ethbsthorn kTHORNye eth123THORN

FIGURE 19 Dynamic models of an electromagnetic shaker and a flexible test package (a) mechanical model

(b) electrical model

Vibration Instrumentation 1-13

53191mdash522007mdash1202mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

frac12mes2 thorn ethbthorn beTHORNsthorn ethkthorn keTHORN ye frac14 ethbsthorn kTHORNy thorn kb

Rev2

k2bs

Reye eth124THORN

It follows that the transfer function of the shaker head motion with respect to the excitation voltage is

given by

yevfrac14 kb

Re

DethsTHORNDdethsTHORN eth125THORN

where DethsTHORN is the characteristic function of the primary dynamics of the test object

DethsTHORN frac14 ms2 thorn bsthorn k eth126THORN

and DdethsTHORN is the characteristic function of the primary dynamic interactions between the shaker and thetest object

DcethsTHORN frac14 mmes4 thorn frac12methbe thorn bthorn boTHORN thornmeb s

3 thorn frac12methke thorn kTHORN thornmekthorn bethbe thorn boTHORN s2thorn frac12bke thorn ethbe thorn boTHORNk sthorn kke

eth127THORN

where

bo frac14 k2bRe

eth128THORN

It is clear that under low damping conditions DdethsTHORN will produce two resonances as it is fourth order in sand similarly DethsTHORN will produce one antiresonance (trough) corresponding to the resonance of the testobject Note that in the frequency domain s frac14 jv and hence the frequency response function given by

Equation 125 is in fact

yevfrac14 kb

Rb

DethjvTHORNDdethjvTHORN eth129THORN

The magnitude of this frequency response function for a typical test system is sketched in Figure 110

Note that this curve is for the ldquoopen-looprdquo case where there is no feedback from the shaker controller

In practice the shaker controller will be able

to compensate for the resonances and anti-

resonances to some degree depending on its

effectiveness

The main advantages of electromagnetic

shakers are their high frequency range of

operation their high degree of operating flexi-

bility and the high level of accuracy of the

generated shaker motion Faithful reproduction

of complex excitations is possible because of the

advanced electronics and control systems used in

this type of shakers Electromagnetic shakers are

not suitable for heavy-duty applications (large test

objects) however High test-input accelerations

are possible at high frequencies when electromag-

netic shakers are used but their displacement and

velocity capabilities are limited to low or

intermediate values (see Table 11)

100

10

1 10 100Excitation Frequency (Hz)

Antiresonance

Resonance

Shak

erD

ispl

acem

entM

agni

tude

Resonance

1000

FIGURE 110 Frequency response curve of a typical

electromagnetic shaker with a test object

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1221 Transient Exciters

Other varieties of exciters are commonly used in

transient-type vibration testing In these tests

either an impulsive force or an initial excitation is

applied to the test object and the resulting

response is monitored The excitations and the

responses are ldquotransientrdquo in this case Hammer

test drop tests and pluck tests fall into this

category For example a hammer test may be

conducted by hitting the object with an instru-

mented hammer and then measuring the response

of the object The hammer has a force sensor at its

tip as sketched in Figure 111 A piezoelectric or

strain-gage type force sensor may be used More

sophisticated hammers have impedance heads in

place of force sensors An impedance head

measures force and acceleration simultaneously

The results of a hammer test will depend on many

factors for example the dynamics of the hammer

body how firmly the hammer is held during the

impact how quickly the impact is applied and

whether there are multiple impacts

13 Control System

The two primary functions of the shaker control system in vibration testing are (1) to guarantee that the

specified excitation is applied to the test object and (2) to ensure that the dynamic stability (motion

constraints) of the test setup is preserved An operational block diagram illustrating these control

functions is given in Figure 112 The reference input to the control system represents the desired

excitation force that should be applied to the test object In the absence of any control however the force

reaching the test object will be distorted primarily because of (1) dynamic interactions and

nonlinearities of the shaker the test table the mounting fixtures the auxiliary instruments and the test

object itself (2) noise and errors in the signal generator amplifiers filters and other equipment and (3)

external loads and disturbances acting on the test object and other components (for example external

restraints aerodynamic forces friction) To compensate for these distorting factors response

measurements (displacements velocities acceleration and so on) are made at various locations in the

test setup and are used to control the system dynamics In particular the responses of the shaker the test

table and the test object are measured These responses are used to compare the actual excitation felt by

FIGURE 111 An instrumented hammer used in bump

tests or hammer tests

ExcitationInput

(Reference)

Feedback Paths

DriveSignal

ShakerResponse

TestTable

TestObject

Test ObjectResponse

Test TableResponseExciter

(Shaker)(Ram)

Controllerand

Amplifier

FIGURE 112 Operational block diagram illustrating a general shaker control system

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copy 2007 by Taylor amp Francis Group LLC

the test object at the shaker interface with the desired (specified) input The drive signal to the shaker is

modified depending on the error that is present

Two types of control are commonly employed in shaker apparatus simple manual control and

complex automatic control Manual control normally consists of simple open-loop trial-and-error

methods of manual adjustments (or calibration) of the control equipment to obtain a desired dynamic

response The actual response is usually monitored (on an oscilloscope or frequency analyzer screen for

example) during manual-control operations The pretest adjustments in manual control can be very

time-consuming as a result the test object might be subjected to overtesting which could produce

cumulative damage is undesirable and could defeat the test purpose Furthermore the calibration

procedure for the experimental setup must be repeated for each new test object

The disadvantages ofmanual control suggest that automatic control is desirable in complex test schemes

in which high accuracy of testing is desired The first step of automatic control involves automatic

measurement of the system response using control sensors and transducers The measurement is then fed

back into the control system which instantaneously determines the best drive signal to actuate the shaker

in order to get the desired excitation This may be done by either analog or digital methods

Primitive control systems require an accurate mathematical description of the test object This

dependency of the control system on the knowledge of test-object dynamics is clearly undesirable

Performance of a good control system should not be considerably affected by the dynamic interactions

and nonlinearities of the test object or by the nature of the excitation Proper selection of feedback signals

and control-system components can reduce such effects and will make the system robust

In the response-spectrum method of vibration testing it is customary to use displacement control at

low frequencies velocity control at intermediate frequency and acceleration control at high frequencies

This necessitates feedback of displacement velocity and acceleration responses Generally however the

most important feedback is the velocity feedback In sine-sweep tests the shaker velocity must change

steadily over the frequency band of interest In particular the velocity control must be precise near the

resonances of the test object Velocity (speed) feedback has a stabilizing effect on the dynamics which is

desirable This effect is particularly useful in ensuring stability in motion when testing is done near

resonances of lightly damped test objects On the contrary displacement (position) feedback can have a

destabilizing effect on some systems particularly when high feedback gains are used

The controller usually consists of various instruments equipment and computation hardware and

software Often the functions of the data-acquisition and processing system overlap with those of the

controller to some extent As an example consider the digital-controller of vibration testing apparatus

First the responses are measured through sensors (and transducers) filtered and amplified

(conditioned) These data channels may be passed through a multiplexer whose purpose is to select

one data channel at a time for processing Most modern data acquisition hardware does not need a

separate multiplexer to handle multiple signals The analog data are converted into digital data using

analog-to-digital converters (ADCs) The resulting sampled data are stored on a disk or as a block data in

the computer memory The reference input signal (typically a signal recorded on an FM tape) is also

sampled (if it is not already in the digital form) using an ADC and fed into the computer Digital

processing is done on the reference signal and the response data with the objective of computing the

command signal to drive the shaker The digital command signal is converted into an analog signal using

a digital-to-analog converter (DAC) and amplified (conditioned) before it is used to drive the exciter

The nature of the control components depends to a large extent on the nature and objectives of the

particular test to be conducted Some of the basic components in a shaker controller are described in

the following subsections

131 Components of a Shaker Controller

1311 Compressor

A compressor circuit is incorporated in automatic excitation control devices to control the excitation-

input level automatically The level of control depends on the feedback signal from a control sensor and

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copy 2007 by Taylor amp Francis Group LLC

the specified (reference) excitation signal Usually the compressor circuit is included in the excitation-

signal generator (for example in a sine generator) The control by this means may be done on the basis of

a single-frequency component (eg the fundamental frequency)

1312 Equalizer (Spectrum Shaper)

Random-signal equalizers are used to shape the spectrum of a random signal in a desired manner In

essence and equalizer consists of a bank of narrow-band filters (for example 80 filters) in parallel over

the operating frequency range By passing the signal through each filter the spectral density (or the mean

square value) of the signal in that narrow frequency band (for example each one-third-octave band) is

determined This is compared with the desired spectral level and automatic adjustment is made in that

filter in case there is an error In some systems response-spectrum analysis is made in place of power

spectral density analysis In that case the equalizer consists of a bank of simple oscillators whose

resonant frequencies are distributed over the operating frequency range of the equalizer The feedback

signal is passed through each oscillator and the peak value of its output is determined This value is

compared with the desired response spectrum value at that frequency If there is an error automatic gain

adjustment is made in the appropriate excitation signal components

Random-noise equalizers are used in conjunction with random signal generators They receive

feedback signals from the control sensors In some digital control systems there are algorithms (software)

that are used to iteratively converge the spectrum of the excitation signal felt by the test object into the

desired spectrum

1313 Tracking Filter

Many vibration tests are based on single-frequency excitations In such cases the control functions

should be performed on the basis of the amplitudes of the fundamental-frequency component of the

signal A tracking filter is simply a frequency-tuned band-pass filter It automatically tunes the center

frequency of its very narrow-band-pass filter to the frequency of a carrier signal Then when a noisy

signal is passed through the tuned filter the output of the filter will be the required fundamental

frequency component in the signal Tracking filters also are useful in obtaining amplitudendashfrequency

plots using an XndashY plotter In such cases the frequency value comes from the signal generator (sweep

oscillator) which produces the carrier signal to the tracking filter The tracking filter then determines the

corresponding amplitude of a signal that is fed into it Most tracking filters have dual channels so that two

signals can be handled (tracked) simultaneously

1314 Excitation Controller (Amplitude Servo-Monitor)

An excitation controller is typically an integral part of the signal generator It can be set so that automatic

sweep between two frequency limits can be performed at a selected sweep rate (linear or logarithmic)

More advanced excitation controllers have the capability of an automatic switch-over between constant-

displacement constant-velocity and constant-acceleration excitation-input control at specified

frequencies over the sweep frequency interval Consequently integrator circuits should be present

within the excitation controller unit to determine velocities and displacements from acceleration signals

Sometimes integration is performed by a separate unit called a vibration meter This unit also offers

the operator the capability of selecting the desired level of each signal (acceleration velocity or

displacement) There is an automatic cut-off level for large displacement values that could result from

noise in acceleration signals A compressor is also a subcomponent of the excitation controller The

complete unit is sometimes known as an amplitude servo-monitor

132 Signal-Generating Equipment

Shakers are force-generating devices that are operated using drive (excitation) signals generated from a

source The excitation-signal source is known as the signal generator Three major types of signal

generators are used in vibration testing applications (1) oscillators (2) random-signal generators and

(3) storage devices In some units oscillators and random-signal generators are combined We shall

Vibration Instrumentation 1-17

53191mdash522007mdash1202mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

discuss these two generators separately however because of their difference in function It also should be

noted that almost any digital signal (deterministic or random) can be generated by a digital computer

using a suitable computer program the signal eventually can be passed through a DAC to obtain

the corresponding analog signal These lsquodigitalrsquo signal generators along with analog sources such as

magnetic tape players (FM) are classified into the category of storage devices

The dynamic range of equipment is the ratio of the maximum and minimum output levels (expressed

in decibels) at which it is capable of operating without significant error This is an important specification

for many types of equipment particularly for signal-generating devices The output level of the signal

generator should be set to a value within its dynamic range

1321 Oscillators

Oscillators are essentially single-frequency generators Typically sine signals are generated but other

waveforms (such as rectangular and triangular pulses) are also available in most oscillators Normally

an oscillator has two modes of operation (1) sweeping up and down between two frequency limits and

(2) dwelling at a specified frequency In the sweep operation the sweep rate should be specified This can

be done either on a linear scale (Hzmin) or on a logarithmic scale (octavesmin) In the dwell operation

the frequency points (or intervals) should be specified In either case a desired signal level can be chosen

using the gain-control knob An oscillator that is operated exclusively in the sweep mode is called a sweep

oscillator

The early generation of oscillators employed variable inductor-capacitor types of electronic circuits to

generate signals oscillating at a desired frequency The oscillator is tuned to the required frequency by

varying the capacitance or inductance parameters A DC voltage is applied to energize the capacitor

and to obtain the desired oscillating voltage signal which subsequently is amplified and conditioned

Modern oscillators use operational amplifier circuits along with resistor capacitor and semiconductor

(SC) elements Also common are crystal (quartz) parallel-resonance oscillators used to generate voltage

signals accurately at a fixed frequency The circuit is activated using a DC-voltage source Other

frequencies of interest are obtained by passing this high-frequency signal through a frequency converter

The signal is then conditioned (amplified and filtered) Required shaping (for example rectangular

pulse) is obtained using a shape circuit Finally the required signal level is obtained by passing the

resulting signal through a variable-gain amplifier A block diagram of an oscillator illustrating various

stages in the generation of a periodic signal is given in Figure 113

A typical oscillator offers a choice of several (typically six) linear and logarithmic frequency ranges and

a sizable level of control capability (for example 80 dB) Upper and lower frequency limits in a sweep can

be preset on the front panel to any of the available frequency ranges Sweep-rate settings are continuously

DC Voltage

Oscillator

FrequencySpecification

FrequencyConverter

FilterAmplifier

ShaperPeriodicSignal

FrequencyCounter

Fixed-FrequencySignal

Variable-GainOutput

Amplifier

SignalSpecification

LevelSpecification

FIGURE 113 Block diagram of an oscillator-type signal generator

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copy 2007 by Taylor amp Francis Group LLC

  • 53191fm
    • Vibration Monitoring Testing and Instrumentation
      • Preface
      • Acknowledgments
      • Editor-in-Chief
      • Contributors
      • Contents
      • Related Titles
          • 53191ch1
            • Table of Contents
            • Chapter 1 Vibration Instrumentation
              • Summary
              • 11 Introduction
              • 12 Vibration Exciters
                • 121 Shaker Selection
                  • 1211 Force Rating
                  • 1212 Power Rating
                  • 1213 Stroke Rating
                  • 1214 Hydraulic Shakers
                  • 1215 Inertial Shakers
                  • 1216 Electromagnetic Shakers
                    • 122 Dynamics of Electromagnetic Shakers
                      • 1221 Transient Exciters
                          • 13 Control System
                            • 131 Components of a Shaker Controller
                              • 1311 Compressor
                              • 1312 Equalizer (Spectrum Shaper)
                              • 1313 Tracking Filter
                              • 1314 Excitation Controller (Amplitude Servo-Monitor)
                                • 132 Signal-Generating Equipment
                                  • 1321 Oscillators
                                  • 1322 Random Signal Generators
                                  • 1323 Tape Players
                                  • 1324 Data Processing
                                      • 14 Performance Specification
                                        • 141 Parameters for Performance Specification
                                          • 1411 Time-Domain Specifications
                                          • 1412 Frequency-Domain Specifications
                                            • 142 Linearity
                                            • 143 Instrument Ratings
                                              • 1431 Rating Parameters
                                                • 144 Accuracy and Precision
                                                  • 15 Motion Sensors and Transducers
                                                    • 151 Potentiometer
                                                      • 1511 Potentiometer Resolution
                                                      • 1512 Optical Potentiometer
                                                        • 152 Variable-Inductance Transducers
                                                          • 1521 Mutual-Induction Transducers
                                                          • 1522 Linear-Variable Differential Transformer
                                                          • 1523 Signal Conditioning
                                                            • 153 Mutual-Induction Proximity Sensor
                                                            • 154 Selfinduction Transducers
                                                            • 155 Permanent-Magnet Transducers
                                                            • 156 Alternating Current Permanent-Magnet Tachometer
                                                            • 157 Alternating Current Induction Tachometer
                                                            • 158 Eddy Current Transducers
                                                            • 159 Variable-Capacitance Transducers
                                                              • 1591 Capacitive Displacement Sensors
                                                              • 1592 Capacitive Angular Velocity Sensor
                                                              • 1593 Capacitance Bridge Circuit
                                                                • 1510 Piezoelectric Transducers
                                                                  • 15101 Sensitivity
                                                                  • 15102 Piezoelectric Accelerometer
                                                                  • 15103 Charge Amplifier
                                                                      • 16 Torque Force and Other Sensors
                                                                        • 161 Strain Gage Sensors
                                                                          • 1611 Equations for Strain Gage Measurements
                                                                          • 1612 Bridge Sensitivity
                                                                          • 1613 The Bridge Constant
                                                                          • 1614 The Calibration Constant
                                                                          • 1615 Data Acquisition
                                                                          • 1616 Accuracy Considerations
                                                                          • 1617 Semiconductor Strain Gages
                                                                          • 1618 Force and Torque Sensors
                                                                          • 1619 Strain Gage Torque Sensors
                                                                          • 16110 Deflection Torque Sensors
                                                                          • 16111 Variable-Reluctance Torque Sensor
                                                                          • 16112 Reaction Torque Sensors
                                                                            • 162 Miscellaneous Sensors
                                                                              • 1621 Stroboscope
                                                                              • 1622 Fiber Optic Sensors and Lasers
                                                                              • 1623 Fiber-Optic Gyroscope
                                                                              • 1624 Laser Doppler Interferometer
                                                                              • 1625 Ultrasonic Sensors
                                                                              • 1626 Gyroscopic Sensors
                                                                                  • References
                                                                                  • Appendix 1A Virtual Instrumentation for Data Acquisition Analysis and Presentation
                                                                                    • Summary
                                                                                    • List of Abbreviations
                                                                                    • 1A1 Dynamic Signals
                                                                                      • 1A11 Acquiring and Simulating Dynamic Signals
                                                                                        • 1A111 Aliasing
                                                                                        • 1A112 Time Continuity
                                                                                            • 1A2 Measurement Configuration Considerations
                                                                                              • 1A21 Input Signal Considerations
                                                                                                • 1A211 Input Pseudodifferential and Differential Configuration
                                                                                                • 1A212 Gain
                                                                                                • 1A213 Input Coupling
                                                                                                • 1A214 Integrated Electronic Piezoelectric Excitation
                                                                                                • 1A215 Nyquist Frequency and Bandwidth
                                                                                                • 1A216 Analog-to-Digital Conversion
                                                                                                • 1A217 Antialias Filters
                                                                                                • 1A218 Input Filter Delay
                                                                                                • 1A219 Overload Detection
                                                                                                  • 1A22 Output Signal Considerations
                                                                                                    • 1A221 Output Pseudodifferential and Differential Configuration
                                                                                                    • 1A222 Attenuation
                                                                                                    • 1A223 Digital-to-Analog Conversion
                                                                                                    • 1A224 Anti-imaging and Interpolation Filters
                                                                                                    • 1A225 Output Filter Delay
                                                                                                        • 1A3 Scaling and Calibration
                                                                                                          • 1A31 Scaling to Engineering Units
                                                                                                          • 1A32 Performing System Calibration
                                                                                                            • 1A321 Propagation Delay Calibration
                                                                                                                • 1A4 Limit Testing Analysis
                                                                                                                  • 1A41 Limit Testing Overview
                                                                                                                  • 1A42 Using the SVT Limit Testing VI
                                                                                                                    • 1A5 Integration
                                                                                                                      • 1A51 Introduction to Integration
                                                                                                                      • 1A52 Implementing Integration
                                                                                                                        • 1A521 Challenges when Integrating Vibration Data
                                                                                                                          • 1A53 Time-Domain Integration
                                                                                                                            • 1A531 Single-Shot Acquisition and Integration
                                                                                                                            • 1A532 Continuous Acquisition and Integration
                                                                                                                              • 1A54 Frequency-Domain Integration
                                                                                                                                • 1A6 Vibration-Level Measurements
                                                                                                                                  • 1A61 Measuring the Root Mean Square Level
                                                                                                                                    • 1A611 Single-Shot Buffered Acquisition
                                                                                                                                    • 1A612 Continuous Signal Acquisition
                                                                                                                                      • 1A62 Performing a Running RMS Level Measurement
                                                                                                                                      • 1A63 Computing the Peak Level
                                                                                                                                      • 1A64 Computing the Crest Factor
                                                                                                                                        • 1A7 Frequency Analysis
                                                                                                                                          • 1A71 FFT Fundamentals
                                                                                                                                            • 1A711 Number of Samples
                                                                                                                                            • 1A712 Frequency Resolution
                                                                                                                                            • 1A713 Maximum Resolvable Frequency
                                                                                                                                            • 1A714 Minimum Resolvable Frequency
                                                                                                                                            • 1A715 Number of Spectral Lines
                                                                                                                                            • 1A716 Relationship between Time-Domain and Frequency-Domain Specifications and Parameters
                                                                                                                                              • 1A72 Increasing Frequency Resolution
                                                                                                                                                • 1A721 Zoom FFT Analysis
                                                                                                                                                • 1A722 Frequency Resolution of the Zoom FFT VIs
                                                                                                                                                • 1A723 Zoom Measurement
                                                                                                                                                • 1A724 Zoom Settings
                                                                                                                                                • 1A725 Subset Analysis
                                                                                                                                                    • 1A8 Transient Analysis
                                                                                                                                                      • 1A81 Transient Analysis with the Sound and Vibration Toolkit
                                                                                                                                                      • 1A82 Performing an STFT vs Time
                                                                                                                                                        • 1A821 Selecting the FFT Block Size
                                                                                                                                                        • 1A822 Overlapping
                                                                                                                                                        • 1A823 Using the SVT STFT vs Time VI
                                                                                                                                                          • 1A83 Performing an STFT vs Rotational Speed
                                                                                                                                                            • 1A831 Converting the Pulse Train to Rotational Speed
                                                                                                                                                            • 1A832 STFT vs RPM
                                                                                                                                                              • 1A84 Measuring a Shock Response Spectrum
                                                                                                                                                                • 1A9 Waterfall Display
                                                                                                                                                                  • 1A91 Using the Display VIs
                                                                                                                                                                    • 1A911 Initializing the Display
                                                                                                                                                                    • 1A912 Sending Data to the Display
                                                                                                                                                                    • 1A913 Waterfall Display for Frequency Analysis
                                                                                                                                                                    • 1A914 Waterfall Display for Transient Analysis
                                                                                                                                                                    • 1A915 Waterfall Display for Octave Spectra
                                                                                                                                                                        • 1A10 Swept-Sine Measurements
                                                                                                                                                                          • 1A101 Swept-Sine Overview
                                                                                                                                                                          • 1A102 Choosing Swept-Sine vs FFT Measurements
                                                                                                                                                                          • 1A103 Taking a Swept-Sine Measurement
                                                                                                                                                                          • 1A104 Swept-Sine Measurement Example
                                                                                                                                                                              • Bibliography
                                                                                                                                                                              • Related Titles
                                                                                                                                                                                  • 53191ch2
                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                    • Chapter 2 Signal Conditioning and Modification
                                                                                                                                                                                      • Summary
                                                                                                                                                                                      • 21 Introduction
                                                                                                                                                                                      • 22 Amplifiers
                                                                                                                                                                                        • 221 Operational Amplifier
                                                                                                                                                                                        • 222 Use of Feedback in Opamp
                                                                                                                                                                                        • 223 Voltage Current and Power Amplifiers
                                                                                                                                                                                          • 2231 Charge Amplifiers
                                                                                                                                                                                            • 224 Instrumentation Amplifiers
                                                                                                                                                                                              • 2241 Differential Amplifier
                                                                                                                                                                                              • 2242 Common Mode
                                                                                                                                                                                                • 225 Amplifier Performance Ratings
                                                                                                                                                                                                  • 2251 Common-Mode Rejection Ratio
                                                                                                                                                                                                    • 226 Component Interconnection
                                                                                                                                                                                                      • 2261 Impedance Characteristics
                                                                                                                                                                                                      • 2262 Cascade Connection of Devices
                                                                                                                                                                                                      • 2263 AC-Coupled Ampliers
                                                                                                                                                                                                          • 23 Analog Filters
                                                                                                                                                                                                            • 231 Passive Filters and Active Filters
                                                                                                                                                                                                              • 2311 Number of Poles
                                                                                                                                                                                                                • 232 Low-Pass Filters
                                                                                                                                                                                                                  • 2321 Low-Pass Butterworth Filter
                                                                                                                                                                                                                    • 233 High-Pass Filters
                                                                                                                                                                                                                    • 234 Band-Pass Filters
                                                                                                                                                                                                                      • 2341 Resonance-Type Band-Pass Filters
                                                                                                                                                                                                                        • 235 Band-Reject Filters
                                                                                                                                                                                                                          • 24 Modulators and Demodulators
                                                                                                                                                                                                                            • 241 Amplitude Modulation
                                                                                                                                                                                                                              • 2411 Modulation Theorem
                                                                                                                                                                                                                              • 2412 Side Frequencies and Side Bands
                                                                                                                                                                                                                                • 242 Application of Amplitude Modulation
                                                                                                                                                                                                                                  • 2421 Fault Detection and Diagnosis
                                                                                                                                                                                                                                    • 243 Demodulation
                                                                                                                                                                                                                                      • 25 Analog ndashDigital Conversion
                                                                                                                                                                                                                                        • 251 Digital-to-Analog Conversion
                                                                                                                                                                                                                                          • 2511 DAC Error Sources
                                                                                                                                                                                                                                            • 252 Analog-to-Digital Conversion
                                                                                                                                                                                                                                            • 253 Analog-to-Digital Converter Performance Characteristics
                                                                                                                                                                                                                                              • 2531 Resolution and Quantization Error
                                                                                                                                                                                                                                              • 2532 Monotonicity Nonlinearity and Offset Error
                                                                                                                                                                                                                                              • 2533 Analog-to-Digital Converter Conversion Rate
                                                                                                                                                                                                                                                • 254 Sample-and-Hold Circuitry
                                                                                                                                                                                                                                                • 255 Digital Filters
                                                                                                                                                                                                                                                  • 2551 Software Implementation and Hardware Implementation
                                                                                                                                                                                                                                                      • 26 Bridge Circuits
                                                                                                                                                                                                                                                        • 261 Wheatstone Bridge
                                                                                                                                                                                                                                                        • 262 Constant-Current Bridge
                                                                                                                                                                                                                                                        • 263 Bridge Amplifiers
                                                                                                                                                                                                                                                          • 2631 Half-Bridge Circuits
                                                                                                                                                                                                                                                            • 264 Impedance Bridges
                                                                                                                                                                                                                                                              • 2641 Owen Bridge
                                                                                                                                                                                                                                                              • 2642 Wien-Bridge Oscillator
                                                                                                                                                                                                                                                                  • 27 Linearizing Devices
                                                                                                                                                                                                                                                                    • 271 Linearization by Software
                                                                                                                                                                                                                                                                    • 272 Linearization by Hardware Logic
                                                                                                                                                                                                                                                                    • 273 Analog Linearizing Circuitry
                                                                                                                                                                                                                                                                    • 274 Offsetting Circuitry
                                                                                                                                                                                                                                                                    • 275 Proportional-Output Circuitry
                                                                                                                                                                                                                                                                      • 2751 Curve-Shaping Circuitry
                                                                                                                                                                                                                                                                          • 28 Miscellaneous Signal Modification Circuitry
                                                                                                                                                                                                                                                                            • 281 Phase Shifters
                                                                                                                                                                                                                                                                            • 282 Voltage-to-Frequency Converter
                                                                                                                                                                                                                                                                            • 283 Frequency-to-Voltage Converter
                                                                                                                                                                                                                                                                            • 284 Voltage-to-Current Converters
                                                                                                                                                                                                                                                                            • 285 Peak-Hold Circuits
                                                                                                                                                                                                                                                                              • 29 Signal Analyzers and Display Devices
                                                                                                                                                                                                                                                                                • 291 Signal Analyzers
                                                                                                                                                                                                                                                                                • 292 Oscilloscopes
                                                                                                                                                                                                                                                                                  • 2921 Triggering
                                                                                                                                                                                                                                                                                  • 2922 Lissajous Patterns
                                                                                                                                                                                                                                                                                  • 2923 Digital Oscilloscopes
                                                                                                                                                                                                                                                                                      • Bibliography
                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                          • 53191ch3
                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                            • Chapter 3 Vibration Testing
                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                              • 31 Introduction
                                                                                                                                                                                                                                                                                              • 32 Representation of a Vibration Environment
                                                                                                                                                                                                                                                                                                • 321 Test Signals
                                                                                                                                                                                                                                                                                                  • 3211 Stochastic vs Deterministic Signals
                                                                                                                                                                                                                                                                                                    • 322 Deterministic Signal Representation
                                                                                                                                                                                                                                                                                                      • 3221 Single-Frequency Signals
                                                                                                                                                                                                                                                                                                      • 3222 Sine Sweep
                                                                                                                                                                                                                                                                                                      • 3223 Sine Dwell
                                                                                                                                                                                                                                                                                                      • 3224 Decaying Sine
                                                                                                                                                                                                                                                                                                      • 3225 Sine Beat
                                                                                                                                                                                                                                                                                                      • 3226 Sine Beat with Pauses
                                                                                                                                                                                                                                                                                                      • 3227 Multifrequency Signals
                                                                                                                                                                                                                                                                                                      • 3228 Actual Excitation Records
                                                                                                                                                                                                                                                                                                      • 3229 Simulated Excitation Signals
                                                                                                                                                                                                                                                                                                        • 323 Stochastic Signal Representation
                                                                                                                                                                                                                                                                                                          • 3231 Ergodic Random Signals
                                                                                                                                                                                                                                                                                                          • 3232 Stationary Random Signals
                                                                                                                                                                                                                                                                                                          • 3233 Independent and Uncorrelated Signals
                                                                                                                                                                                                                                                                                                          • 3234 Transmission of Random Excitations
                                                                                                                                                                                                                                                                                                            • 324 Frequency-Domain Representations
                                                                                                                                                                                                                                                                                                              • 3241 Fourier Spectrum Method
                                                                                                                                                                                                                                                                                                              • 3242 Power Spectral Density Method
                                                                                                                                                                                                                                                                                                                • 325 Response Spectrum
                                                                                                                                                                                                                                                                                                                  • 3251 Displacement Velocity and Acceleration Spectra
                                                                                                                                                                                                                                                                                                                  • 3252 Response-Spectra Plotting Paper
                                                                                                                                                                                                                                                                                                                  • 3253 Zero-Period Acceleration
                                                                                                                                                                                                                                                                                                                  • 3254 Uses of Response Spectra
                                                                                                                                                                                                                                                                                                                    • 326 Comparison of Various Representations
                                                                                                                                                                                                                                                                                                                      • 33 Pretest Procedures
                                                                                                                                                                                                                                                                                                                        • 331 Purpose of Testing
                                                                                                                                                                                                                                                                                                                        • 332 Service Functions
                                                                                                                                                                                                                                                                                                                          • 3321 Active Equipment
                                                                                                                                                                                                                                                                                                                          • 3322 Passive Equipment
                                                                                                                                                                                                                                                                                                                          • 3323 Functional Testing
                                                                                                                                                                                                                                                                                                                            • 333 Information Acquisition
                                                                                                                                                                                                                                                                                                                              • 3331 Interface Details
                                                                                                                                                                                                                                                                                                                              • 3332 Effect of Neglecting Interface Dynamics
                                                                                                                                                                                                                                                                                                                              • 3333 Effects of Damping
                                                                                                                                                                                                                                                                                                                              • 3334 Effects of Inertia
                                                                                                                                                                                                                                                                                                                              • 3335 Effect of Natural Frequency
                                                                                                                                                                                                                                                                                                                              • 3336 Effect of Excitation Frequency
                                                                                                                                                                                                                                                                                                                              • 3337 Other Effects of Interface
                                                                                                                                                                                                                                                                                                                                • 334 Test-Program Planning
                                                                                                                                                                                                                                                                                                                                  • 3341 Testing of Cabinet-Mounted Equipment
                                                                                                                                                                                                                                                                                                                                    • 335 Pretest Inspection
                                                                                                                                                                                                                                                                                                                                      • 34 Testing Procedures
                                                                                                                                                                                                                                                                                                                                        • 341 Resonance Search
                                                                                                                                                                                                                                                                                                                                        • 342 Methods of Determining Frequency-Response Functions
                                                                                                                                                                                                                                                                                                                                          • 3421 Fourier Transform Method
                                                                                                                                                                                                                                                                                                                                          • 3422 Spectral Density Method
                                                                                                                                                                                                                                                                                                                                          • 3423 Harmonic Excitation Method
                                                                                                                                                                                                                                                                                                                                            • 343 Resonance-Search Test Methods
                                                                                                                                                                                                                                                                                                                                              • 3431 Hammer (Bump) Test and Drop Test
                                                                                                                                                                                                                                                                                                                                              • 3432 Pluck Test
                                                                                                                                                                                                                                                                                                                                              • 3433 Shaker Tests
                                                                                                                                                                                                                                                                                                                                                • 344 Mechanical Aging
                                                                                                                                                                                                                                                                                                                                                  • 3441 Equivalence for Mechanical Aging
                                                                                                                                                                                                                                                                                                                                                  • 3442 Excitation-Intensity Equivalence
                                                                                                                                                                                                                                                                                                                                                  • 3443 Dynamic-Excitation Equivalence
                                                                                                                                                                                                                                                                                                                                                  • 3444 Cumulative Damage Theory
                                                                                                                                                                                                                                                                                                                                                    • 345 Test-Response Spectrum Generation
                                                                                                                                                                                                                                                                                                                                                    • 346 Instrument Calibration
                                                                                                                                                                                                                                                                                                                                                    • 347 Test-Object Mounting
                                                                                                                                                                                                                                                                                                                                                    • 348 Test-Input Considerations
                                                                                                                                                                                                                                                                                                                                                      • 3481 Test Nomenclature
                                                                                                                                                                                                                                                                                                                                                      • 3482 Testing with Uncorrelated Excitations
                                                                                                                                                                                                                                                                                                                                                      • 3483 Symmetrical Rectilinear Testing
                                                                                                                                                                                                                                                                                                                                                      • 3484 Geometry vs Dynamics
                                                                                                                                                                                                                                                                                                                                                      • 3485 Some Limitations
                                                                                                                                                                                                                                                                                                                                                      • 3486 Testing Black Boxes
                                                                                                                                                                                                                                                                                                                                                      • 3487 Phasing of Excitations
                                                                                                                                                                                                                                                                                                                                                      • 3488 Testing a Gray or White Box
                                                                                                                                                                                                                                                                                                                                                      • 3489 Overtesting in Multitest Sequences
                                                                                                                                                                                                                                                                                                                                                          • 35 Some Practical Information
                                                                                                                                                                                                                                                                                                                                                            • 351 Random Vibration Test Example
                                                                                                                                                                                                                                                                                                                                                            • 352 Vibration Shakers and Control Systems
                                                                                                                                                                                                                                                                                                                                                              • Bibliography
                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                  • 53191ch4
                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                    • Chapter 4 Experimental Modal Analysis
                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                      • 41 Introduction
                                                                                                                                                                                                                                                                                                                                                                      • 42 Frequency-Domain Formulation
                                                                                                                                                                                                                                                                                                                                                                        • 421 Transfer-Function Matrix
                                                                                                                                                                                                                                                                                                                                                                        • 422 Principle of Reciprocity
                                                                                                                                                                                                                                                                                                                                                                          • 43 Experimental Model Development
                                                                                                                                                                                                                                                                                                                                                                            • 431 Extraction of the Time-Domain Model
                                                                                                                                                                                                                                                                                                                                                                              • 44 Curve Fitting of Transfer Functions
                                                                                                                                                                                                                                                                                                                                                                                • 441 Problem Identification
                                                                                                                                                                                                                                                                                                                                                                                • 442 Single- and Multi-Degree-of-Freedom Techniques
                                                                                                                                                                                                                                                                                                                                                                                • 443 Single-Degree-of-Freedom Parameter Extraction in the Frequency Domain
                                                                                                                                                                                                                                                                                                                                                                                  • 4431 Circle-Fit Method
                                                                                                                                                                                                                                                                                                                                                                                    • Case of Viscous Damping
                                                                                                                                                                                                                                                                                                                                                                                    • Case of Hysteretic Damping
                                                                                                                                                                                                                                                                                                                                                                                      • 4432 Peak-Picking Method
                                                                                                                                                                                                                                                                                                                                                                                        • 444 Multi-Degree of Freedom Curve Fitting
                                                                                                                                                                                                                                                                                                                                                                                          • 4441 Formulation of the Method
                                                                                                                                                                                                                                                                                                                                                                                            • 445 A Comment on Static Modes and Rigid-Body Modes
                                                                                                                                                                                                                                                                                                                                                                                            • 446 Residue Extraction
                                                                                                                                                                                                                                                                                                                                                                                              • 45 Laboratory Experiments
                                                                                                                                                                                                                                                                                                                                                                                                • 451 Lumped-Parameter System
                                                                                                                                                                                                                                                                                                                                                                                                  • 4511 Frequency-Domain Test
                                                                                                                                                                                                                                                                                                                                                                                                  • 4512 Time-Domain Tests
                                                                                                                                                                                                                                                                                                                                                                                                    • 452 Distributed-Parameter System
                                                                                                                                                                                                                                                                                                                                                                                                      • 46 Commercial EMA Systems
                                                                                                                                                                                                                                                                                                                                                                                                        • 461 System Configuration
                                                                                                                                                                                                                                                                                                                                                                                                          • 4611 FFT Analysis Options
                                                                                                                                                                                                                                                                                                                                                                                                          • 4612 Modal Analysis Components
                                                                                                                                                                                                                                                                                                                                                                                                              • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                  • 53191ch5
                                                                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                    • Chapter 5 Mechanical Shock
                                                                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                      • 51 Definitions
                                                                                                                                                                                                                                                                                                                                                                                                                        • 511 Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 512 Simple (or Perfect) Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 513 Half-Sine Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 514 Versed-Sine (or Haversine) Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 515 Terminal Peak Sawtooth Shock or Final Peak Sawtooth Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 516 Rectangular Shock
                                                                                                                                                                                                                                                                                                                                                                                                                          • 5161 Trapezoidal Shock
                                                                                                                                                                                                                                                                                                                                                                                                                              • 52 Description in the Time Domain
                                                                                                                                                                                                                                                                                                                                                                                                                              • 53 Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                • 531 Need
                                                                                                                                                                                                                                                                                                                                                                                                                                • 532 Shock Response Spectrum Definition
                                                                                                                                                                                                                                                                                                                                                                                                                                • 533 Response of a Linear One-Degree-of-Freedom System
                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5331 Shock Defined by a Force
                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5332 Shock Defined by an Acceleration
                                                                                                                                                                                                                                                                                                                                                                                                                                    • 534 Definitions
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5341 Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5342 Absolute Acceleration Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5343 Relative Displacement Shock Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5344 Primary Positive Shock Response Spectrum or Initial Positive Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5345 Primary (or Initial) Negative Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5346 Secondary (or Residual) Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5347 Positive (or Maximum Positive) Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5348 Negative (or Maximum Negative) Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5349 Maximax Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53410 Choice of Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                        • 535 Standardized Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5351 Definition
                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5352 Standardized Shock Response Spectra of Simple Shocks
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53521 Half-Sine Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53522 Versed Sine Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53523 Terminal Peak Sawtooth Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53524 Rectangular Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53525 Trapezoidal Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 536 Choice of Damping
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 537 Shock Response Spectra Domains
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 538 Algorithms for Calculation of the Shock Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 539 Choice of the Digitization Frequency of the Signal
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5310 Use of Shock Response Spectra for the Study of Systems with Several Degrees of Freedom
                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 54 Pyroshocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 55 Use of Shock Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 551 Severity Comparison of Several Shocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 552 Test Specification Development from Real Environment Data
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5521 Synthesis of Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5522 Nature of the Specification
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5523 Choice of Shape
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5524 Amplitude
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5525 Duration
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5526 Difficulties
                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 56 Standards
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 561 Types of Standards
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 562 Installation Conditions of Test Item
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 563 Uncertainty Factor
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 564 Bump Test
                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 57 Damage Boundary Curve
                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 571 Definition
                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 572 Analysis of Test Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 58 Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 581 Main Types
                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 582 Impact Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5821 Universal Shock-Test Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 58211 Impact Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 58212 Impulse Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 583 Shock Simulators (Programmers)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5831 Half-Sine Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58311 Shock Duration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58312 Impact Velocity
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58313 Maximum Deformation of the Shock Simulator (Programmer)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58314 Shock Amplitude
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58315 Characteristics of the Target
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5832 Terminal Peak Sawtooth Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5833 Rectangular Pulse ndash Trapezoidal Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5834 Universal Shock Simulator (Programmer)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 58341 Generating a Half-Sine Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 58342 Generating a Terminal Peak Sawtooth Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 58343 Trapezoidal Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 584 Limitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5841 Limitations of the Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5842 Limitations of Shock Simulators
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 585 Pneumatic Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 586 High Impact Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5861 Lightweight High Impact Shock Machine
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5862 Medium Weight High Impact Shock Machine
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 587 Specific Test Facilities
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 59 Generation of Shock Using Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 591 Principle Behind the Generation of a Simple Shape Signal versus Time
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 592 Main Advantages
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 593 Pre- and Postshocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5931 Requirements
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5932 Solutions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 59321 Optimized Pre- and Postpulses
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5933 Incidence on the Shock Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 594 Limitations of Electrodynamic Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5941 Mechanical Limitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 59411 Abacuses
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5942 Electronic Limitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 595 The Use of Electrohydraulic Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 510 Control by a Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 5101 Principle
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 5102 Principal Shapes of Elementary Signals
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 51021 Decaying Sinusoid
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 51022 ZERD Function
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 51023 WAVSIN Waveform
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 5103 Comparison of WAVSIN SHOC Waveforms and Decaying Sinusoid
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 5104 Criticism of Control by a Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 511 Pyrotechnic Shock Simulation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5111 Simulation Using Pyrotechnic Facilities
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5112 Simulation Using Metal-to-Metal Impact
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5113 Simulation Using Electrodynamic Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5114 Simulation Using Conventional Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53191ch6
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Chapter 6 Machine Condition Monitoring and Fault Diagnostics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 61 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 62 Machinery Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 621 Causes of Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 622 Types of Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 623 Frequency of Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 63 Basic Maintenance Strategies
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 631 Run-to-Failure (Breakdown) Maintenance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 632 Scheduled (Preventative) Maintenance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 633 Condition-Based (Predictive Proactive Reliability Centered On-Condition) Maintenance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 64 Factors Which Influence Maintenance Strategy
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 65 Machine Condition Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 651 Periodic Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 652 Continuous Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 66 Transducer Selection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 661 Noncontact Displacement Transducers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 662 Velocity Transducers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 663 Acceleration Transducers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 67 Transducer Location
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 68 Recording and Analysis Instrumentation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 681 Vibration Meters
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 682 Data Collectors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 683 Frequency-Domain Analyzers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 684 Time-Domain Instruments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 685 Tracking Analyzers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 69 Display Formats and Analysis Tools
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 691 Time Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6911 Time-Waveform Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6912 Time-Waveform Indices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6913 Time-Synchronous Averaging
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6914 Negative Averaging
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6915 Orbits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6916 Probability Density Functions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6917 Probability Density Moments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 692 Frequency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6921 Band-Pass Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6922 Shock Pulse (Spike Energy)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6923 Enveloped Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6924 Signature Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6925 Cascades (Waterfall Plots)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6926 Masks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6927 Frequency-Domain Indices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 693 Modal Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 694 Quefrency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 610 Fault Detection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 6101 Standards
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61011 Standards Based on Machinery Type
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61012 Standards Based on Vibration Severity
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 6102 Acceptance Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 61021 Statistical Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 6103 Frequency-Domain Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61031 Limited Band Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61032 Constant Bandwidth Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61033 Constant Percentage Bandwidth Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 611 Fault Diagnostics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 6111 Forcing Functions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61111 Unbalance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61112 Misalignment
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61113 Mechanical Looseness
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61114 Soft Foot
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61115 Rubs
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61116 Resonances
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61117 Oil Whirl
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61118 Oil Whip
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61119 Structural Vibrations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 611110 Foundation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 6112 Specific Machine Components
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 61121 Damaged or Worn Rolling-Element Bearings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 61122 Damaged or Worn Gears
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 6113 Specific Machine Types
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61131 Pumps
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61132 Fans
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61133 Electric Motors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61134 Steam and Gas Turbines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61135 Compressors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61136 Reciprocating Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 6114 Advanced Fault Diagnostic Techniques
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 53191ch7
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • Chapter 7 Vibration-Based Tool Condition Monitoring Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 71 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 72 Mechanics of Turning
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 721 General Terms
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 722 Chatter Vibrations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 723 Tool Wear
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7231 Tool Failure Mechanisms
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7232 Tool Failure Modes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7233 Tool Wear Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7234 Tool Wear Stages
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 73 Vibration Signal Recording
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 731 Direct and Indirect Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 732 Sensor Requirements for Tool Wear Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 733 Force Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7331 Direct Measurement Dynamometers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7332 Indirect Force Sensors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7333 Piezoelectric Strain Sensors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7334 Resistance Strain Gauges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7335 Customized Force Sensors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 734 Acceleration Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 735 Acoustic Emission Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 736 Sensor Comparisons
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 74 Signal Processing for Sensor-Based Tool Condition Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 741 Feature Extraction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7411 Time Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7412 Frequency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7413 Statistical Processing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7414 TimendashFrequency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 742 Feature Selection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 75 Wear ModelDecision-Making for Sensor-Based Tool Condition Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 751 Trending Threshold
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 752 Neural Networks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7521 Unsupervised Networks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7522 Supervised Networks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 753 Fuzzy Logic
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 754 Other Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 76 Conclusion
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53191ch8
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Chapter 8 Fault Diagnosis of Helicopter Gearboxes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 81 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 82 Abnormality Scaling
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 83 The Structure-Based Connectionist Network
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 84 Sensor Location Selection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 841 Coverage Index
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 842 Overlap Index
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 843 Monitoring Effectiveness
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 85 A Case Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 851 Structural and Featural Influences
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 852 Evaluation of Influences
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 853 Fault Detection Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 854 Fault Diagnostic Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 8541 Faulty Subsystem Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 8542 Faulty Component Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 855 Sensor Location Evaluation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 856 Sensor Location Validation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 86 Conclusion
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 53191ch9
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Chapter 9 Vibration Suppression and Monitoring in Precision Motion Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 91 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 92 Mechanical Design to Minimize Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 921 Stability and Static Determinacy of Machine Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 922 Two-Dimensional Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 923 Three-Dimensional Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 93 Adaptive Notch Filter
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 931 Fast Fourier Transform
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 932 Simulation and Experiments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 94 Real-Time Vibration Analyzer
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 941 Learning Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 942 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 943 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 944 Experiments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 9441 Input Variables mdash the Evaluation Criteria
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 94411 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 94412 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 9442 Evaluation Rules
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 94421 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 94422 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 9443 Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 94431 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 94432 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 95 Practical Insights and Case Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 96 Conclusions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 53191ch10
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Chapter 10 Vibration and Shock Problems of Civil Engineering Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 101 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 102 Earthquake-Induced Vibration of Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1021 Seismicity and Ground Motions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1022 Influence of Local Site Conditions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1023 Response of Structures to Ground Motions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1024 Dynamic Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10241 Equations of Motion for Linear Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10242 Equations of Motion for Linear Multiple-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1025 Earthquake Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10251 Elastic Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10252 Smoothed Design Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10253 Ductility-Modified Response Spectrum Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1026 Design Philosophy and the Code Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10261 Performance-Based Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1027 Analysis Options for Earthquake Effects
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10271 Dynamic Time History Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10272 Response Spectrum Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 102721 Response Spectrum Analysis of Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 102722 Response Spectrum Analysis of Multi-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10273 Equivalent Static Analysis (Force-Based Approach)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10274 Displacement-Based Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1028 SoilndashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1029 Active and Passive Control Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 10210 Worked Examples
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 103 Dynamic Effects of Wind Loading on Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1031 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1032 Wind Speed
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1033 Design Structures for Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10331 Types of Wind Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10332 Design Criteria
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10333 Static Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1034 Along and Across-Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10341 Along-Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10342 Across-Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1035 Wind Tunnel Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1036 Comfort Criteria Human Response to Building Motion
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1037 Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1038 Comparison with Earthquake Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 104 Vibrations Due to Fluid ndashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1041 Added Mass and Inertial Coupling
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1042 Wave-Induced Vibration of Structure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 105 Blast Loading and Blast Effects on Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1051 Explosions and Blast Phenomenon
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1052 Explosive Air-Blast Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10521 Blast Wave Scaling Laws
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10522 Prediction of Blast Pressure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1053 Gas Explosion Loading and Effect of Internal Explosions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1054 Structural Response to Blast Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10541 Elastic Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10542 Elasto-Plastic Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1055 Material Behaviors at High Strain Rate
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10551 Dynamic Properties of Concrete under High Strain Rates
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10552 Dynamic Properties of Reinforcing Steel under High Strain Rates
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1056 Failure Modes of Blast-Loaded Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10561 Global Structural Behavior
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10562 Localized Structural Behavior
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10563 PressurendashImpulse ( PndashI ) Diagrams
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1057 Blast WavendashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1058 Effect of Ground Shocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10581 Loads from Air-Induced Ground Shock
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10582 Loads from Direct Ground Shock
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1059 Technical Design Manuals for Blast-Resistant Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 10510 Computer Programs for Blast and Shock Effects
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 106 Impact Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1061 Structural Impact between Two Bodies mdash Hard Impact and Soft Impact
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1062 Example mdash Aircraft Impact
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 107 Floor Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1071 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1072 Types of Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10721 Walking
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10722 Rhythmic Activities
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10723 Mechanical Equipment
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10724 Analysis Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1073 Natural Frequency of Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10731 Computing the Natural Frequency
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10732 Computing Deflection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10733 Damping
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10734 Resonance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1074 Vibration Caused by Walking
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10741 Minimum Natural Frequency
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1075 Design for Rhythmic Excitation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10751 Harmonics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10752 Minimum Natural Frequency
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1076 Example mdash Vibration Analysis of a Reinforced Concrete Floor
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 53191ch11
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Chapter 11 Seismic Base Isolation and Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 111 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1111 From Ductility Design to Base Isolation and Control Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1112 The Importance of Reducing Seismic Input and Response
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 112 Seismic Base Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1121 Historical Development of Base Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1122 Basic Principle
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1123 Issues in Seismic Base Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11231 Performance Criteria
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11232 Type of Structure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11233 Site Characteristics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11234 Retrofit Issues
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11235 Design of Building Services
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11236 Expected Life of Isolator
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1124 Seismic Isolation Devices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11241 Laminated Rubber Bearings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11242 Lead Rubber Bearing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11243 Friction-Based Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11244 Other Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1125 Design of Isolation Devices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11251 High-Damping Rubber Bearing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112511 Stability against Buckling
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112512 Stability against Roll Out
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11252 Lead Rubber Bearings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112521 Design of Lead Plug
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112522 Design of Laminated Rubber Bearing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11253 Design of Friction Pendulum System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1126 Verification of Properties of Isolation Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11261 Tests for Isolation Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 112611 System Characterization Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 112612 Prototype Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 112613 Quality Control Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11262 Uniform Building Code Recommendations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112621 Units Dependent on Loading Rates
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112622 Units Dependent on Bilateral Load
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112623 System Adequacy
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1127 Analysis of Base-Isolated Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11271 Modeling of a Superstructure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11272 Modeling of Isolation System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11273 Static Analysis Procedure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11274 Dynamic Analysis Procedure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 112741 Response Spectrum Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 112742 Time-History Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11275 Software for Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1128 Experimental Methods for Isolated Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1129 Implementation of Seismic Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11291 New Construction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112911 Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112912 Bridges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11292 Seismic Retrofit
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112921 Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112922 Bridges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11293 Other Implementations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 11210 Performance during Past Earthquakes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 112101 Performance of Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 112102 Performance of Bridges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 113 Seismic Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1131 Historical Development of Seismic Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1132 Basic Principles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11321 Passive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11322 Active Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11323 Semiactive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11324 Hybrid Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11325 Categorization of Basic Principles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1133 Important Issues in Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11331 SoilndashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11332 DevicendashStructure Interaction and Time Delay
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11333 Design Guidelines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1134 Vibration-Control Devices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11341 Passive Control Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113411 Metallic Yielding Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113412 Friction Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113413 Viscoelastic Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113414 Viscous Fluid Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113415 Tuned Mass Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11342 Active Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113421 Electromagnetic Actuator
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113422 Hydraulic Actuators
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11343 Semiactive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113431 Variable-Orifice Hydraulic Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113432 Controllable Fluid Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113433 Controllable Friction Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11344 Hybrid Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1135 Control Algorithm
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11351 Active Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11352 Semiactive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113521 Common Control Schemes for Controllable Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113522 Special Control Schemes for Controllable Damper
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1136 Experimental Performance Verification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11361 Shaking Table Tests of a Flexible Structural Model with TMD AMD and ATMD
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11362 Substructure Hybrid Test
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113621 Hybrid Tests Using Hydraulic Actuator
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113622 Hybrid Tests Using Shaking Table
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113623 Hybrid Tests Using Inertia-Force-Driven Loading System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1137 Implementations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11371 Semiactive Control of Full-Scale Structures Using Variable Joint Damper System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113711 Background of Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113712 Test System Set Up
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113713 Control Algorithm
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113714 Test Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11372 Application of Structural Control Technologies to Seismic Retrofit of a Cable-Stayed Bridge
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113721 Background of Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113722 Basic Concept of Seismic Retrofit
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113723 Modal Shape Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113724 Time-History Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113725 Soil ndash Structure Interaction Effect
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113726 Semiactive Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53191ch12
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Chapter 12 Seismic Random Vibration of Long-Span Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 121 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1211 Basic Concepts of Random Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12111 Stationary Random Process
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12112 Nonstationary Random Process
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1212 Three Methods for Structural Seismic Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12121 Response Spectrum Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12122 Time-History Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12123 Random Vibration Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 121231 Davenport Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 121232 Vanmarcke Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 12124 Comparisons of the Three Seismic-Analysis Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 122 Seismic Random-Excitation Fields
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1221 Power Spectral Density of Spatially Varying Ground Acceleration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1222 Several Coherence Models
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12221 FengndashHu Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12222 Harichandran ndashVanmarcke Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12223 LohndashYeh Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12224 OliveirandashHaondashPenzien Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12225 LucondashWong Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12226 QundashWangndashWang Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1223 Generation of Ground Acceleration Power Spectral Density Curves from Acceleration Response Spectrum Curves
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12231 Kaul Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12232 Iteration Scheme
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1224 Seismic Equations of Motion of Long-Span Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1225 Seismic Waves and Their Geometrical Expressions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 123 Pseudoexcitation Method for Structural Random Vibration Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1231 Structures Subjected to Stationary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12311 Single Stationary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12312 Multiple Stationary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1232 Structures Subjected to Nonstationary Random Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12321 Structures Subjected to Uniformly Modulated Evolutionary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 123211 Single Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 123212 Multiple Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12322 Structures Subjected to Nonuniformly Modulated Evolutionary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 123221 Single Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 123222 Multiple Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1233 Precise Integration Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12331 Precise Integration of Exponential Matrices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12332 Particular Solutions and Precise Integration Formulas for Various Forms of Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 123321 Linear Loading Form (HPD-L Form)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 123322 Sinusoidal Loading Form (HPD-S Form)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 123323 Exponentially Decaying Sinusoidal Loading Form (HPD-E Form)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 124 Long-Span Structures Subjected to Stationary Random Ground Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1241 The Solution of Equations of Motion Using the Pseudoexcitation Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1242 Numerical Comparisons with Other Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12421 Song-Hua-Jiang Suspension Bridge
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 124211 All Supports Move Uniformly
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 124212 Wave Passage Effect Is Taken into Account
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 124213 Wave-Passage Effect and Incoherence Effect Are Jointly Taken into Account
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 12422 San Joaquin Concrete Bridge
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 125 Long-Span Structures Subjected to Nonstationary Random Ground Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1251 Modulation Functions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1252 The Formulas for Nonstationary Multiexcitation Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1253 Expected Extreme Values of Nonstationary Random Processes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1254 Numerical Comparisons with the Corresponding Stationary Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 126 Conclusions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Related Titles
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                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Chapter 13 Seismic Qualification of Equipment
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 131 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 132 Distribution Qualification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1321 Drive-Signal Generation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1322 Distribution Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1323 Test Procedures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 133 Seismic Qualification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1331 Stages of Seismic Qualification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1332 Test Preliminaries
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1333 Single-Frequency Testing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1334 Multifrequency Testing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1335 Generation of RRS Specifications
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 53191ch14
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Chapter 14 Human Response to Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 141 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 142 Vibration Excitations on Humans
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1421 Excitation Characteristics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 143 Human Response to Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1431 Vibration Perception
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1432 Frequency Weighting Curve
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1433 Iso-Perception Curves
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1434 Detection Threshold Curve
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 144 Regulation of Human Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1441 Acceptable Vibration Levels in Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1442 Whole-Body Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1443 HandndashArm Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
Page 17: Vibration Monitoring, Testing, and Instrumentationpreview.kingborn.net › 646000 › d1a74678d91943e5ba1d5e... · The MEMS Handbook, Second Edition MEMS: Introduction and Fundamentals

TABLE 11 Typical Operation-Capability Ranges for Various Shaker Types

Shaker Type Typical Operational Capabilities

Frequency Maximum Displacement

(Stroke)

Maximum

Velocity

Maximum

Acceleration

Maximum

Force

Excitation

Waveform

Hydraulic

(electrohydraulic)

Low

(01ndash500 Hz)

High (20 in 50 cm) Intermediate

(50 insec

125 cmsec)

Intermediate

(20 g)

High (100000 lbf

450000 N)

Average flexibility (simple

to complex and random)

Inertial

(counter-rotating mass)

Intermediate

(2ndash50 Hz)

Low (1 in 25 cm) Intermediate

(50 insec

125 cmsec)

Intermediate

(20 g)

Intermediate

(1000 lbf 4500 N)

Sinusoidal only

Electromagnetic

(electrodynamic)

High

(2ndash10000 Hz)

Low (1 in 25 cm) Intermediate

(50 insec

125 cmsec)

High (100 g) Low to intermediate

(450 lbf 2000 N)

High flexibility and accuracy

(simple to complex and

random)

VibrationInstru

mentation

1-5

53191mdash522007mdash

1201mdashSENTHILKUMARmdash246494mdash

CRCndashpp1ndash112

copy 2007 by Taylor amp Francis Group LLC

An idealized performance curve of a shaker

has a constant displacementndashamplitude region a

constant velocityndashamplitude region and a con-

stant accelerationndashamplitude region for low

intermediate and high frequencies respectively

in the operating frequency range Such an ideal

performance curve is shown in Figure 13(a) on a

frequencyndashvelocity plane Logarithmic axes are

used In practice typical shaker performance

curves would be fairly smooth yet nonlinear

curves similar to those shown in Figure 13(b)

As the mass increases the performance curve

compresses Note that the acceleration limit of a

shaker depends on the mass of the test object

(load) Full load corresponds to the heaviest object

that could be tested The ldquono loadrdquo condition

corresponds to a shaker without a test object To

standardize the performance curves they are

usually defined at the rated load of the shaker A

performance curve in the frequencyndashvelocity

plane may be converted to a curve in the

frequencyndashacceleration plane simply by increasing

the slope of the curve by a unit magnitude (ie

20 dbdecade)

Several general observations can be made from

Equation 14 and Equation 15 In the constant-

peak displacement region of the performance

curve the peak velocity increases proportionally

with the excitation frequency and the peak

acceleration increases with the square of the excitation frequency In the constant-peak velocity region

the peak displacement varies inversely with the excitation frequency and the peak acceleration increases

proportionately In the constant-peak acceleration region the peak displacement varies inversely with the

square of the excitation frequency and the peak velocity varies inversely with the excitation frequency

This further explains why rated stroke maximum velocity and maximum acceleration values are not

simultaneously realized

121 Shaker Selection

Vibration testing is accomplished by applying a specified excitation to the test package using a shaker

apparatus and monitoring the response of the test object Test excitation may be represented by its

response spectrum The test requires that the response spectrum of the actual excitation known as the

test response spectrum (TRS) envelops the response spectrum specified for the particular test known as

the required response spectrum (RRS)

A major step in the planning of any vibration testing program is the selection of a proper shaker

(exciter) system for a given test package The three specifications that are of primary importance in

selecting a shaker are the force rating the power rating and the stroke (maximum displacement) rating

Force and power ratings are particularly useful in moderate to high frequency excitations and the stroke

rating is the determining factor for low frequency excitations In this section a procedure is given to

determine conservative estimates for these parameters in a specified test for a given test package

Frequency domain considerations are used here

Stroke

Limit M

ax

Acceleration

MaxVelocity

Peak

Vel

ocity

(cm

s)

01 1 10 100

FullLoad

NoLoad

Frequency (Hz)(a)

Peak

Vel

ocity

(cm

s)

100

10

1

100

10

1

01 1 10 100

FullLoad

NoLoad

Frequency (Hz)(b)

FIGURE 13 Performance curve of a vibration exciter

in the frequencyndashvelocity plane (log) (a) ideal (b)

typical

Vibration Monitoring Testing and Instrumentation1-6

53191mdash522007mdash1201mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

1211 Force Rating

In the frequency domain the (complex) force at the exciter (shaker) head is given by

F frac14 mHethvTHORNasethvTHORN eth16THORNin which v is the excitation frequency variable m is the total mass of the test package including

mounting fixture and attachments asethvTHORN is the Fourier spectrum of the support-location (exciter head)

acceleration and H(v) is frequency response function that takes into account the flexibility and

damping effects (dynamics) of the test package apart from its inertia In the simplified case where the

test package can be represented by a simple oscillator of natural frequency vn and damping ratio by zt

this function becomes

HethvTHORN frac14 1thorn 2jztv=vn=12 ethv=vnTHORN2 thorn 2jztv=vn eth17THORNin which j frac14 ffiffiffiffi

21p

This approximation is adequate for most practical purposes The static weight of the

test object is not included in Equation 16 Most heavy-duty shakers which are typically hydraulic

have static load support systems such as pneumatic cushion arrangements that can exactly balance the

dead load The exciter provides only the dynamic force In cases where shaker directly supports the

gravity load in the vertical test configuration Equation 16 should be modified by adding a term to

represent this weight

A common practice in vibration test applications is to specify the excitation signal by its response

spectrum This is simply the peak response of a simple oscillator expressed as a function of its natural

frequency when its support location is excited by the specified signal Clearly the damping of the simple

oscillator is an added parameter in a response spectrum specification Typical damping ratios ethzrTHORN used inresponse spectra specifications are less than 01 (or 10) It follows that an approximate relationship

between the Fourier spectrum of the support acceleration and its response spectrum is

as frac14 2jzrarethvTHORN eth18THORNThe magnitude larethvTHORNl is the response spectrumEquation 18 substituted into Equation 16 gives

F frac14 mHethvTHORN2jzrarethvTHORN eth19THORNIn view of Equation 17 for test packages having low damping the peak value of H(v) is

approximately 1=eth2jztTHORN this should be used in computing the force rating if the test package has a

resonance within the frequency range of testing On the other hand if the test package is assumed to be

rigid then HethvTHORN oslash 1 A conservative estimate for the force rating is

Fmax frac14 methzr=ztTHORNlarethvTHORNlmax eth110THORNIt should be noted that larethvTHORNlmax is the peak value of the specified (required) response spectrum (RRS)

for acceleration

1212 Power Rating

The exciter head does not develop its maximum force when driven at maximum velocity Output power

is determined by using

p frac14 Refrac12FvsethvTHORN eth111THORNin which vsethvTHORN is the Fourier spectrum of the exciter velocity and Re [ ] denotes the real part of a complex

function Note that as frac14 jvvs Substituting Equation 16 and Equation 18 into Equation 111 gives

p frac14 eth4mz2r =vTHORNRefrac12jHethvTHORNa2r ethvTHORN eth112THORNIt follows that a conservative estimate for the power rating is

pmax frac14 2methz2r =ztTHORNfrac12larethvTHORNl2=v max eth113THORN

Vibration Instrumentation 1-7

53191mdash522007mdash1201mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

Representative segments of typical acceleration RRS curves have slope n as given by

a frac14 k1vn eth114THORN

It should be clear from Equation 113 that the maximum output power is given by

pmax frac14 k2v2n21 eth115THORN

This is an increasing function for n 1=2 and a decreasing function for n 1=2 It follows that the power

rating corresponds to the highest point of contact between the acceleration RRS curve and a line of slope

equal to 12 A similar relationship may be derived if velocity RRS curves (having slopes n2 1) are used

1213 Stroke Rating

From Equation 18 it should be clear that the Fourier spectrum xs of the exciter displacement time

history can be expressed as

xs frac14 2zrarethvTHORN=jv2 eth116THORNAn estimate for stroke rating is

xmax frac14 2zrfrac12larethvTHORNl=v2 max eth117THORNThis is of the form

xmax frac14 kvn22 eth118THORNIt follows that the stroke rating corresponds to the highest point of contact between the acceleration

RRS curve and a line of slope equal to two

Example 11

A test package of overall mass 100 kg is to be

subjected to dynamic excitation represented by the

acceleration RRS (at 5 damping) as shown in

Figure 14 The estimated damping of the test

package is 7 The test package is known to have a

resonance within the frequency range of the

specified test Determine the exciter specifications

for the test

Solution

From the development presented in the previous

section it is clear that the point F (or P) in

Figure 14 corresponds to the force and output

power ratings and the point S corresponds to

the stroke rating The co-ordinates of these

critical points are F P frac14 eth42 Hz 40 gTHORN and S frac14 eth08 Hz 075 gTHORN Equation 110 gives the force

rating as

Fmax frac14 100 pound eth005=007THORN pound 40 pound 981 N frac14 2803 N

Equation 113 gives the power rating as

pmax frac14 2 pound 100 pound eth0052=007THORN pound frac12eth40 pound 981THORN2=42 pound 2p watts frac14 417 W

Equation 117 gives the stroke rating as

xmax frac14 2 pound 005 pound frac12eth075 pound 98THORN=eth08 pound 2pTHORN2 m frac14 3 cm

Acc

eler

atio

n(g

)

Con

stan

t Dis

plac

emen

t

Constant Velo

city

Frequency (Hz)

S

FP

0101

10 10 100

10

10

FIGURE 14 Test excitation specified by an accelera-

tion RRS (5 damping)

Vibration Monitoring Testing and Instrumentation1-8

53191mdash522007mdash1201mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

1214 Hydraulic Shakers

A typical hydraulic shaker consists of a piston-cylinder arrangement (also called a ram) a servo-valve a

fluid pump and a driving electric motor Hydraulic fluid (oil) is pressurized (typical operating pressure

4000 psi) and pumped into the cylinder through a servo-valve by means of a pump that is driven by an

electric motor (typical power 150 hp) The flow (typical rate 100 galmin) that enters the cylinder is

controlled (modulated) by the servo-valve which in effect controls the resulting piston (ram) motion

A typical servo-valve consists of a two-stage spool valve which provides a pressure difference and a

controlled (modulated) flow to the piston which sets it in motion

The servo-valve itself is moved by means of a linear torque motor which is driven by the excitation-

input signal (electrical) A primary function of the servo-valve is to provide a stabilizing feedback to the

ram In this respect the servo-valve complements the main control system of the test setup The ram is

coupled to the shaker table by means of a link with some flexibility The cylinder frame is mounted on the

support foundation with swivel joints This allows for some angular and lateral misalignment which

might be caused primarily by test-object dynamics as the table moves

Two-degree-of-freedom (Two-DoF) testing requires two independent sets of actuators and three-DoF

testing requires three independent actuator sets Each independent actuator set can consist of several

actuators operated in parallel using the same pump and the same excitation-input signal to the torque

motors

If the test table is directly supported on the vertical actuators they must withstand the total dead

weight (ie the weight of the test table the test object the mounting fixtures and the instrumentation)

This is requirement is usually prevented by providing a pressurized air cushion in the gap between the

test table and the foundation walls Air should be pressurized so as to balance the total dead weight

exactly (typical required gage pressure 3 psi)

Figure 15(a) shows the basic components of a typical hydraulic shaker The corresponding

operational block diagram is shown in Figure 15(b) It is desirable to locate the actuators in a pit in the

test laboratory so that the test tabletop is flushed with the test laboratory floor under no-load conditions

This minimizes the effort required to place the test object on the test table Otherwise the test object has

to be lifted onto the test table with a forklift Also installation of an aircushion to support the system

dead weight is difficult under these circumstances of elevated mounting

Hydraulic actuators are most suitable for heavy load testing and are widely used in industrial and civil

engineering applications They canbeoperated at very low frequencies (almost direct current [DC]) aswell

as at intermediate frequencies (see Table 11) Large displacements (stroke) are possible at low frequencies

Hydraulic shakers have the advantage of providing high flexibility of operation during the test their

capabilities include variable-force and constant-force testing and wide-band random-input testing The

velocity and acceleration capabilities of hydraulic shakers are moderate Although any general excitation-

input motion (for example sine wave sine beat wide-band random) can be used in hydraulic shakers

faithful reproduction of these signals is virtually impossible at high frequencies because of distortion and

higher-order harmonics introduced by the high noise levels that are common in hydraulic systems This

is only a minor drawback in heavy-duty intermediate-frequency applications Dynamic interactions are

reduced through feedback control

1215 Inertial Shakers

In inertial shakers or ldquomechanical excitersrdquo the force that causes the shaker-table motion is generated by

inertia forces (accelerating masses) Counter-rotating-mass inertial shakers are typical in this category

To understand their principle of operation consider two equal masses rotating in opposite directions at

the same angular speed v and in the same circle of radius r (see Figure 16) This produces a resultant

force equal to 2mv2r cos vt in a fixed direction (the direction of symmetry of the two rotating arms)

Consequently a sinusoidal force with a frequency of v and an amplitude proportional to v2 is generated

This reaction force is applied to the shaker table

Figure 17 shows a sketch of a typical counter-rotating-mass inertial shaker It consists of two identical

rods rotating at the same speed in opposite directions Each rod has a series of slots in which to

Vibration Instrumentation 1-9

53191mdash522007mdash1201mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

place weights In this manner the magnitude of

the eccentric mass can be varied to achieve various

force capabilities The rods are driven by a

variable-speed electric motor through a gear

mechanism that usually provides several speed

ratios A speed ratio is selected depending on the

required test-frequency range The whole system is

symmetrically supported on a carriage that is

directly connected to the test table The test object

is mounted on the test table The preferred

mounting configuration is horizontal so that the

excitation force is applied to the test object in a

horizontal direction In this configuration there

are no variable gravity moments (weight pounddistance to center of gravity) acting on the drive

mechanism Figure 17 shows the vertical con-

figuration In dynamic testing of large structures

the carriage can be mounted directly on the

structure at a location where the excitation force

should be applied By incorporating two pairs of

counter-rotating masses it is possible to generate

test moments as well as test forces

FIGURE 15 A typical hydraulic shaker arrangement (a) schematic diagram (b) operational block diagram

m m

2mw2r cos wt

wtw w

wt

FIGURE 16 Principle of operation of a counter-

rotating-mass inertial shaker

Vibration Monitoring Testing and Instrumentation1-10

53191mdash522007mdash1201mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

Reaction-type shakers driven by inertia are widely used for the prototype testing of civil engineering

structures Their first application dates back to 1935 Inertial shakers are capable of producing

intermediate excitation forces The force generated is limited by the strength of the carriage frame The

frequency range of operation and the maximum velocity and acceleration capabilities are also

intermediate for inertial shakers whereas the maximum displacement capability is typically low A major

limitation of inertial shakers is that their excitation force is exclusively sinusoidal and that the force

amplitude is directly proportional to the square of the excitation frequency As a result complex and

random excitation testing constant-force testing (for example transmissibility tests and constant-force

sine-sweep tests) and flexibility to vary the force amplitude or the displacement amplitude during a test

are not generally feasible with this type of shakers Excitation frequency and amplitude can be varied

during testing however by incorporating a variable-speed drive for the motor The sinusoidal excitation

generated by inertial shakers is virtually undistorted which gives them an advantage over the other types

of shakers when used in sine-dwell and sine-sweep tests Small portable shakers with low-force capability

are available for use in on-site testing

1216 Electromagnetic Shakers

In electromagnetic shakers or ldquoelectrodynamic excitersrdquo the motion is generated using the principle of

operation of an electric motor Specifically the excitation force is produced when a variable excitation

signal (electrical) is passed through a moving coil placed in a magnetic field

The components of a commercial electromagnetic shaker are shown in Figure 18 A steady magnetic

field is generated by a stationary electromagnet that consists of field coils wound on a ferromagnetic base

that is rigidly attached to a protective shell structure The shaker head has a coil wound around it When

the excitation electrical signal is passed through this drive coil the shaker head which is supported on

flexure mounts will be set in motion The shaker head consists of the test table on which the test object

is mounted Shakers with interchangeable heads are available The choice of appropriate shaker head is

based on the geometry and mounting features of the test object The shaker head can be turned to

different angles by means of a swivel joint In this manner different directions of excitation (in biaxial

and triaxial testing) can be obtained

FIGURE 17 Sketch of a counter-rotating-mass inertial shaker

Vibration Instrumentation 1-11

53191mdash522007mdash1202mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

122 Dynamics of Electromagnetic Shakers

Consider a single axis electromagnetic shaker (Figure 18) with a test object having a single natural

frequency of importance within the test frequency range The dynamic interactions between the shaker

and the test object give rise to two significant natural frequencies (and correspondingly two significant

resonances) These appear as peaks in the frequency response curve of the test setup Furthermore the

natural frequency (resonance) of the test package alone causes a ldquotroughrdquo or depression (antiresonance)

in the frequency response curve of the overall test setup To explain this characteristic consider the

dynamic model shown in Figure 19 The following mechanical parameters are defined for

Figure 19(a) m k and b are the mass stiffness and equivalent viscous damping constant respectively

of the test package and me ke and be are the corresponding parameters of the exciter (shaker) Also in

the equivalent electrical circuit of the shaker head as shown in Figure 19(b) the following electrical

parameters are defined Re and Le are the resistance and (leakage) inductance and kb is the back

electromotive force (back emf) of the linear motor Assuming that the gravitational forces are supported

FIGURE 18 Schematic sectional view of a typical electromagnetic shaker manufactured by Bruel and Kjaer

Denmark

Vibration Monitoring Testing and Instrumentation1-12

53191mdash522007mdash1202mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

by the static deflections of the flexible elements and that the displacements are measured from the static

equilibrium position we have the following system equations

Test object meuroy frac14 2kethy2 yeTHORN2 beth_y2 _yeTHORN eth119THORNShaker head me euroye frac14 fe thorn kethy2 yeTHORN thorn beth_y2 _yeTHORN2 key 2 be _ye eth120THORN

Electrical Lediedt

thorn Reie thorn kb _ye frac14 vethtTHORN eth121THORN

The electromagnetic force fe generated in the shaker head is a result of the interaction of the magnetic

field generated by the current ie with coil of the moving shaker head and the constant magnetic field

(stator) in which the head coil is located Here we have

fe frac14 kbie eth122THORNNote that v(t) is the voltage signal that is applied by the amplifier to the shaker coil ye is the displacement

of the shaker head and y is the displacement response of the test package

It is assumed that kb has consistent electrical and mechanical units (Vmsec and NA) Usually

the electrical time constant of the shaker is quite small compared with the primarily mechanical

time constants of the shaker and the test package In such cases the Ledie=dt term in Equation 121 may

be neglected Consequently the equations from Equation 119 through Equation 122 may be

expressed in the Laplace (frequency) domain with the Laplace variable s taking the place of the derivative

d=dt as

ethms2 thorn bsthorn kTHORNy frac14 ethbsthorn kTHORNye eth123THORN

FIGURE 19 Dynamic models of an electromagnetic shaker and a flexible test package (a) mechanical model

(b) electrical model

Vibration Instrumentation 1-13

53191mdash522007mdash1202mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

frac12mes2 thorn ethbthorn beTHORNsthorn ethkthorn keTHORN ye frac14 ethbsthorn kTHORNy thorn kb

Rev2

k2bs

Reye eth124THORN

It follows that the transfer function of the shaker head motion with respect to the excitation voltage is

given by

yevfrac14 kb

Re

DethsTHORNDdethsTHORN eth125THORN

where DethsTHORN is the characteristic function of the primary dynamics of the test object

DethsTHORN frac14 ms2 thorn bsthorn k eth126THORN

and DdethsTHORN is the characteristic function of the primary dynamic interactions between the shaker and thetest object

DcethsTHORN frac14 mmes4 thorn frac12methbe thorn bthorn boTHORN thornmeb s

3 thorn frac12methke thorn kTHORN thornmekthorn bethbe thorn boTHORN s2thorn frac12bke thorn ethbe thorn boTHORNk sthorn kke

eth127THORN

where

bo frac14 k2bRe

eth128THORN

It is clear that under low damping conditions DdethsTHORN will produce two resonances as it is fourth order in sand similarly DethsTHORN will produce one antiresonance (trough) corresponding to the resonance of the testobject Note that in the frequency domain s frac14 jv and hence the frequency response function given by

Equation 125 is in fact

yevfrac14 kb

Rb

DethjvTHORNDdethjvTHORN eth129THORN

The magnitude of this frequency response function for a typical test system is sketched in Figure 110

Note that this curve is for the ldquoopen-looprdquo case where there is no feedback from the shaker controller

In practice the shaker controller will be able

to compensate for the resonances and anti-

resonances to some degree depending on its

effectiveness

The main advantages of electromagnetic

shakers are their high frequency range of

operation their high degree of operating flexi-

bility and the high level of accuracy of the

generated shaker motion Faithful reproduction

of complex excitations is possible because of the

advanced electronics and control systems used in

this type of shakers Electromagnetic shakers are

not suitable for heavy-duty applications (large test

objects) however High test-input accelerations

are possible at high frequencies when electromag-

netic shakers are used but their displacement and

velocity capabilities are limited to low or

intermediate values (see Table 11)

100

10

1 10 100Excitation Frequency (Hz)

Antiresonance

Resonance

Shak

erD

ispl

acem

entM

agni

tude

Resonance

1000

FIGURE 110 Frequency response curve of a typical

electromagnetic shaker with a test object

Vibration Monitoring Testing and Instrumentation1-14

53191mdash522007mdash1202mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

1221 Transient Exciters

Other varieties of exciters are commonly used in

transient-type vibration testing In these tests

either an impulsive force or an initial excitation is

applied to the test object and the resulting

response is monitored The excitations and the

responses are ldquotransientrdquo in this case Hammer

test drop tests and pluck tests fall into this

category For example a hammer test may be

conducted by hitting the object with an instru-

mented hammer and then measuring the response

of the object The hammer has a force sensor at its

tip as sketched in Figure 111 A piezoelectric or

strain-gage type force sensor may be used More

sophisticated hammers have impedance heads in

place of force sensors An impedance head

measures force and acceleration simultaneously

The results of a hammer test will depend on many

factors for example the dynamics of the hammer

body how firmly the hammer is held during the

impact how quickly the impact is applied and

whether there are multiple impacts

13 Control System

The two primary functions of the shaker control system in vibration testing are (1) to guarantee that the

specified excitation is applied to the test object and (2) to ensure that the dynamic stability (motion

constraints) of the test setup is preserved An operational block diagram illustrating these control

functions is given in Figure 112 The reference input to the control system represents the desired

excitation force that should be applied to the test object In the absence of any control however the force

reaching the test object will be distorted primarily because of (1) dynamic interactions and

nonlinearities of the shaker the test table the mounting fixtures the auxiliary instruments and the test

object itself (2) noise and errors in the signal generator amplifiers filters and other equipment and (3)

external loads and disturbances acting on the test object and other components (for example external

restraints aerodynamic forces friction) To compensate for these distorting factors response

measurements (displacements velocities acceleration and so on) are made at various locations in the

test setup and are used to control the system dynamics In particular the responses of the shaker the test

table and the test object are measured These responses are used to compare the actual excitation felt by

FIGURE 111 An instrumented hammer used in bump

tests or hammer tests

ExcitationInput

(Reference)

Feedback Paths

DriveSignal

ShakerResponse

TestTable

TestObject

Test ObjectResponse

Test TableResponseExciter

(Shaker)(Ram)

Controllerand

Amplifier

FIGURE 112 Operational block diagram illustrating a general shaker control system

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the test object at the shaker interface with the desired (specified) input The drive signal to the shaker is

modified depending on the error that is present

Two types of control are commonly employed in shaker apparatus simple manual control and

complex automatic control Manual control normally consists of simple open-loop trial-and-error

methods of manual adjustments (or calibration) of the control equipment to obtain a desired dynamic

response The actual response is usually monitored (on an oscilloscope or frequency analyzer screen for

example) during manual-control operations The pretest adjustments in manual control can be very

time-consuming as a result the test object might be subjected to overtesting which could produce

cumulative damage is undesirable and could defeat the test purpose Furthermore the calibration

procedure for the experimental setup must be repeated for each new test object

The disadvantages ofmanual control suggest that automatic control is desirable in complex test schemes

in which high accuracy of testing is desired The first step of automatic control involves automatic

measurement of the system response using control sensors and transducers The measurement is then fed

back into the control system which instantaneously determines the best drive signal to actuate the shaker

in order to get the desired excitation This may be done by either analog or digital methods

Primitive control systems require an accurate mathematical description of the test object This

dependency of the control system on the knowledge of test-object dynamics is clearly undesirable

Performance of a good control system should not be considerably affected by the dynamic interactions

and nonlinearities of the test object or by the nature of the excitation Proper selection of feedback signals

and control-system components can reduce such effects and will make the system robust

In the response-spectrum method of vibration testing it is customary to use displacement control at

low frequencies velocity control at intermediate frequency and acceleration control at high frequencies

This necessitates feedback of displacement velocity and acceleration responses Generally however the

most important feedback is the velocity feedback In sine-sweep tests the shaker velocity must change

steadily over the frequency band of interest In particular the velocity control must be precise near the

resonances of the test object Velocity (speed) feedback has a stabilizing effect on the dynamics which is

desirable This effect is particularly useful in ensuring stability in motion when testing is done near

resonances of lightly damped test objects On the contrary displacement (position) feedback can have a

destabilizing effect on some systems particularly when high feedback gains are used

The controller usually consists of various instruments equipment and computation hardware and

software Often the functions of the data-acquisition and processing system overlap with those of the

controller to some extent As an example consider the digital-controller of vibration testing apparatus

First the responses are measured through sensors (and transducers) filtered and amplified

(conditioned) These data channels may be passed through a multiplexer whose purpose is to select

one data channel at a time for processing Most modern data acquisition hardware does not need a

separate multiplexer to handle multiple signals The analog data are converted into digital data using

analog-to-digital converters (ADCs) The resulting sampled data are stored on a disk or as a block data in

the computer memory The reference input signal (typically a signal recorded on an FM tape) is also

sampled (if it is not already in the digital form) using an ADC and fed into the computer Digital

processing is done on the reference signal and the response data with the objective of computing the

command signal to drive the shaker The digital command signal is converted into an analog signal using

a digital-to-analog converter (DAC) and amplified (conditioned) before it is used to drive the exciter

The nature of the control components depends to a large extent on the nature and objectives of the

particular test to be conducted Some of the basic components in a shaker controller are described in

the following subsections

131 Components of a Shaker Controller

1311 Compressor

A compressor circuit is incorporated in automatic excitation control devices to control the excitation-

input level automatically The level of control depends on the feedback signal from a control sensor and

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the specified (reference) excitation signal Usually the compressor circuit is included in the excitation-

signal generator (for example in a sine generator) The control by this means may be done on the basis of

a single-frequency component (eg the fundamental frequency)

1312 Equalizer (Spectrum Shaper)

Random-signal equalizers are used to shape the spectrum of a random signal in a desired manner In

essence and equalizer consists of a bank of narrow-band filters (for example 80 filters) in parallel over

the operating frequency range By passing the signal through each filter the spectral density (or the mean

square value) of the signal in that narrow frequency band (for example each one-third-octave band) is

determined This is compared with the desired spectral level and automatic adjustment is made in that

filter in case there is an error In some systems response-spectrum analysis is made in place of power

spectral density analysis In that case the equalizer consists of a bank of simple oscillators whose

resonant frequencies are distributed over the operating frequency range of the equalizer The feedback

signal is passed through each oscillator and the peak value of its output is determined This value is

compared with the desired response spectrum value at that frequency If there is an error automatic gain

adjustment is made in the appropriate excitation signal components

Random-noise equalizers are used in conjunction with random signal generators They receive

feedback signals from the control sensors In some digital control systems there are algorithms (software)

that are used to iteratively converge the spectrum of the excitation signal felt by the test object into the

desired spectrum

1313 Tracking Filter

Many vibration tests are based on single-frequency excitations In such cases the control functions

should be performed on the basis of the amplitudes of the fundamental-frequency component of the

signal A tracking filter is simply a frequency-tuned band-pass filter It automatically tunes the center

frequency of its very narrow-band-pass filter to the frequency of a carrier signal Then when a noisy

signal is passed through the tuned filter the output of the filter will be the required fundamental

frequency component in the signal Tracking filters also are useful in obtaining amplitudendashfrequency

plots using an XndashY plotter In such cases the frequency value comes from the signal generator (sweep

oscillator) which produces the carrier signal to the tracking filter The tracking filter then determines the

corresponding amplitude of a signal that is fed into it Most tracking filters have dual channels so that two

signals can be handled (tracked) simultaneously

1314 Excitation Controller (Amplitude Servo-Monitor)

An excitation controller is typically an integral part of the signal generator It can be set so that automatic

sweep between two frequency limits can be performed at a selected sweep rate (linear or logarithmic)

More advanced excitation controllers have the capability of an automatic switch-over between constant-

displacement constant-velocity and constant-acceleration excitation-input control at specified

frequencies over the sweep frequency interval Consequently integrator circuits should be present

within the excitation controller unit to determine velocities and displacements from acceleration signals

Sometimes integration is performed by a separate unit called a vibration meter This unit also offers

the operator the capability of selecting the desired level of each signal (acceleration velocity or

displacement) There is an automatic cut-off level for large displacement values that could result from

noise in acceleration signals A compressor is also a subcomponent of the excitation controller The

complete unit is sometimes known as an amplitude servo-monitor

132 Signal-Generating Equipment

Shakers are force-generating devices that are operated using drive (excitation) signals generated from a

source The excitation-signal source is known as the signal generator Three major types of signal

generators are used in vibration testing applications (1) oscillators (2) random-signal generators and

(3) storage devices In some units oscillators and random-signal generators are combined We shall

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discuss these two generators separately however because of their difference in function It also should be

noted that almost any digital signal (deterministic or random) can be generated by a digital computer

using a suitable computer program the signal eventually can be passed through a DAC to obtain

the corresponding analog signal These lsquodigitalrsquo signal generators along with analog sources such as

magnetic tape players (FM) are classified into the category of storage devices

The dynamic range of equipment is the ratio of the maximum and minimum output levels (expressed

in decibels) at which it is capable of operating without significant error This is an important specification

for many types of equipment particularly for signal-generating devices The output level of the signal

generator should be set to a value within its dynamic range

1321 Oscillators

Oscillators are essentially single-frequency generators Typically sine signals are generated but other

waveforms (such as rectangular and triangular pulses) are also available in most oscillators Normally

an oscillator has two modes of operation (1) sweeping up and down between two frequency limits and

(2) dwelling at a specified frequency In the sweep operation the sweep rate should be specified This can

be done either on a linear scale (Hzmin) or on a logarithmic scale (octavesmin) In the dwell operation

the frequency points (or intervals) should be specified In either case a desired signal level can be chosen

using the gain-control knob An oscillator that is operated exclusively in the sweep mode is called a sweep

oscillator

The early generation of oscillators employed variable inductor-capacitor types of electronic circuits to

generate signals oscillating at a desired frequency The oscillator is tuned to the required frequency by

varying the capacitance or inductance parameters A DC voltage is applied to energize the capacitor

and to obtain the desired oscillating voltage signal which subsequently is amplified and conditioned

Modern oscillators use operational amplifier circuits along with resistor capacitor and semiconductor

(SC) elements Also common are crystal (quartz) parallel-resonance oscillators used to generate voltage

signals accurately at a fixed frequency The circuit is activated using a DC-voltage source Other

frequencies of interest are obtained by passing this high-frequency signal through a frequency converter

The signal is then conditioned (amplified and filtered) Required shaping (for example rectangular

pulse) is obtained using a shape circuit Finally the required signal level is obtained by passing the

resulting signal through a variable-gain amplifier A block diagram of an oscillator illustrating various

stages in the generation of a periodic signal is given in Figure 113

A typical oscillator offers a choice of several (typically six) linear and logarithmic frequency ranges and

a sizable level of control capability (for example 80 dB) Upper and lower frequency limits in a sweep can

be preset on the front panel to any of the available frequency ranges Sweep-rate settings are continuously

DC Voltage

Oscillator

FrequencySpecification

FrequencyConverter

FilterAmplifier

ShaperPeriodicSignal

FrequencyCounter

Fixed-FrequencySignal

Variable-GainOutput

Amplifier

SignalSpecification

LevelSpecification

FIGURE 113 Block diagram of an oscillator-type signal generator

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  • 53191fm
    • Vibration Monitoring Testing and Instrumentation
      • Preface
      • Acknowledgments
      • Editor-in-Chief
      • Contributors
      • Contents
      • Related Titles
          • 53191ch1
            • Table of Contents
            • Chapter 1 Vibration Instrumentation
              • Summary
              • 11 Introduction
              • 12 Vibration Exciters
                • 121 Shaker Selection
                  • 1211 Force Rating
                  • 1212 Power Rating
                  • 1213 Stroke Rating
                  • 1214 Hydraulic Shakers
                  • 1215 Inertial Shakers
                  • 1216 Electromagnetic Shakers
                    • 122 Dynamics of Electromagnetic Shakers
                      • 1221 Transient Exciters
                          • 13 Control System
                            • 131 Components of a Shaker Controller
                              • 1311 Compressor
                              • 1312 Equalizer (Spectrum Shaper)
                              • 1313 Tracking Filter
                              • 1314 Excitation Controller (Amplitude Servo-Monitor)
                                • 132 Signal-Generating Equipment
                                  • 1321 Oscillators
                                  • 1322 Random Signal Generators
                                  • 1323 Tape Players
                                  • 1324 Data Processing
                                      • 14 Performance Specification
                                        • 141 Parameters for Performance Specification
                                          • 1411 Time-Domain Specifications
                                          • 1412 Frequency-Domain Specifications
                                            • 142 Linearity
                                            • 143 Instrument Ratings
                                              • 1431 Rating Parameters
                                                • 144 Accuracy and Precision
                                                  • 15 Motion Sensors and Transducers
                                                    • 151 Potentiometer
                                                      • 1511 Potentiometer Resolution
                                                      • 1512 Optical Potentiometer
                                                        • 152 Variable-Inductance Transducers
                                                          • 1521 Mutual-Induction Transducers
                                                          • 1522 Linear-Variable Differential Transformer
                                                          • 1523 Signal Conditioning
                                                            • 153 Mutual-Induction Proximity Sensor
                                                            • 154 Selfinduction Transducers
                                                            • 155 Permanent-Magnet Transducers
                                                            • 156 Alternating Current Permanent-Magnet Tachometer
                                                            • 157 Alternating Current Induction Tachometer
                                                            • 158 Eddy Current Transducers
                                                            • 159 Variable-Capacitance Transducers
                                                              • 1591 Capacitive Displacement Sensors
                                                              • 1592 Capacitive Angular Velocity Sensor
                                                              • 1593 Capacitance Bridge Circuit
                                                                • 1510 Piezoelectric Transducers
                                                                  • 15101 Sensitivity
                                                                  • 15102 Piezoelectric Accelerometer
                                                                  • 15103 Charge Amplifier
                                                                      • 16 Torque Force and Other Sensors
                                                                        • 161 Strain Gage Sensors
                                                                          • 1611 Equations for Strain Gage Measurements
                                                                          • 1612 Bridge Sensitivity
                                                                          • 1613 The Bridge Constant
                                                                          • 1614 The Calibration Constant
                                                                          • 1615 Data Acquisition
                                                                          • 1616 Accuracy Considerations
                                                                          • 1617 Semiconductor Strain Gages
                                                                          • 1618 Force and Torque Sensors
                                                                          • 1619 Strain Gage Torque Sensors
                                                                          • 16110 Deflection Torque Sensors
                                                                          • 16111 Variable-Reluctance Torque Sensor
                                                                          • 16112 Reaction Torque Sensors
                                                                            • 162 Miscellaneous Sensors
                                                                              • 1621 Stroboscope
                                                                              • 1622 Fiber Optic Sensors and Lasers
                                                                              • 1623 Fiber-Optic Gyroscope
                                                                              • 1624 Laser Doppler Interferometer
                                                                              • 1625 Ultrasonic Sensors
                                                                              • 1626 Gyroscopic Sensors
                                                                                  • References
                                                                                  • Appendix 1A Virtual Instrumentation for Data Acquisition Analysis and Presentation
                                                                                    • Summary
                                                                                    • List of Abbreviations
                                                                                    • 1A1 Dynamic Signals
                                                                                      • 1A11 Acquiring and Simulating Dynamic Signals
                                                                                        • 1A111 Aliasing
                                                                                        • 1A112 Time Continuity
                                                                                            • 1A2 Measurement Configuration Considerations
                                                                                              • 1A21 Input Signal Considerations
                                                                                                • 1A211 Input Pseudodifferential and Differential Configuration
                                                                                                • 1A212 Gain
                                                                                                • 1A213 Input Coupling
                                                                                                • 1A214 Integrated Electronic Piezoelectric Excitation
                                                                                                • 1A215 Nyquist Frequency and Bandwidth
                                                                                                • 1A216 Analog-to-Digital Conversion
                                                                                                • 1A217 Antialias Filters
                                                                                                • 1A218 Input Filter Delay
                                                                                                • 1A219 Overload Detection
                                                                                                  • 1A22 Output Signal Considerations
                                                                                                    • 1A221 Output Pseudodifferential and Differential Configuration
                                                                                                    • 1A222 Attenuation
                                                                                                    • 1A223 Digital-to-Analog Conversion
                                                                                                    • 1A224 Anti-imaging and Interpolation Filters
                                                                                                    • 1A225 Output Filter Delay
                                                                                                        • 1A3 Scaling and Calibration
                                                                                                          • 1A31 Scaling to Engineering Units
                                                                                                          • 1A32 Performing System Calibration
                                                                                                            • 1A321 Propagation Delay Calibration
                                                                                                                • 1A4 Limit Testing Analysis
                                                                                                                  • 1A41 Limit Testing Overview
                                                                                                                  • 1A42 Using the SVT Limit Testing VI
                                                                                                                    • 1A5 Integration
                                                                                                                      • 1A51 Introduction to Integration
                                                                                                                      • 1A52 Implementing Integration
                                                                                                                        • 1A521 Challenges when Integrating Vibration Data
                                                                                                                          • 1A53 Time-Domain Integration
                                                                                                                            • 1A531 Single-Shot Acquisition and Integration
                                                                                                                            • 1A532 Continuous Acquisition and Integration
                                                                                                                              • 1A54 Frequency-Domain Integration
                                                                                                                                • 1A6 Vibration-Level Measurements
                                                                                                                                  • 1A61 Measuring the Root Mean Square Level
                                                                                                                                    • 1A611 Single-Shot Buffered Acquisition
                                                                                                                                    • 1A612 Continuous Signal Acquisition
                                                                                                                                      • 1A62 Performing a Running RMS Level Measurement
                                                                                                                                      • 1A63 Computing the Peak Level
                                                                                                                                      • 1A64 Computing the Crest Factor
                                                                                                                                        • 1A7 Frequency Analysis
                                                                                                                                          • 1A71 FFT Fundamentals
                                                                                                                                            • 1A711 Number of Samples
                                                                                                                                            • 1A712 Frequency Resolution
                                                                                                                                            • 1A713 Maximum Resolvable Frequency
                                                                                                                                            • 1A714 Minimum Resolvable Frequency
                                                                                                                                            • 1A715 Number of Spectral Lines
                                                                                                                                            • 1A716 Relationship between Time-Domain and Frequency-Domain Specifications and Parameters
                                                                                                                                              • 1A72 Increasing Frequency Resolution
                                                                                                                                                • 1A721 Zoom FFT Analysis
                                                                                                                                                • 1A722 Frequency Resolution of the Zoom FFT VIs
                                                                                                                                                • 1A723 Zoom Measurement
                                                                                                                                                • 1A724 Zoom Settings
                                                                                                                                                • 1A725 Subset Analysis
                                                                                                                                                    • 1A8 Transient Analysis
                                                                                                                                                      • 1A81 Transient Analysis with the Sound and Vibration Toolkit
                                                                                                                                                      • 1A82 Performing an STFT vs Time
                                                                                                                                                        • 1A821 Selecting the FFT Block Size
                                                                                                                                                        • 1A822 Overlapping
                                                                                                                                                        • 1A823 Using the SVT STFT vs Time VI
                                                                                                                                                          • 1A83 Performing an STFT vs Rotational Speed
                                                                                                                                                            • 1A831 Converting the Pulse Train to Rotational Speed
                                                                                                                                                            • 1A832 STFT vs RPM
                                                                                                                                                              • 1A84 Measuring a Shock Response Spectrum
                                                                                                                                                                • 1A9 Waterfall Display
                                                                                                                                                                  • 1A91 Using the Display VIs
                                                                                                                                                                    • 1A911 Initializing the Display
                                                                                                                                                                    • 1A912 Sending Data to the Display
                                                                                                                                                                    • 1A913 Waterfall Display for Frequency Analysis
                                                                                                                                                                    • 1A914 Waterfall Display for Transient Analysis
                                                                                                                                                                    • 1A915 Waterfall Display for Octave Spectra
                                                                                                                                                                        • 1A10 Swept-Sine Measurements
                                                                                                                                                                          • 1A101 Swept-Sine Overview
                                                                                                                                                                          • 1A102 Choosing Swept-Sine vs FFT Measurements
                                                                                                                                                                          • 1A103 Taking a Swept-Sine Measurement
                                                                                                                                                                          • 1A104 Swept-Sine Measurement Example
                                                                                                                                                                              • Bibliography
                                                                                                                                                                              • Related Titles
                                                                                                                                                                                  • 53191ch2
                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                    • Chapter 2 Signal Conditioning and Modification
                                                                                                                                                                                      • Summary
                                                                                                                                                                                      • 21 Introduction
                                                                                                                                                                                      • 22 Amplifiers
                                                                                                                                                                                        • 221 Operational Amplifier
                                                                                                                                                                                        • 222 Use of Feedback in Opamp
                                                                                                                                                                                        • 223 Voltage Current and Power Amplifiers
                                                                                                                                                                                          • 2231 Charge Amplifiers
                                                                                                                                                                                            • 224 Instrumentation Amplifiers
                                                                                                                                                                                              • 2241 Differential Amplifier
                                                                                                                                                                                              • 2242 Common Mode
                                                                                                                                                                                                • 225 Amplifier Performance Ratings
                                                                                                                                                                                                  • 2251 Common-Mode Rejection Ratio
                                                                                                                                                                                                    • 226 Component Interconnection
                                                                                                                                                                                                      • 2261 Impedance Characteristics
                                                                                                                                                                                                      • 2262 Cascade Connection of Devices
                                                                                                                                                                                                      • 2263 AC-Coupled Ampliers
                                                                                                                                                                                                          • 23 Analog Filters
                                                                                                                                                                                                            • 231 Passive Filters and Active Filters
                                                                                                                                                                                                              • 2311 Number of Poles
                                                                                                                                                                                                                • 232 Low-Pass Filters
                                                                                                                                                                                                                  • 2321 Low-Pass Butterworth Filter
                                                                                                                                                                                                                    • 233 High-Pass Filters
                                                                                                                                                                                                                    • 234 Band-Pass Filters
                                                                                                                                                                                                                      • 2341 Resonance-Type Band-Pass Filters
                                                                                                                                                                                                                        • 235 Band-Reject Filters
                                                                                                                                                                                                                          • 24 Modulators and Demodulators
                                                                                                                                                                                                                            • 241 Amplitude Modulation
                                                                                                                                                                                                                              • 2411 Modulation Theorem
                                                                                                                                                                                                                              • 2412 Side Frequencies and Side Bands
                                                                                                                                                                                                                                • 242 Application of Amplitude Modulation
                                                                                                                                                                                                                                  • 2421 Fault Detection and Diagnosis
                                                                                                                                                                                                                                    • 243 Demodulation
                                                                                                                                                                                                                                      • 25 Analog ndashDigital Conversion
                                                                                                                                                                                                                                        • 251 Digital-to-Analog Conversion
                                                                                                                                                                                                                                          • 2511 DAC Error Sources
                                                                                                                                                                                                                                            • 252 Analog-to-Digital Conversion
                                                                                                                                                                                                                                            • 253 Analog-to-Digital Converter Performance Characteristics
                                                                                                                                                                                                                                              • 2531 Resolution and Quantization Error
                                                                                                                                                                                                                                              • 2532 Monotonicity Nonlinearity and Offset Error
                                                                                                                                                                                                                                              • 2533 Analog-to-Digital Converter Conversion Rate
                                                                                                                                                                                                                                                • 254 Sample-and-Hold Circuitry
                                                                                                                                                                                                                                                • 255 Digital Filters
                                                                                                                                                                                                                                                  • 2551 Software Implementation and Hardware Implementation
                                                                                                                                                                                                                                                      • 26 Bridge Circuits
                                                                                                                                                                                                                                                        • 261 Wheatstone Bridge
                                                                                                                                                                                                                                                        • 262 Constant-Current Bridge
                                                                                                                                                                                                                                                        • 263 Bridge Amplifiers
                                                                                                                                                                                                                                                          • 2631 Half-Bridge Circuits
                                                                                                                                                                                                                                                            • 264 Impedance Bridges
                                                                                                                                                                                                                                                              • 2641 Owen Bridge
                                                                                                                                                                                                                                                              • 2642 Wien-Bridge Oscillator
                                                                                                                                                                                                                                                                  • 27 Linearizing Devices
                                                                                                                                                                                                                                                                    • 271 Linearization by Software
                                                                                                                                                                                                                                                                    • 272 Linearization by Hardware Logic
                                                                                                                                                                                                                                                                    • 273 Analog Linearizing Circuitry
                                                                                                                                                                                                                                                                    • 274 Offsetting Circuitry
                                                                                                                                                                                                                                                                    • 275 Proportional-Output Circuitry
                                                                                                                                                                                                                                                                      • 2751 Curve-Shaping Circuitry
                                                                                                                                                                                                                                                                          • 28 Miscellaneous Signal Modification Circuitry
                                                                                                                                                                                                                                                                            • 281 Phase Shifters
                                                                                                                                                                                                                                                                            • 282 Voltage-to-Frequency Converter
                                                                                                                                                                                                                                                                            • 283 Frequency-to-Voltage Converter
                                                                                                                                                                                                                                                                            • 284 Voltage-to-Current Converters
                                                                                                                                                                                                                                                                            • 285 Peak-Hold Circuits
                                                                                                                                                                                                                                                                              • 29 Signal Analyzers and Display Devices
                                                                                                                                                                                                                                                                                • 291 Signal Analyzers
                                                                                                                                                                                                                                                                                • 292 Oscilloscopes
                                                                                                                                                                                                                                                                                  • 2921 Triggering
                                                                                                                                                                                                                                                                                  • 2922 Lissajous Patterns
                                                                                                                                                                                                                                                                                  • 2923 Digital Oscilloscopes
                                                                                                                                                                                                                                                                                      • Bibliography
                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                          • 53191ch3
                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                            • Chapter 3 Vibration Testing
                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                              • 31 Introduction
                                                                                                                                                                                                                                                                                              • 32 Representation of a Vibration Environment
                                                                                                                                                                                                                                                                                                • 321 Test Signals
                                                                                                                                                                                                                                                                                                  • 3211 Stochastic vs Deterministic Signals
                                                                                                                                                                                                                                                                                                    • 322 Deterministic Signal Representation
                                                                                                                                                                                                                                                                                                      • 3221 Single-Frequency Signals
                                                                                                                                                                                                                                                                                                      • 3222 Sine Sweep
                                                                                                                                                                                                                                                                                                      • 3223 Sine Dwell
                                                                                                                                                                                                                                                                                                      • 3224 Decaying Sine
                                                                                                                                                                                                                                                                                                      • 3225 Sine Beat
                                                                                                                                                                                                                                                                                                      • 3226 Sine Beat with Pauses
                                                                                                                                                                                                                                                                                                      • 3227 Multifrequency Signals
                                                                                                                                                                                                                                                                                                      • 3228 Actual Excitation Records
                                                                                                                                                                                                                                                                                                      • 3229 Simulated Excitation Signals
                                                                                                                                                                                                                                                                                                        • 323 Stochastic Signal Representation
                                                                                                                                                                                                                                                                                                          • 3231 Ergodic Random Signals
                                                                                                                                                                                                                                                                                                          • 3232 Stationary Random Signals
                                                                                                                                                                                                                                                                                                          • 3233 Independent and Uncorrelated Signals
                                                                                                                                                                                                                                                                                                          • 3234 Transmission of Random Excitations
                                                                                                                                                                                                                                                                                                            • 324 Frequency-Domain Representations
                                                                                                                                                                                                                                                                                                              • 3241 Fourier Spectrum Method
                                                                                                                                                                                                                                                                                                              • 3242 Power Spectral Density Method
                                                                                                                                                                                                                                                                                                                • 325 Response Spectrum
                                                                                                                                                                                                                                                                                                                  • 3251 Displacement Velocity and Acceleration Spectra
                                                                                                                                                                                                                                                                                                                  • 3252 Response-Spectra Plotting Paper
                                                                                                                                                                                                                                                                                                                  • 3253 Zero-Period Acceleration
                                                                                                                                                                                                                                                                                                                  • 3254 Uses of Response Spectra
                                                                                                                                                                                                                                                                                                                    • 326 Comparison of Various Representations
                                                                                                                                                                                                                                                                                                                      • 33 Pretest Procedures
                                                                                                                                                                                                                                                                                                                        • 331 Purpose of Testing
                                                                                                                                                                                                                                                                                                                        • 332 Service Functions
                                                                                                                                                                                                                                                                                                                          • 3321 Active Equipment
                                                                                                                                                                                                                                                                                                                          • 3322 Passive Equipment
                                                                                                                                                                                                                                                                                                                          • 3323 Functional Testing
                                                                                                                                                                                                                                                                                                                            • 333 Information Acquisition
                                                                                                                                                                                                                                                                                                                              • 3331 Interface Details
                                                                                                                                                                                                                                                                                                                              • 3332 Effect of Neglecting Interface Dynamics
                                                                                                                                                                                                                                                                                                                              • 3333 Effects of Damping
                                                                                                                                                                                                                                                                                                                              • 3334 Effects of Inertia
                                                                                                                                                                                                                                                                                                                              • 3335 Effect of Natural Frequency
                                                                                                                                                                                                                                                                                                                              • 3336 Effect of Excitation Frequency
                                                                                                                                                                                                                                                                                                                              • 3337 Other Effects of Interface
                                                                                                                                                                                                                                                                                                                                • 334 Test-Program Planning
                                                                                                                                                                                                                                                                                                                                  • 3341 Testing of Cabinet-Mounted Equipment
                                                                                                                                                                                                                                                                                                                                    • 335 Pretest Inspection
                                                                                                                                                                                                                                                                                                                                      • 34 Testing Procedures
                                                                                                                                                                                                                                                                                                                                        • 341 Resonance Search
                                                                                                                                                                                                                                                                                                                                        • 342 Methods of Determining Frequency-Response Functions
                                                                                                                                                                                                                                                                                                                                          • 3421 Fourier Transform Method
                                                                                                                                                                                                                                                                                                                                          • 3422 Spectral Density Method
                                                                                                                                                                                                                                                                                                                                          • 3423 Harmonic Excitation Method
                                                                                                                                                                                                                                                                                                                                            • 343 Resonance-Search Test Methods
                                                                                                                                                                                                                                                                                                                                              • 3431 Hammer (Bump) Test and Drop Test
                                                                                                                                                                                                                                                                                                                                              • 3432 Pluck Test
                                                                                                                                                                                                                                                                                                                                              • 3433 Shaker Tests
                                                                                                                                                                                                                                                                                                                                                • 344 Mechanical Aging
                                                                                                                                                                                                                                                                                                                                                  • 3441 Equivalence for Mechanical Aging
                                                                                                                                                                                                                                                                                                                                                  • 3442 Excitation-Intensity Equivalence
                                                                                                                                                                                                                                                                                                                                                  • 3443 Dynamic-Excitation Equivalence
                                                                                                                                                                                                                                                                                                                                                  • 3444 Cumulative Damage Theory
                                                                                                                                                                                                                                                                                                                                                    • 345 Test-Response Spectrum Generation
                                                                                                                                                                                                                                                                                                                                                    • 346 Instrument Calibration
                                                                                                                                                                                                                                                                                                                                                    • 347 Test-Object Mounting
                                                                                                                                                                                                                                                                                                                                                    • 348 Test-Input Considerations
                                                                                                                                                                                                                                                                                                                                                      • 3481 Test Nomenclature
                                                                                                                                                                                                                                                                                                                                                      • 3482 Testing with Uncorrelated Excitations
                                                                                                                                                                                                                                                                                                                                                      • 3483 Symmetrical Rectilinear Testing
                                                                                                                                                                                                                                                                                                                                                      • 3484 Geometry vs Dynamics
                                                                                                                                                                                                                                                                                                                                                      • 3485 Some Limitations
                                                                                                                                                                                                                                                                                                                                                      • 3486 Testing Black Boxes
                                                                                                                                                                                                                                                                                                                                                      • 3487 Phasing of Excitations
                                                                                                                                                                                                                                                                                                                                                      • 3488 Testing a Gray or White Box
                                                                                                                                                                                                                                                                                                                                                      • 3489 Overtesting in Multitest Sequences
                                                                                                                                                                                                                                                                                                                                                          • 35 Some Practical Information
                                                                                                                                                                                                                                                                                                                                                            • 351 Random Vibration Test Example
                                                                                                                                                                                                                                                                                                                                                            • 352 Vibration Shakers and Control Systems
                                                                                                                                                                                                                                                                                                                                                              • Bibliography
                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                  • 53191ch4
                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                    • Chapter 4 Experimental Modal Analysis
                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                      • 41 Introduction
                                                                                                                                                                                                                                                                                                                                                                      • 42 Frequency-Domain Formulation
                                                                                                                                                                                                                                                                                                                                                                        • 421 Transfer-Function Matrix
                                                                                                                                                                                                                                                                                                                                                                        • 422 Principle of Reciprocity
                                                                                                                                                                                                                                                                                                                                                                          • 43 Experimental Model Development
                                                                                                                                                                                                                                                                                                                                                                            • 431 Extraction of the Time-Domain Model
                                                                                                                                                                                                                                                                                                                                                                              • 44 Curve Fitting of Transfer Functions
                                                                                                                                                                                                                                                                                                                                                                                • 441 Problem Identification
                                                                                                                                                                                                                                                                                                                                                                                • 442 Single- and Multi-Degree-of-Freedom Techniques
                                                                                                                                                                                                                                                                                                                                                                                • 443 Single-Degree-of-Freedom Parameter Extraction in the Frequency Domain
                                                                                                                                                                                                                                                                                                                                                                                  • 4431 Circle-Fit Method
                                                                                                                                                                                                                                                                                                                                                                                    • Case of Viscous Damping
                                                                                                                                                                                                                                                                                                                                                                                    • Case of Hysteretic Damping
                                                                                                                                                                                                                                                                                                                                                                                      • 4432 Peak-Picking Method
                                                                                                                                                                                                                                                                                                                                                                                        • 444 Multi-Degree of Freedom Curve Fitting
                                                                                                                                                                                                                                                                                                                                                                                          • 4441 Formulation of the Method
                                                                                                                                                                                                                                                                                                                                                                                            • 445 A Comment on Static Modes and Rigid-Body Modes
                                                                                                                                                                                                                                                                                                                                                                                            • 446 Residue Extraction
                                                                                                                                                                                                                                                                                                                                                                                              • 45 Laboratory Experiments
                                                                                                                                                                                                                                                                                                                                                                                                • 451 Lumped-Parameter System
                                                                                                                                                                                                                                                                                                                                                                                                  • 4511 Frequency-Domain Test
                                                                                                                                                                                                                                                                                                                                                                                                  • 4512 Time-Domain Tests
                                                                                                                                                                                                                                                                                                                                                                                                    • 452 Distributed-Parameter System
                                                                                                                                                                                                                                                                                                                                                                                                      • 46 Commercial EMA Systems
                                                                                                                                                                                                                                                                                                                                                                                                        • 461 System Configuration
                                                                                                                                                                                                                                                                                                                                                                                                          • 4611 FFT Analysis Options
                                                                                                                                                                                                                                                                                                                                                                                                          • 4612 Modal Analysis Components
                                                                                                                                                                                                                                                                                                                                                                                                              • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                  • 53191ch5
                                                                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                    • Chapter 5 Mechanical Shock
                                                                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                      • 51 Definitions
                                                                                                                                                                                                                                                                                                                                                                                                                        • 511 Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 512 Simple (or Perfect) Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 513 Half-Sine Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 514 Versed-Sine (or Haversine) Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 515 Terminal Peak Sawtooth Shock or Final Peak Sawtooth Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 516 Rectangular Shock
                                                                                                                                                                                                                                                                                                                                                                                                                          • 5161 Trapezoidal Shock
                                                                                                                                                                                                                                                                                                                                                                                                                              • 52 Description in the Time Domain
                                                                                                                                                                                                                                                                                                                                                                                                                              • 53 Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                • 531 Need
                                                                                                                                                                                                                                                                                                                                                                                                                                • 532 Shock Response Spectrum Definition
                                                                                                                                                                                                                                                                                                                                                                                                                                • 533 Response of a Linear One-Degree-of-Freedom System
                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5331 Shock Defined by a Force
                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5332 Shock Defined by an Acceleration
                                                                                                                                                                                                                                                                                                                                                                                                                                    • 534 Definitions
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5341 Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5342 Absolute Acceleration Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5343 Relative Displacement Shock Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5344 Primary Positive Shock Response Spectrum or Initial Positive Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5345 Primary (or Initial) Negative Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5346 Secondary (or Residual) Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5347 Positive (or Maximum Positive) Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5348 Negative (or Maximum Negative) Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5349 Maximax Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53410 Choice of Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                        • 535 Standardized Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5351 Definition
                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5352 Standardized Shock Response Spectra of Simple Shocks
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53521 Half-Sine Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53522 Versed Sine Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53523 Terminal Peak Sawtooth Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53524 Rectangular Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53525 Trapezoidal Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 536 Choice of Damping
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 537 Shock Response Spectra Domains
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 538 Algorithms for Calculation of the Shock Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 539 Choice of the Digitization Frequency of the Signal
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5310 Use of Shock Response Spectra for the Study of Systems with Several Degrees of Freedom
                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 54 Pyroshocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 55 Use of Shock Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 551 Severity Comparison of Several Shocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 552 Test Specification Development from Real Environment Data
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5521 Synthesis of Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5522 Nature of the Specification
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5523 Choice of Shape
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5524 Amplitude
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5525 Duration
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5526 Difficulties
                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 56 Standards
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 561 Types of Standards
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 562 Installation Conditions of Test Item
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 563 Uncertainty Factor
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 564 Bump Test
                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 57 Damage Boundary Curve
                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 571 Definition
                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 572 Analysis of Test Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 58 Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 581 Main Types
                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 582 Impact Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5821 Universal Shock-Test Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 58211 Impact Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 58212 Impulse Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 583 Shock Simulators (Programmers)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5831 Half-Sine Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58311 Shock Duration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58312 Impact Velocity
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58313 Maximum Deformation of the Shock Simulator (Programmer)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58314 Shock Amplitude
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58315 Characteristics of the Target
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5832 Terminal Peak Sawtooth Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5833 Rectangular Pulse ndash Trapezoidal Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5834 Universal Shock Simulator (Programmer)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 58341 Generating a Half-Sine Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 58342 Generating a Terminal Peak Sawtooth Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 58343 Trapezoidal Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 584 Limitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5841 Limitations of the Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5842 Limitations of Shock Simulators
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 585 Pneumatic Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 586 High Impact Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5861 Lightweight High Impact Shock Machine
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5862 Medium Weight High Impact Shock Machine
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 587 Specific Test Facilities
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 59 Generation of Shock Using Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 591 Principle Behind the Generation of a Simple Shape Signal versus Time
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 592 Main Advantages
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 593 Pre- and Postshocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5931 Requirements
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5932 Solutions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 59321 Optimized Pre- and Postpulses
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5933 Incidence on the Shock Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 594 Limitations of Electrodynamic Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5941 Mechanical Limitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 59411 Abacuses
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5942 Electronic Limitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 595 The Use of Electrohydraulic Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 510 Control by a Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 5101 Principle
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 5102 Principal Shapes of Elementary Signals
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 51021 Decaying Sinusoid
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 51022 ZERD Function
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 51023 WAVSIN Waveform
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 5103 Comparison of WAVSIN SHOC Waveforms and Decaying Sinusoid
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 5104 Criticism of Control by a Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 511 Pyrotechnic Shock Simulation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5111 Simulation Using Pyrotechnic Facilities
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5112 Simulation Using Metal-to-Metal Impact
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5113 Simulation Using Electrodynamic Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5114 Simulation Using Conventional Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53191ch6
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Chapter 6 Machine Condition Monitoring and Fault Diagnostics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 61 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 62 Machinery Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 621 Causes of Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 622 Types of Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 623 Frequency of Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 63 Basic Maintenance Strategies
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 631 Run-to-Failure (Breakdown) Maintenance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 632 Scheduled (Preventative) Maintenance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 633 Condition-Based (Predictive Proactive Reliability Centered On-Condition) Maintenance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 64 Factors Which Influence Maintenance Strategy
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 65 Machine Condition Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 651 Periodic Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 652 Continuous Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 66 Transducer Selection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 661 Noncontact Displacement Transducers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 662 Velocity Transducers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 663 Acceleration Transducers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 67 Transducer Location
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 68 Recording and Analysis Instrumentation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 681 Vibration Meters
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 682 Data Collectors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 683 Frequency-Domain Analyzers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 684 Time-Domain Instruments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 685 Tracking Analyzers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 69 Display Formats and Analysis Tools
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 691 Time Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6911 Time-Waveform Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6912 Time-Waveform Indices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6913 Time-Synchronous Averaging
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6914 Negative Averaging
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6915 Orbits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6916 Probability Density Functions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6917 Probability Density Moments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 692 Frequency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6921 Band-Pass Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6922 Shock Pulse (Spike Energy)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6923 Enveloped Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6924 Signature Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6925 Cascades (Waterfall Plots)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6926 Masks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6927 Frequency-Domain Indices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 693 Modal Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 694 Quefrency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 610 Fault Detection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 6101 Standards
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61011 Standards Based on Machinery Type
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61012 Standards Based on Vibration Severity
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 6102 Acceptance Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 61021 Statistical Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 6103 Frequency-Domain Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61031 Limited Band Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61032 Constant Bandwidth Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61033 Constant Percentage Bandwidth Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 611 Fault Diagnostics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 6111 Forcing Functions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61111 Unbalance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61112 Misalignment
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61113 Mechanical Looseness
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61114 Soft Foot
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61115 Rubs
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61116 Resonances
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61117 Oil Whirl
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61118 Oil Whip
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61119 Structural Vibrations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 611110 Foundation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 6112 Specific Machine Components
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 61121 Damaged or Worn Rolling-Element Bearings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 61122 Damaged or Worn Gears
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 6113 Specific Machine Types
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61131 Pumps
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61132 Fans
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61133 Electric Motors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61134 Steam and Gas Turbines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61135 Compressors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61136 Reciprocating Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 6114 Advanced Fault Diagnostic Techniques
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 53191ch7
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • Chapter 7 Vibration-Based Tool Condition Monitoring Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 71 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 72 Mechanics of Turning
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 721 General Terms
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 722 Chatter Vibrations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 723 Tool Wear
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7231 Tool Failure Mechanisms
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7232 Tool Failure Modes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7233 Tool Wear Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7234 Tool Wear Stages
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 73 Vibration Signal Recording
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 731 Direct and Indirect Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 732 Sensor Requirements for Tool Wear Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 733 Force Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7331 Direct Measurement Dynamometers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7332 Indirect Force Sensors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7333 Piezoelectric Strain Sensors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7334 Resistance Strain Gauges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7335 Customized Force Sensors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 734 Acceleration Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 735 Acoustic Emission Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 736 Sensor Comparisons
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 74 Signal Processing for Sensor-Based Tool Condition Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 741 Feature Extraction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7411 Time Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7412 Frequency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7413 Statistical Processing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7414 TimendashFrequency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 742 Feature Selection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 75 Wear ModelDecision-Making for Sensor-Based Tool Condition Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 751 Trending Threshold
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 752 Neural Networks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7521 Unsupervised Networks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7522 Supervised Networks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 753 Fuzzy Logic
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 754 Other Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 76 Conclusion
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53191ch8
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Chapter 8 Fault Diagnosis of Helicopter Gearboxes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 81 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 82 Abnormality Scaling
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 83 The Structure-Based Connectionist Network
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 84 Sensor Location Selection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 841 Coverage Index
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 842 Overlap Index
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 843 Monitoring Effectiveness
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 85 A Case Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 851 Structural and Featural Influences
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 852 Evaluation of Influences
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 853 Fault Detection Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 854 Fault Diagnostic Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 8541 Faulty Subsystem Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 8542 Faulty Component Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 855 Sensor Location Evaluation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 856 Sensor Location Validation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 86 Conclusion
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 53191ch9
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Chapter 9 Vibration Suppression and Monitoring in Precision Motion Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 91 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 92 Mechanical Design to Minimize Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 921 Stability and Static Determinacy of Machine Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 922 Two-Dimensional Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 923 Three-Dimensional Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 93 Adaptive Notch Filter
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 931 Fast Fourier Transform
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 932 Simulation and Experiments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 94 Real-Time Vibration Analyzer
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 941 Learning Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 942 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 943 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 944 Experiments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 9441 Input Variables mdash the Evaluation Criteria
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 94411 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 94412 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 9442 Evaluation Rules
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 94421 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 94422 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 9443 Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 94431 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 94432 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 95 Practical Insights and Case Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 96 Conclusions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 53191ch10
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Chapter 10 Vibration and Shock Problems of Civil Engineering Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 101 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 102 Earthquake-Induced Vibration of Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1021 Seismicity and Ground Motions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1022 Influence of Local Site Conditions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1023 Response of Structures to Ground Motions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1024 Dynamic Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10241 Equations of Motion for Linear Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10242 Equations of Motion for Linear Multiple-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1025 Earthquake Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10251 Elastic Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10252 Smoothed Design Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10253 Ductility-Modified Response Spectrum Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1026 Design Philosophy and the Code Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10261 Performance-Based Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1027 Analysis Options for Earthquake Effects
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10271 Dynamic Time History Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10272 Response Spectrum Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 102721 Response Spectrum Analysis of Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 102722 Response Spectrum Analysis of Multi-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10273 Equivalent Static Analysis (Force-Based Approach)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10274 Displacement-Based Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1028 SoilndashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1029 Active and Passive Control Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 10210 Worked Examples
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 103 Dynamic Effects of Wind Loading on Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1031 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1032 Wind Speed
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1033 Design Structures for Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10331 Types of Wind Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10332 Design Criteria
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10333 Static Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1034 Along and Across-Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10341 Along-Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10342 Across-Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1035 Wind Tunnel Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1036 Comfort Criteria Human Response to Building Motion
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1037 Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1038 Comparison with Earthquake Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 104 Vibrations Due to Fluid ndashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1041 Added Mass and Inertial Coupling
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1042 Wave-Induced Vibration of Structure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 105 Blast Loading and Blast Effects on Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1051 Explosions and Blast Phenomenon
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1052 Explosive Air-Blast Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10521 Blast Wave Scaling Laws
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10522 Prediction of Blast Pressure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1053 Gas Explosion Loading and Effect of Internal Explosions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1054 Structural Response to Blast Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10541 Elastic Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10542 Elasto-Plastic Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1055 Material Behaviors at High Strain Rate
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10551 Dynamic Properties of Concrete under High Strain Rates
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10552 Dynamic Properties of Reinforcing Steel under High Strain Rates
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1056 Failure Modes of Blast-Loaded Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10561 Global Structural Behavior
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10562 Localized Structural Behavior
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10563 PressurendashImpulse ( PndashI ) Diagrams
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1057 Blast WavendashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1058 Effect of Ground Shocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10581 Loads from Air-Induced Ground Shock
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10582 Loads from Direct Ground Shock
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1059 Technical Design Manuals for Blast-Resistant Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 10510 Computer Programs for Blast and Shock Effects
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 106 Impact Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1061 Structural Impact between Two Bodies mdash Hard Impact and Soft Impact
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1062 Example mdash Aircraft Impact
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 107 Floor Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1071 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1072 Types of Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10721 Walking
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10722 Rhythmic Activities
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10723 Mechanical Equipment
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10724 Analysis Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1073 Natural Frequency of Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10731 Computing the Natural Frequency
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10732 Computing Deflection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10733 Damping
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10734 Resonance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1074 Vibration Caused by Walking
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10741 Minimum Natural Frequency
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1075 Design for Rhythmic Excitation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10751 Harmonics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10752 Minimum Natural Frequency
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1076 Example mdash Vibration Analysis of a Reinforced Concrete Floor
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 53191ch11
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Chapter 11 Seismic Base Isolation and Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 111 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1111 From Ductility Design to Base Isolation and Control Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1112 The Importance of Reducing Seismic Input and Response
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 112 Seismic Base Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1121 Historical Development of Base Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1122 Basic Principle
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1123 Issues in Seismic Base Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11231 Performance Criteria
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11232 Type of Structure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11233 Site Characteristics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11234 Retrofit Issues
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11235 Design of Building Services
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11236 Expected Life of Isolator
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1124 Seismic Isolation Devices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11241 Laminated Rubber Bearings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11242 Lead Rubber Bearing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11243 Friction-Based Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11244 Other Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1125 Design of Isolation Devices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11251 High-Damping Rubber Bearing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112511 Stability against Buckling
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112512 Stability against Roll Out
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11252 Lead Rubber Bearings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112521 Design of Lead Plug
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112522 Design of Laminated Rubber Bearing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11253 Design of Friction Pendulum System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1126 Verification of Properties of Isolation Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11261 Tests for Isolation Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 112611 System Characterization Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 112612 Prototype Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 112613 Quality Control Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11262 Uniform Building Code Recommendations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112621 Units Dependent on Loading Rates
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112622 Units Dependent on Bilateral Load
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112623 System Adequacy
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1127 Analysis of Base-Isolated Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11271 Modeling of a Superstructure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11272 Modeling of Isolation System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11273 Static Analysis Procedure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11274 Dynamic Analysis Procedure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 112741 Response Spectrum Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 112742 Time-History Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11275 Software for Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1128 Experimental Methods for Isolated Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1129 Implementation of Seismic Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11291 New Construction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112911 Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112912 Bridges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11292 Seismic Retrofit
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112921 Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112922 Bridges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11293 Other Implementations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 11210 Performance during Past Earthquakes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 112101 Performance of Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 112102 Performance of Bridges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 113 Seismic Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1131 Historical Development of Seismic Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1132 Basic Principles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11321 Passive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11322 Active Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11323 Semiactive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11324 Hybrid Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11325 Categorization of Basic Principles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1133 Important Issues in Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11331 SoilndashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11332 DevicendashStructure Interaction and Time Delay
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11333 Design Guidelines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1134 Vibration-Control Devices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11341 Passive Control Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113411 Metallic Yielding Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113412 Friction Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113413 Viscoelastic Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113414 Viscous Fluid Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113415 Tuned Mass Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11342 Active Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113421 Electromagnetic Actuator
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113422 Hydraulic Actuators
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11343 Semiactive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113431 Variable-Orifice Hydraulic Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113432 Controllable Fluid Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113433 Controllable Friction Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11344 Hybrid Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1135 Control Algorithm
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11351 Active Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11352 Semiactive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113521 Common Control Schemes for Controllable Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113522 Special Control Schemes for Controllable Damper
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1136 Experimental Performance Verification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11361 Shaking Table Tests of a Flexible Structural Model with TMD AMD and ATMD
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11362 Substructure Hybrid Test
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113621 Hybrid Tests Using Hydraulic Actuator
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113622 Hybrid Tests Using Shaking Table
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113623 Hybrid Tests Using Inertia-Force-Driven Loading System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1137 Implementations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11371 Semiactive Control of Full-Scale Structures Using Variable Joint Damper System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113711 Background of Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113712 Test System Set Up
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113713 Control Algorithm
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113714 Test Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11372 Application of Structural Control Technologies to Seismic Retrofit of a Cable-Stayed Bridge
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113721 Background of Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113722 Basic Concept of Seismic Retrofit
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113723 Modal Shape Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113724 Time-History Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113725 Soil ndash Structure Interaction Effect
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113726 Semiactive Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53191ch12
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Chapter 12 Seismic Random Vibration of Long-Span Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 121 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1211 Basic Concepts of Random Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12111 Stationary Random Process
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12112 Nonstationary Random Process
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1212 Three Methods for Structural Seismic Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12121 Response Spectrum Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12122 Time-History Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12123 Random Vibration Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 121231 Davenport Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 121232 Vanmarcke Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 12124 Comparisons of the Three Seismic-Analysis Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 122 Seismic Random-Excitation Fields
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1221 Power Spectral Density of Spatially Varying Ground Acceleration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1222 Several Coherence Models
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12221 FengndashHu Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12222 Harichandran ndashVanmarcke Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12223 LohndashYeh Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12224 OliveirandashHaondashPenzien Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12225 LucondashWong Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12226 QundashWangndashWang Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1223 Generation of Ground Acceleration Power Spectral Density Curves from Acceleration Response Spectrum Curves
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12231 Kaul Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12232 Iteration Scheme
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1224 Seismic Equations of Motion of Long-Span Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1225 Seismic Waves and Their Geometrical Expressions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 123 Pseudoexcitation Method for Structural Random Vibration Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1231 Structures Subjected to Stationary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12311 Single Stationary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12312 Multiple Stationary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1232 Structures Subjected to Nonstationary Random Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12321 Structures Subjected to Uniformly Modulated Evolutionary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 123211 Single Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 123212 Multiple Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12322 Structures Subjected to Nonuniformly Modulated Evolutionary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 123221 Single Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 123222 Multiple Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1233 Precise Integration Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12331 Precise Integration of Exponential Matrices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12332 Particular Solutions and Precise Integration Formulas for Various Forms of Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 123321 Linear Loading Form (HPD-L Form)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 123322 Sinusoidal Loading Form (HPD-S Form)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 123323 Exponentially Decaying Sinusoidal Loading Form (HPD-E Form)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 124 Long-Span Structures Subjected to Stationary Random Ground Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1241 The Solution of Equations of Motion Using the Pseudoexcitation Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1242 Numerical Comparisons with Other Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12421 Song-Hua-Jiang Suspension Bridge
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 124211 All Supports Move Uniformly
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 124212 Wave Passage Effect Is Taken into Account
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 124213 Wave-Passage Effect and Incoherence Effect Are Jointly Taken into Account
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 12422 San Joaquin Concrete Bridge
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 125 Long-Span Structures Subjected to Nonstationary Random Ground Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1251 Modulation Functions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1252 The Formulas for Nonstationary Multiexcitation Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1253 Expected Extreme Values of Nonstationary Random Processes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1254 Numerical Comparisons with the Corresponding Stationary Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 126 Conclusions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 53191ch13
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Chapter 13 Seismic Qualification of Equipment
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 131 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 132 Distribution Qualification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1321 Drive-Signal Generation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1322 Distribution Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1323 Test Procedures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 133 Seismic Qualification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1331 Stages of Seismic Qualification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1332 Test Preliminaries
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1333 Single-Frequency Testing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1334 Multifrequency Testing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1335 Generation of RRS Specifications
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 53191ch14
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                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Chapter 14 Human Response to Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 141 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 142 Vibration Excitations on Humans
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1421 Excitation Characteristics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 143 Human Response to Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1431 Vibration Perception
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1432 Frequency Weighting Curve
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1433 Iso-Perception Curves
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1434 Detection Threshold Curve
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 144 Regulation of Human Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1441 Acceptable Vibration Levels in Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1442 Whole-Body Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1443 HandndashArm Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
Page 18: Vibration Monitoring, Testing, and Instrumentationpreview.kingborn.net › 646000 › d1a74678d91943e5ba1d5e... · The MEMS Handbook, Second Edition MEMS: Introduction and Fundamentals

An idealized performance curve of a shaker

has a constant displacementndashamplitude region a

constant velocityndashamplitude region and a con-

stant accelerationndashamplitude region for low

intermediate and high frequencies respectively

in the operating frequency range Such an ideal

performance curve is shown in Figure 13(a) on a

frequencyndashvelocity plane Logarithmic axes are

used In practice typical shaker performance

curves would be fairly smooth yet nonlinear

curves similar to those shown in Figure 13(b)

As the mass increases the performance curve

compresses Note that the acceleration limit of a

shaker depends on the mass of the test object

(load) Full load corresponds to the heaviest object

that could be tested The ldquono loadrdquo condition

corresponds to a shaker without a test object To

standardize the performance curves they are

usually defined at the rated load of the shaker A

performance curve in the frequencyndashvelocity

plane may be converted to a curve in the

frequencyndashacceleration plane simply by increasing

the slope of the curve by a unit magnitude (ie

20 dbdecade)

Several general observations can be made from

Equation 14 and Equation 15 In the constant-

peak displacement region of the performance

curve the peak velocity increases proportionally

with the excitation frequency and the peak

acceleration increases with the square of the excitation frequency In the constant-peak velocity region

the peak displacement varies inversely with the excitation frequency and the peak acceleration increases

proportionately In the constant-peak acceleration region the peak displacement varies inversely with the

square of the excitation frequency and the peak velocity varies inversely with the excitation frequency

This further explains why rated stroke maximum velocity and maximum acceleration values are not

simultaneously realized

121 Shaker Selection

Vibration testing is accomplished by applying a specified excitation to the test package using a shaker

apparatus and monitoring the response of the test object Test excitation may be represented by its

response spectrum The test requires that the response spectrum of the actual excitation known as the

test response spectrum (TRS) envelops the response spectrum specified for the particular test known as

the required response spectrum (RRS)

A major step in the planning of any vibration testing program is the selection of a proper shaker

(exciter) system for a given test package The three specifications that are of primary importance in

selecting a shaker are the force rating the power rating and the stroke (maximum displacement) rating

Force and power ratings are particularly useful in moderate to high frequency excitations and the stroke

rating is the determining factor for low frequency excitations In this section a procedure is given to

determine conservative estimates for these parameters in a specified test for a given test package

Frequency domain considerations are used here

Stroke

Limit M

ax

Acceleration

MaxVelocity

Peak

Vel

ocity

(cm

s)

01 1 10 100

FullLoad

NoLoad

Frequency (Hz)(a)

Peak

Vel

ocity

(cm

s)

100

10

1

100

10

1

01 1 10 100

FullLoad

NoLoad

Frequency (Hz)(b)

FIGURE 13 Performance curve of a vibration exciter

in the frequencyndashvelocity plane (log) (a) ideal (b)

typical

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copy 2007 by Taylor amp Francis Group LLC

1211 Force Rating

In the frequency domain the (complex) force at the exciter (shaker) head is given by

F frac14 mHethvTHORNasethvTHORN eth16THORNin which v is the excitation frequency variable m is the total mass of the test package including

mounting fixture and attachments asethvTHORN is the Fourier spectrum of the support-location (exciter head)

acceleration and H(v) is frequency response function that takes into account the flexibility and

damping effects (dynamics) of the test package apart from its inertia In the simplified case where the

test package can be represented by a simple oscillator of natural frequency vn and damping ratio by zt

this function becomes

HethvTHORN frac14 1thorn 2jztv=vn=12 ethv=vnTHORN2 thorn 2jztv=vn eth17THORNin which j frac14 ffiffiffiffi

21p

This approximation is adequate for most practical purposes The static weight of the

test object is not included in Equation 16 Most heavy-duty shakers which are typically hydraulic

have static load support systems such as pneumatic cushion arrangements that can exactly balance the

dead load The exciter provides only the dynamic force In cases where shaker directly supports the

gravity load in the vertical test configuration Equation 16 should be modified by adding a term to

represent this weight

A common practice in vibration test applications is to specify the excitation signal by its response

spectrum This is simply the peak response of a simple oscillator expressed as a function of its natural

frequency when its support location is excited by the specified signal Clearly the damping of the simple

oscillator is an added parameter in a response spectrum specification Typical damping ratios ethzrTHORN used inresponse spectra specifications are less than 01 (or 10) It follows that an approximate relationship

between the Fourier spectrum of the support acceleration and its response spectrum is

as frac14 2jzrarethvTHORN eth18THORNThe magnitude larethvTHORNl is the response spectrumEquation 18 substituted into Equation 16 gives

F frac14 mHethvTHORN2jzrarethvTHORN eth19THORNIn view of Equation 17 for test packages having low damping the peak value of H(v) is

approximately 1=eth2jztTHORN this should be used in computing the force rating if the test package has a

resonance within the frequency range of testing On the other hand if the test package is assumed to be

rigid then HethvTHORN oslash 1 A conservative estimate for the force rating is

Fmax frac14 methzr=ztTHORNlarethvTHORNlmax eth110THORNIt should be noted that larethvTHORNlmax is the peak value of the specified (required) response spectrum (RRS)

for acceleration

1212 Power Rating

The exciter head does not develop its maximum force when driven at maximum velocity Output power

is determined by using

p frac14 Refrac12FvsethvTHORN eth111THORNin which vsethvTHORN is the Fourier spectrum of the exciter velocity and Re [ ] denotes the real part of a complex

function Note that as frac14 jvvs Substituting Equation 16 and Equation 18 into Equation 111 gives

p frac14 eth4mz2r =vTHORNRefrac12jHethvTHORNa2r ethvTHORN eth112THORNIt follows that a conservative estimate for the power rating is

pmax frac14 2methz2r =ztTHORNfrac12larethvTHORNl2=v max eth113THORN

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Representative segments of typical acceleration RRS curves have slope n as given by

a frac14 k1vn eth114THORN

It should be clear from Equation 113 that the maximum output power is given by

pmax frac14 k2v2n21 eth115THORN

This is an increasing function for n 1=2 and a decreasing function for n 1=2 It follows that the power

rating corresponds to the highest point of contact between the acceleration RRS curve and a line of slope

equal to 12 A similar relationship may be derived if velocity RRS curves (having slopes n2 1) are used

1213 Stroke Rating

From Equation 18 it should be clear that the Fourier spectrum xs of the exciter displacement time

history can be expressed as

xs frac14 2zrarethvTHORN=jv2 eth116THORNAn estimate for stroke rating is

xmax frac14 2zrfrac12larethvTHORNl=v2 max eth117THORNThis is of the form

xmax frac14 kvn22 eth118THORNIt follows that the stroke rating corresponds to the highest point of contact between the acceleration

RRS curve and a line of slope equal to two

Example 11

A test package of overall mass 100 kg is to be

subjected to dynamic excitation represented by the

acceleration RRS (at 5 damping) as shown in

Figure 14 The estimated damping of the test

package is 7 The test package is known to have a

resonance within the frequency range of the

specified test Determine the exciter specifications

for the test

Solution

From the development presented in the previous

section it is clear that the point F (or P) in

Figure 14 corresponds to the force and output

power ratings and the point S corresponds to

the stroke rating The co-ordinates of these

critical points are F P frac14 eth42 Hz 40 gTHORN and S frac14 eth08 Hz 075 gTHORN Equation 110 gives the force

rating as

Fmax frac14 100 pound eth005=007THORN pound 40 pound 981 N frac14 2803 N

Equation 113 gives the power rating as

pmax frac14 2 pound 100 pound eth0052=007THORN pound frac12eth40 pound 981THORN2=42 pound 2p watts frac14 417 W

Equation 117 gives the stroke rating as

xmax frac14 2 pound 005 pound frac12eth075 pound 98THORN=eth08 pound 2pTHORN2 m frac14 3 cm

Acc

eler

atio

n(g

)

Con

stan

t Dis

plac

emen

t

Constant Velo

city

Frequency (Hz)

S

FP

0101

10 10 100

10

10

FIGURE 14 Test excitation specified by an accelera-

tion RRS (5 damping)

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1214 Hydraulic Shakers

A typical hydraulic shaker consists of a piston-cylinder arrangement (also called a ram) a servo-valve a

fluid pump and a driving electric motor Hydraulic fluid (oil) is pressurized (typical operating pressure

4000 psi) and pumped into the cylinder through a servo-valve by means of a pump that is driven by an

electric motor (typical power 150 hp) The flow (typical rate 100 galmin) that enters the cylinder is

controlled (modulated) by the servo-valve which in effect controls the resulting piston (ram) motion

A typical servo-valve consists of a two-stage spool valve which provides a pressure difference and a

controlled (modulated) flow to the piston which sets it in motion

The servo-valve itself is moved by means of a linear torque motor which is driven by the excitation-

input signal (electrical) A primary function of the servo-valve is to provide a stabilizing feedback to the

ram In this respect the servo-valve complements the main control system of the test setup The ram is

coupled to the shaker table by means of a link with some flexibility The cylinder frame is mounted on the

support foundation with swivel joints This allows for some angular and lateral misalignment which

might be caused primarily by test-object dynamics as the table moves

Two-degree-of-freedom (Two-DoF) testing requires two independent sets of actuators and three-DoF

testing requires three independent actuator sets Each independent actuator set can consist of several

actuators operated in parallel using the same pump and the same excitation-input signal to the torque

motors

If the test table is directly supported on the vertical actuators they must withstand the total dead

weight (ie the weight of the test table the test object the mounting fixtures and the instrumentation)

This is requirement is usually prevented by providing a pressurized air cushion in the gap between the

test table and the foundation walls Air should be pressurized so as to balance the total dead weight

exactly (typical required gage pressure 3 psi)

Figure 15(a) shows the basic components of a typical hydraulic shaker The corresponding

operational block diagram is shown in Figure 15(b) It is desirable to locate the actuators in a pit in the

test laboratory so that the test tabletop is flushed with the test laboratory floor under no-load conditions

This minimizes the effort required to place the test object on the test table Otherwise the test object has

to be lifted onto the test table with a forklift Also installation of an aircushion to support the system

dead weight is difficult under these circumstances of elevated mounting

Hydraulic actuators are most suitable for heavy load testing and are widely used in industrial and civil

engineering applications They canbeoperated at very low frequencies (almost direct current [DC]) aswell

as at intermediate frequencies (see Table 11) Large displacements (stroke) are possible at low frequencies

Hydraulic shakers have the advantage of providing high flexibility of operation during the test their

capabilities include variable-force and constant-force testing and wide-band random-input testing The

velocity and acceleration capabilities of hydraulic shakers are moderate Although any general excitation-

input motion (for example sine wave sine beat wide-band random) can be used in hydraulic shakers

faithful reproduction of these signals is virtually impossible at high frequencies because of distortion and

higher-order harmonics introduced by the high noise levels that are common in hydraulic systems This

is only a minor drawback in heavy-duty intermediate-frequency applications Dynamic interactions are

reduced through feedback control

1215 Inertial Shakers

In inertial shakers or ldquomechanical excitersrdquo the force that causes the shaker-table motion is generated by

inertia forces (accelerating masses) Counter-rotating-mass inertial shakers are typical in this category

To understand their principle of operation consider two equal masses rotating in opposite directions at

the same angular speed v and in the same circle of radius r (see Figure 16) This produces a resultant

force equal to 2mv2r cos vt in a fixed direction (the direction of symmetry of the two rotating arms)

Consequently a sinusoidal force with a frequency of v and an amplitude proportional to v2 is generated

This reaction force is applied to the shaker table

Figure 17 shows a sketch of a typical counter-rotating-mass inertial shaker It consists of two identical

rods rotating at the same speed in opposite directions Each rod has a series of slots in which to

Vibration Instrumentation 1-9

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place weights In this manner the magnitude of

the eccentric mass can be varied to achieve various

force capabilities The rods are driven by a

variable-speed electric motor through a gear

mechanism that usually provides several speed

ratios A speed ratio is selected depending on the

required test-frequency range The whole system is

symmetrically supported on a carriage that is

directly connected to the test table The test object

is mounted on the test table The preferred

mounting configuration is horizontal so that the

excitation force is applied to the test object in a

horizontal direction In this configuration there

are no variable gravity moments (weight pounddistance to center of gravity) acting on the drive

mechanism Figure 17 shows the vertical con-

figuration In dynamic testing of large structures

the carriage can be mounted directly on the

structure at a location where the excitation force

should be applied By incorporating two pairs of

counter-rotating masses it is possible to generate

test moments as well as test forces

FIGURE 15 A typical hydraulic shaker arrangement (a) schematic diagram (b) operational block diagram

m m

2mw2r cos wt

wtw w

wt

FIGURE 16 Principle of operation of a counter-

rotating-mass inertial shaker

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copy 2007 by Taylor amp Francis Group LLC

Reaction-type shakers driven by inertia are widely used for the prototype testing of civil engineering

structures Their first application dates back to 1935 Inertial shakers are capable of producing

intermediate excitation forces The force generated is limited by the strength of the carriage frame The

frequency range of operation and the maximum velocity and acceleration capabilities are also

intermediate for inertial shakers whereas the maximum displacement capability is typically low A major

limitation of inertial shakers is that their excitation force is exclusively sinusoidal and that the force

amplitude is directly proportional to the square of the excitation frequency As a result complex and

random excitation testing constant-force testing (for example transmissibility tests and constant-force

sine-sweep tests) and flexibility to vary the force amplitude or the displacement amplitude during a test

are not generally feasible with this type of shakers Excitation frequency and amplitude can be varied

during testing however by incorporating a variable-speed drive for the motor The sinusoidal excitation

generated by inertial shakers is virtually undistorted which gives them an advantage over the other types

of shakers when used in sine-dwell and sine-sweep tests Small portable shakers with low-force capability

are available for use in on-site testing

1216 Electromagnetic Shakers

In electromagnetic shakers or ldquoelectrodynamic excitersrdquo the motion is generated using the principle of

operation of an electric motor Specifically the excitation force is produced when a variable excitation

signal (electrical) is passed through a moving coil placed in a magnetic field

The components of a commercial electromagnetic shaker are shown in Figure 18 A steady magnetic

field is generated by a stationary electromagnet that consists of field coils wound on a ferromagnetic base

that is rigidly attached to a protective shell structure The shaker head has a coil wound around it When

the excitation electrical signal is passed through this drive coil the shaker head which is supported on

flexure mounts will be set in motion The shaker head consists of the test table on which the test object

is mounted Shakers with interchangeable heads are available The choice of appropriate shaker head is

based on the geometry and mounting features of the test object The shaker head can be turned to

different angles by means of a swivel joint In this manner different directions of excitation (in biaxial

and triaxial testing) can be obtained

FIGURE 17 Sketch of a counter-rotating-mass inertial shaker

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122 Dynamics of Electromagnetic Shakers

Consider a single axis electromagnetic shaker (Figure 18) with a test object having a single natural

frequency of importance within the test frequency range The dynamic interactions between the shaker

and the test object give rise to two significant natural frequencies (and correspondingly two significant

resonances) These appear as peaks in the frequency response curve of the test setup Furthermore the

natural frequency (resonance) of the test package alone causes a ldquotroughrdquo or depression (antiresonance)

in the frequency response curve of the overall test setup To explain this characteristic consider the

dynamic model shown in Figure 19 The following mechanical parameters are defined for

Figure 19(a) m k and b are the mass stiffness and equivalent viscous damping constant respectively

of the test package and me ke and be are the corresponding parameters of the exciter (shaker) Also in

the equivalent electrical circuit of the shaker head as shown in Figure 19(b) the following electrical

parameters are defined Re and Le are the resistance and (leakage) inductance and kb is the back

electromotive force (back emf) of the linear motor Assuming that the gravitational forces are supported

FIGURE 18 Schematic sectional view of a typical electromagnetic shaker manufactured by Bruel and Kjaer

Denmark

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copy 2007 by Taylor amp Francis Group LLC

by the static deflections of the flexible elements and that the displacements are measured from the static

equilibrium position we have the following system equations

Test object meuroy frac14 2kethy2 yeTHORN2 beth_y2 _yeTHORN eth119THORNShaker head me euroye frac14 fe thorn kethy2 yeTHORN thorn beth_y2 _yeTHORN2 key 2 be _ye eth120THORN

Electrical Lediedt

thorn Reie thorn kb _ye frac14 vethtTHORN eth121THORN

The electromagnetic force fe generated in the shaker head is a result of the interaction of the magnetic

field generated by the current ie with coil of the moving shaker head and the constant magnetic field

(stator) in which the head coil is located Here we have

fe frac14 kbie eth122THORNNote that v(t) is the voltage signal that is applied by the amplifier to the shaker coil ye is the displacement

of the shaker head and y is the displacement response of the test package

It is assumed that kb has consistent electrical and mechanical units (Vmsec and NA) Usually

the electrical time constant of the shaker is quite small compared with the primarily mechanical

time constants of the shaker and the test package In such cases the Ledie=dt term in Equation 121 may

be neglected Consequently the equations from Equation 119 through Equation 122 may be

expressed in the Laplace (frequency) domain with the Laplace variable s taking the place of the derivative

d=dt as

ethms2 thorn bsthorn kTHORNy frac14 ethbsthorn kTHORNye eth123THORN

FIGURE 19 Dynamic models of an electromagnetic shaker and a flexible test package (a) mechanical model

(b) electrical model

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frac12mes2 thorn ethbthorn beTHORNsthorn ethkthorn keTHORN ye frac14 ethbsthorn kTHORNy thorn kb

Rev2

k2bs

Reye eth124THORN

It follows that the transfer function of the shaker head motion with respect to the excitation voltage is

given by

yevfrac14 kb

Re

DethsTHORNDdethsTHORN eth125THORN

where DethsTHORN is the characteristic function of the primary dynamics of the test object

DethsTHORN frac14 ms2 thorn bsthorn k eth126THORN

and DdethsTHORN is the characteristic function of the primary dynamic interactions between the shaker and thetest object

DcethsTHORN frac14 mmes4 thorn frac12methbe thorn bthorn boTHORN thornmeb s

3 thorn frac12methke thorn kTHORN thornmekthorn bethbe thorn boTHORN s2thorn frac12bke thorn ethbe thorn boTHORNk sthorn kke

eth127THORN

where

bo frac14 k2bRe

eth128THORN

It is clear that under low damping conditions DdethsTHORN will produce two resonances as it is fourth order in sand similarly DethsTHORN will produce one antiresonance (trough) corresponding to the resonance of the testobject Note that in the frequency domain s frac14 jv and hence the frequency response function given by

Equation 125 is in fact

yevfrac14 kb

Rb

DethjvTHORNDdethjvTHORN eth129THORN

The magnitude of this frequency response function for a typical test system is sketched in Figure 110

Note that this curve is for the ldquoopen-looprdquo case where there is no feedback from the shaker controller

In practice the shaker controller will be able

to compensate for the resonances and anti-

resonances to some degree depending on its

effectiveness

The main advantages of electromagnetic

shakers are their high frequency range of

operation their high degree of operating flexi-

bility and the high level of accuracy of the

generated shaker motion Faithful reproduction

of complex excitations is possible because of the

advanced electronics and control systems used in

this type of shakers Electromagnetic shakers are

not suitable for heavy-duty applications (large test

objects) however High test-input accelerations

are possible at high frequencies when electromag-

netic shakers are used but their displacement and

velocity capabilities are limited to low or

intermediate values (see Table 11)

100

10

1 10 100Excitation Frequency (Hz)

Antiresonance

Resonance

Shak

erD

ispl

acem

entM

agni

tude

Resonance

1000

FIGURE 110 Frequency response curve of a typical

electromagnetic shaker with a test object

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1221 Transient Exciters

Other varieties of exciters are commonly used in

transient-type vibration testing In these tests

either an impulsive force or an initial excitation is

applied to the test object and the resulting

response is monitored The excitations and the

responses are ldquotransientrdquo in this case Hammer

test drop tests and pluck tests fall into this

category For example a hammer test may be

conducted by hitting the object with an instru-

mented hammer and then measuring the response

of the object The hammer has a force sensor at its

tip as sketched in Figure 111 A piezoelectric or

strain-gage type force sensor may be used More

sophisticated hammers have impedance heads in

place of force sensors An impedance head

measures force and acceleration simultaneously

The results of a hammer test will depend on many

factors for example the dynamics of the hammer

body how firmly the hammer is held during the

impact how quickly the impact is applied and

whether there are multiple impacts

13 Control System

The two primary functions of the shaker control system in vibration testing are (1) to guarantee that the

specified excitation is applied to the test object and (2) to ensure that the dynamic stability (motion

constraints) of the test setup is preserved An operational block diagram illustrating these control

functions is given in Figure 112 The reference input to the control system represents the desired

excitation force that should be applied to the test object In the absence of any control however the force

reaching the test object will be distorted primarily because of (1) dynamic interactions and

nonlinearities of the shaker the test table the mounting fixtures the auxiliary instruments and the test

object itself (2) noise and errors in the signal generator amplifiers filters and other equipment and (3)

external loads and disturbances acting on the test object and other components (for example external

restraints aerodynamic forces friction) To compensate for these distorting factors response

measurements (displacements velocities acceleration and so on) are made at various locations in the

test setup and are used to control the system dynamics In particular the responses of the shaker the test

table and the test object are measured These responses are used to compare the actual excitation felt by

FIGURE 111 An instrumented hammer used in bump

tests or hammer tests

ExcitationInput

(Reference)

Feedback Paths

DriveSignal

ShakerResponse

TestTable

TestObject

Test ObjectResponse

Test TableResponseExciter

(Shaker)(Ram)

Controllerand

Amplifier

FIGURE 112 Operational block diagram illustrating a general shaker control system

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the test object at the shaker interface with the desired (specified) input The drive signal to the shaker is

modified depending on the error that is present

Two types of control are commonly employed in shaker apparatus simple manual control and

complex automatic control Manual control normally consists of simple open-loop trial-and-error

methods of manual adjustments (or calibration) of the control equipment to obtain a desired dynamic

response The actual response is usually monitored (on an oscilloscope or frequency analyzer screen for

example) during manual-control operations The pretest adjustments in manual control can be very

time-consuming as a result the test object might be subjected to overtesting which could produce

cumulative damage is undesirable and could defeat the test purpose Furthermore the calibration

procedure for the experimental setup must be repeated for each new test object

The disadvantages ofmanual control suggest that automatic control is desirable in complex test schemes

in which high accuracy of testing is desired The first step of automatic control involves automatic

measurement of the system response using control sensors and transducers The measurement is then fed

back into the control system which instantaneously determines the best drive signal to actuate the shaker

in order to get the desired excitation This may be done by either analog or digital methods

Primitive control systems require an accurate mathematical description of the test object This

dependency of the control system on the knowledge of test-object dynamics is clearly undesirable

Performance of a good control system should not be considerably affected by the dynamic interactions

and nonlinearities of the test object or by the nature of the excitation Proper selection of feedback signals

and control-system components can reduce such effects and will make the system robust

In the response-spectrum method of vibration testing it is customary to use displacement control at

low frequencies velocity control at intermediate frequency and acceleration control at high frequencies

This necessitates feedback of displacement velocity and acceleration responses Generally however the

most important feedback is the velocity feedback In sine-sweep tests the shaker velocity must change

steadily over the frequency band of interest In particular the velocity control must be precise near the

resonances of the test object Velocity (speed) feedback has a stabilizing effect on the dynamics which is

desirable This effect is particularly useful in ensuring stability in motion when testing is done near

resonances of lightly damped test objects On the contrary displacement (position) feedback can have a

destabilizing effect on some systems particularly when high feedback gains are used

The controller usually consists of various instruments equipment and computation hardware and

software Often the functions of the data-acquisition and processing system overlap with those of the

controller to some extent As an example consider the digital-controller of vibration testing apparatus

First the responses are measured through sensors (and transducers) filtered and amplified

(conditioned) These data channels may be passed through a multiplexer whose purpose is to select

one data channel at a time for processing Most modern data acquisition hardware does not need a

separate multiplexer to handle multiple signals The analog data are converted into digital data using

analog-to-digital converters (ADCs) The resulting sampled data are stored on a disk or as a block data in

the computer memory The reference input signal (typically a signal recorded on an FM tape) is also

sampled (if it is not already in the digital form) using an ADC and fed into the computer Digital

processing is done on the reference signal and the response data with the objective of computing the

command signal to drive the shaker The digital command signal is converted into an analog signal using

a digital-to-analog converter (DAC) and amplified (conditioned) before it is used to drive the exciter

The nature of the control components depends to a large extent on the nature and objectives of the

particular test to be conducted Some of the basic components in a shaker controller are described in

the following subsections

131 Components of a Shaker Controller

1311 Compressor

A compressor circuit is incorporated in automatic excitation control devices to control the excitation-

input level automatically The level of control depends on the feedback signal from a control sensor and

Vibration Monitoring Testing and Instrumentation1-16

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the specified (reference) excitation signal Usually the compressor circuit is included in the excitation-

signal generator (for example in a sine generator) The control by this means may be done on the basis of

a single-frequency component (eg the fundamental frequency)

1312 Equalizer (Spectrum Shaper)

Random-signal equalizers are used to shape the spectrum of a random signal in a desired manner In

essence and equalizer consists of a bank of narrow-band filters (for example 80 filters) in parallel over

the operating frequency range By passing the signal through each filter the spectral density (or the mean

square value) of the signal in that narrow frequency band (for example each one-third-octave band) is

determined This is compared with the desired spectral level and automatic adjustment is made in that

filter in case there is an error In some systems response-spectrum analysis is made in place of power

spectral density analysis In that case the equalizer consists of a bank of simple oscillators whose

resonant frequencies are distributed over the operating frequency range of the equalizer The feedback

signal is passed through each oscillator and the peak value of its output is determined This value is

compared with the desired response spectrum value at that frequency If there is an error automatic gain

adjustment is made in the appropriate excitation signal components

Random-noise equalizers are used in conjunction with random signal generators They receive

feedback signals from the control sensors In some digital control systems there are algorithms (software)

that are used to iteratively converge the spectrum of the excitation signal felt by the test object into the

desired spectrum

1313 Tracking Filter

Many vibration tests are based on single-frequency excitations In such cases the control functions

should be performed on the basis of the amplitudes of the fundamental-frequency component of the

signal A tracking filter is simply a frequency-tuned band-pass filter It automatically tunes the center

frequency of its very narrow-band-pass filter to the frequency of a carrier signal Then when a noisy

signal is passed through the tuned filter the output of the filter will be the required fundamental

frequency component in the signal Tracking filters also are useful in obtaining amplitudendashfrequency

plots using an XndashY plotter In such cases the frequency value comes from the signal generator (sweep

oscillator) which produces the carrier signal to the tracking filter The tracking filter then determines the

corresponding amplitude of a signal that is fed into it Most tracking filters have dual channels so that two

signals can be handled (tracked) simultaneously

1314 Excitation Controller (Amplitude Servo-Monitor)

An excitation controller is typically an integral part of the signal generator It can be set so that automatic

sweep between two frequency limits can be performed at a selected sweep rate (linear or logarithmic)

More advanced excitation controllers have the capability of an automatic switch-over between constant-

displacement constant-velocity and constant-acceleration excitation-input control at specified

frequencies over the sweep frequency interval Consequently integrator circuits should be present

within the excitation controller unit to determine velocities and displacements from acceleration signals

Sometimes integration is performed by a separate unit called a vibration meter This unit also offers

the operator the capability of selecting the desired level of each signal (acceleration velocity or

displacement) There is an automatic cut-off level for large displacement values that could result from

noise in acceleration signals A compressor is also a subcomponent of the excitation controller The

complete unit is sometimes known as an amplitude servo-monitor

132 Signal-Generating Equipment

Shakers are force-generating devices that are operated using drive (excitation) signals generated from a

source The excitation-signal source is known as the signal generator Three major types of signal

generators are used in vibration testing applications (1) oscillators (2) random-signal generators and

(3) storage devices In some units oscillators and random-signal generators are combined We shall

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discuss these two generators separately however because of their difference in function It also should be

noted that almost any digital signal (deterministic or random) can be generated by a digital computer

using a suitable computer program the signal eventually can be passed through a DAC to obtain

the corresponding analog signal These lsquodigitalrsquo signal generators along with analog sources such as

magnetic tape players (FM) are classified into the category of storage devices

The dynamic range of equipment is the ratio of the maximum and minimum output levels (expressed

in decibels) at which it is capable of operating without significant error This is an important specification

for many types of equipment particularly for signal-generating devices The output level of the signal

generator should be set to a value within its dynamic range

1321 Oscillators

Oscillators are essentially single-frequency generators Typically sine signals are generated but other

waveforms (such as rectangular and triangular pulses) are also available in most oscillators Normally

an oscillator has two modes of operation (1) sweeping up and down between two frequency limits and

(2) dwelling at a specified frequency In the sweep operation the sweep rate should be specified This can

be done either on a linear scale (Hzmin) or on a logarithmic scale (octavesmin) In the dwell operation

the frequency points (or intervals) should be specified In either case a desired signal level can be chosen

using the gain-control knob An oscillator that is operated exclusively in the sweep mode is called a sweep

oscillator

The early generation of oscillators employed variable inductor-capacitor types of electronic circuits to

generate signals oscillating at a desired frequency The oscillator is tuned to the required frequency by

varying the capacitance or inductance parameters A DC voltage is applied to energize the capacitor

and to obtain the desired oscillating voltage signal which subsequently is amplified and conditioned

Modern oscillators use operational amplifier circuits along with resistor capacitor and semiconductor

(SC) elements Also common are crystal (quartz) parallel-resonance oscillators used to generate voltage

signals accurately at a fixed frequency The circuit is activated using a DC-voltage source Other

frequencies of interest are obtained by passing this high-frequency signal through a frequency converter

The signal is then conditioned (amplified and filtered) Required shaping (for example rectangular

pulse) is obtained using a shape circuit Finally the required signal level is obtained by passing the

resulting signal through a variable-gain amplifier A block diagram of an oscillator illustrating various

stages in the generation of a periodic signal is given in Figure 113

A typical oscillator offers a choice of several (typically six) linear and logarithmic frequency ranges and

a sizable level of control capability (for example 80 dB) Upper and lower frequency limits in a sweep can

be preset on the front panel to any of the available frequency ranges Sweep-rate settings are continuously

DC Voltage

Oscillator

FrequencySpecification

FrequencyConverter

FilterAmplifier

ShaperPeriodicSignal

FrequencyCounter

Fixed-FrequencySignal

Variable-GainOutput

Amplifier

SignalSpecification

LevelSpecification

FIGURE 113 Block diagram of an oscillator-type signal generator

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  • 53191fm
    • Vibration Monitoring Testing and Instrumentation
      • Preface
      • Acknowledgments
      • Editor-in-Chief
      • Contributors
      • Contents
      • Related Titles
          • 53191ch1
            • Table of Contents
            • Chapter 1 Vibration Instrumentation
              • Summary
              • 11 Introduction
              • 12 Vibration Exciters
                • 121 Shaker Selection
                  • 1211 Force Rating
                  • 1212 Power Rating
                  • 1213 Stroke Rating
                  • 1214 Hydraulic Shakers
                  • 1215 Inertial Shakers
                  • 1216 Electromagnetic Shakers
                    • 122 Dynamics of Electromagnetic Shakers
                      • 1221 Transient Exciters
                          • 13 Control System
                            • 131 Components of a Shaker Controller
                              • 1311 Compressor
                              • 1312 Equalizer (Spectrum Shaper)
                              • 1313 Tracking Filter
                              • 1314 Excitation Controller (Amplitude Servo-Monitor)
                                • 132 Signal-Generating Equipment
                                  • 1321 Oscillators
                                  • 1322 Random Signal Generators
                                  • 1323 Tape Players
                                  • 1324 Data Processing
                                      • 14 Performance Specification
                                        • 141 Parameters for Performance Specification
                                          • 1411 Time-Domain Specifications
                                          • 1412 Frequency-Domain Specifications
                                            • 142 Linearity
                                            • 143 Instrument Ratings
                                              • 1431 Rating Parameters
                                                • 144 Accuracy and Precision
                                                  • 15 Motion Sensors and Transducers
                                                    • 151 Potentiometer
                                                      • 1511 Potentiometer Resolution
                                                      • 1512 Optical Potentiometer
                                                        • 152 Variable-Inductance Transducers
                                                          • 1521 Mutual-Induction Transducers
                                                          • 1522 Linear-Variable Differential Transformer
                                                          • 1523 Signal Conditioning
                                                            • 153 Mutual-Induction Proximity Sensor
                                                            • 154 Selfinduction Transducers
                                                            • 155 Permanent-Magnet Transducers
                                                            • 156 Alternating Current Permanent-Magnet Tachometer
                                                            • 157 Alternating Current Induction Tachometer
                                                            • 158 Eddy Current Transducers
                                                            • 159 Variable-Capacitance Transducers
                                                              • 1591 Capacitive Displacement Sensors
                                                              • 1592 Capacitive Angular Velocity Sensor
                                                              • 1593 Capacitance Bridge Circuit
                                                                • 1510 Piezoelectric Transducers
                                                                  • 15101 Sensitivity
                                                                  • 15102 Piezoelectric Accelerometer
                                                                  • 15103 Charge Amplifier
                                                                      • 16 Torque Force and Other Sensors
                                                                        • 161 Strain Gage Sensors
                                                                          • 1611 Equations for Strain Gage Measurements
                                                                          • 1612 Bridge Sensitivity
                                                                          • 1613 The Bridge Constant
                                                                          • 1614 The Calibration Constant
                                                                          • 1615 Data Acquisition
                                                                          • 1616 Accuracy Considerations
                                                                          • 1617 Semiconductor Strain Gages
                                                                          • 1618 Force and Torque Sensors
                                                                          • 1619 Strain Gage Torque Sensors
                                                                          • 16110 Deflection Torque Sensors
                                                                          • 16111 Variable-Reluctance Torque Sensor
                                                                          • 16112 Reaction Torque Sensors
                                                                            • 162 Miscellaneous Sensors
                                                                              • 1621 Stroboscope
                                                                              • 1622 Fiber Optic Sensors and Lasers
                                                                              • 1623 Fiber-Optic Gyroscope
                                                                              • 1624 Laser Doppler Interferometer
                                                                              • 1625 Ultrasonic Sensors
                                                                              • 1626 Gyroscopic Sensors
                                                                                  • References
                                                                                  • Appendix 1A Virtual Instrumentation for Data Acquisition Analysis and Presentation
                                                                                    • Summary
                                                                                    • List of Abbreviations
                                                                                    • 1A1 Dynamic Signals
                                                                                      • 1A11 Acquiring and Simulating Dynamic Signals
                                                                                        • 1A111 Aliasing
                                                                                        • 1A112 Time Continuity
                                                                                            • 1A2 Measurement Configuration Considerations
                                                                                              • 1A21 Input Signal Considerations
                                                                                                • 1A211 Input Pseudodifferential and Differential Configuration
                                                                                                • 1A212 Gain
                                                                                                • 1A213 Input Coupling
                                                                                                • 1A214 Integrated Electronic Piezoelectric Excitation
                                                                                                • 1A215 Nyquist Frequency and Bandwidth
                                                                                                • 1A216 Analog-to-Digital Conversion
                                                                                                • 1A217 Antialias Filters
                                                                                                • 1A218 Input Filter Delay
                                                                                                • 1A219 Overload Detection
                                                                                                  • 1A22 Output Signal Considerations
                                                                                                    • 1A221 Output Pseudodifferential and Differential Configuration
                                                                                                    • 1A222 Attenuation
                                                                                                    • 1A223 Digital-to-Analog Conversion
                                                                                                    • 1A224 Anti-imaging and Interpolation Filters
                                                                                                    • 1A225 Output Filter Delay
                                                                                                        • 1A3 Scaling and Calibration
                                                                                                          • 1A31 Scaling to Engineering Units
                                                                                                          • 1A32 Performing System Calibration
                                                                                                            • 1A321 Propagation Delay Calibration
                                                                                                                • 1A4 Limit Testing Analysis
                                                                                                                  • 1A41 Limit Testing Overview
                                                                                                                  • 1A42 Using the SVT Limit Testing VI
                                                                                                                    • 1A5 Integration
                                                                                                                      • 1A51 Introduction to Integration
                                                                                                                      • 1A52 Implementing Integration
                                                                                                                        • 1A521 Challenges when Integrating Vibration Data
                                                                                                                          • 1A53 Time-Domain Integration
                                                                                                                            • 1A531 Single-Shot Acquisition and Integration
                                                                                                                            • 1A532 Continuous Acquisition and Integration
                                                                                                                              • 1A54 Frequency-Domain Integration
                                                                                                                                • 1A6 Vibration-Level Measurements
                                                                                                                                  • 1A61 Measuring the Root Mean Square Level
                                                                                                                                    • 1A611 Single-Shot Buffered Acquisition
                                                                                                                                    • 1A612 Continuous Signal Acquisition
                                                                                                                                      • 1A62 Performing a Running RMS Level Measurement
                                                                                                                                      • 1A63 Computing the Peak Level
                                                                                                                                      • 1A64 Computing the Crest Factor
                                                                                                                                        • 1A7 Frequency Analysis
                                                                                                                                          • 1A71 FFT Fundamentals
                                                                                                                                            • 1A711 Number of Samples
                                                                                                                                            • 1A712 Frequency Resolution
                                                                                                                                            • 1A713 Maximum Resolvable Frequency
                                                                                                                                            • 1A714 Minimum Resolvable Frequency
                                                                                                                                            • 1A715 Number of Spectral Lines
                                                                                                                                            • 1A716 Relationship between Time-Domain and Frequency-Domain Specifications and Parameters
                                                                                                                                              • 1A72 Increasing Frequency Resolution
                                                                                                                                                • 1A721 Zoom FFT Analysis
                                                                                                                                                • 1A722 Frequency Resolution of the Zoom FFT VIs
                                                                                                                                                • 1A723 Zoom Measurement
                                                                                                                                                • 1A724 Zoom Settings
                                                                                                                                                • 1A725 Subset Analysis
                                                                                                                                                    • 1A8 Transient Analysis
                                                                                                                                                      • 1A81 Transient Analysis with the Sound and Vibration Toolkit
                                                                                                                                                      • 1A82 Performing an STFT vs Time
                                                                                                                                                        • 1A821 Selecting the FFT Block Size
                                                                                                                                                        • 1A822 Overlapping
                                                                                                                                                        • 1A823 Using the SVT STFT vs Time VI
                                                                                                                                                          • 1A83 Performing an STFT vs Rotational Speed
                                                                                                                                                            • 1A831 Converting the Pulse Train to Rotational Speed
                                                                                                                                                            • 1A832 STFT vs RPM
                                                                                                                                                              • 1A84 Measuring a Shock Response Spectrum
                                                                                                                                                                • 1A9 Waterfall Display
                                                                                                                                                                  • 1A91 Using the Display VIs
                                                                                                                                                                    • 1A911 Initializing the Display
                                                                                                                                                                    • 1A912 Sending Data to the Display
                                                                                                                                                                    • 1A913 Waterfall Display for Frequency Analysis
                                                                                                                                                                    • 1A914 Waterfall Display for Transient Analysis
                                                                                                                                                                    • 1A915 Waterfall Display for Octave Spectra
                                                                                                                                                                        • 1A10 Swept-Sine Measurements
                                                                                                                                                                          • 1A101 Swept-Sine Overview
                                                                                                                                                                          • 1A102 Choosing Swept-Sine vs FFT Measurements
                                                                                                                                                                          • 1A103 Taking a Swept-Sine Measurement
                                                                                                                                                                          • 1A104 Swept-Sine Measurement Example
                                                                                                                                                                              • Bibliography
                                                                                                                                                                              • Related Titles
                                                                                                                                                                                  • 53191ch2
                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                    • Chapter 2 Signal Conditioning and Modification
                                                                                                                                                                                      • Summary
                                                                                                                                                                                      • 21 Introduction
                                                                                                                                                                                      • 22 Amplifiers
                                                                                                                                                                                        • 221 Operational Amplifier
                                                                                                                                                                                        • 222 Use of Feedback in Opamp
                                                                                                                                                                                        • 223 Voltage Current and Power Amplifiers
                                                                                                                                                                                          • 2231 Charge Amplifiers
                                                                                                                                                                                            • 224 Instrumentation Amplifiers
                                                                                                                                                                                              • 2241 Differential Amplifier
                                                                                                                                                                                              • 2242 Common Mode
                                                                                                                                                                                                • 225 Amplifier Performance Ratings
                                                                                                                                                                                                  • 2251 Common-Mode Rejection Ratio
                                                                                                                                                                                                    • 226 Component Interconnection
                                                                                                                                                                                                      • 2261 Impedance Characteristics
                                                                                                                                                                                                      • 2262 Cascade Connection of Devices
                                                                                                                                                                                                      • 2263 AC-Coupled Ampliers
                                                                                                                                                                                                          • 23 Analog Filters
                                                                                                                                                                                                            • 231 Passive Filters and Active Filters
                                                                                                                                                                                                              • 2311 Number of Poles
                                                                                                                                                                                                                • 232 Low-Pass Filters
                                                                                                                                                                                                                  • 2321 Low-Pass Butterworth Filter
                                                                                                                                                                                                                    • 233 High-Pass Filters
                                                                                                                                                                                                                    • 234 Band-Pass Filters
                                                                                                                                                                                                                      • 2341 Resonance-Type Band-Pass Filters
                                                                                                                                                                                                                        • 235 Band-Reject Filters
                                                                                                                                                                                                                          • 24 Modulators and Demodulators
                                                                                                                                                                                                                            • 241 Amplitude Modulation
                                                                                                                                                                                                                              • 2411 Modulation Theorem
                                                                                                                                                                                                                              • 2412 Side Frequencies and Side Bands
                                                                                                                                                                                                                                • 242 Application of Amplitude Modulation
                                                                                                                                                                                                                                  • 2421 Fault Detection and Diagnosis
                                                                                                                                                                                                                                    • 243 Demodulation
                                                                                                                                                                                                                                      • 25 Analog ndashDigital Conversion
                                                                                                                                                                                                                                        • 251 Digital-to-Analog Conversion
                                                                                                                                                                                                                                          • 2511 DAC Error Sources
                                                                                                                                                                                                                                            • 252 Analog-to-Digital Conversion
                                                                                                                                                                                                                                            • 253 Analog-to-Digital Converter Performance Characteristics
                                                                                                                                                                                                                                              • 2531 Resolution and Quantization Error
                                                                                                                                                                                                                                              • 2532 Monotonicity Nonlinearity and Offset Error
                                                                                                                                                                                                                                              • 2533 Analog-to-Digital Converter Conversion Rate
                                                                                                                                                                                                                                                • 254 Sample-and-Hold Circuitry
                                                                                                                                                                                                                                                • 255 Digital Filters
                                                                                                                                                                                                                                                  • 2551 Software Implementation and Hardware Implementation
                                                                                                                                                                                                                                                      • 26 Bridge Circuits
                                                                                                                                                                                                                                                        • 261 Wheatstone Bridge
                                                                                                                                                                                                                                                        • 262 Constant-Current Bridge
                                                                                                                                                                                                                                                        • 263 Bridge Amplifiers
                                                                                                                                                                                                                                                          • 2631 Half-Bridge Circuits
                                                                                                                                                                                                                                                            • 264 Impedance Bridges
                                                                                                                                                                                                                                                              • 2641 Owen Bridge
                                                                                                                                                                                                                                                              • 2642 Wien-Bridge Oscillator
                                                                                                                                                                                                                                                                  • 27 Linearizing Devices
                                                                                                                                                                                                                                                                    • 271 Linearization by Software
                                                                                                                                                                                                                                                                    • 272 Linearization by Hardware Logic
                                                                                                                                                                                                                                                                    • 273 Analog Linearizing Circuitry
                                                                                                                                                                                                                                                                    • 274 Offsetting Circuitry
                                                                                                                                                                                                                                                                    • 275 Proportional-Output Circuitry
                                                                                                                                                                                                                                                                      • 2751 Curve-Shaping Circuitry
                                                                                                                                                                                                                                                                          • 28 Miscellaneous Signal Modification Circuitry
                                                                                                                                                                                                                                                                            • 281 Phase Shifters
                                                                                                                                                                                                                                                                            • 282 Voltage-to-Frequency Converter
                                                                                                                                                                                                                                                                            • 283 Frequency-to-Voltage Converter
                                                                                                                                                                                                                                                                            • 284 Voltage-to-Current Converters
                                                                                                                                                                                                                                                                            • 285 Peak-Hold Circuits
                                                                                                                                                                                                                                                                              • 29 Signal Analyzers and Display Devices
                                                                                                                                                                                                                                                                                • 291 Signal Analyzers
                                                                                                                                                                                                                                                                                • 292 Oscilloscopes
                                                                                                                                                                                                                                                                                  • 2921 Triggering
                                                                                                                                                                                                                                                                                  • 2922 Lissajous Patterns
                                                                                                                                                                                                                                                                                  • 2923 Digital Oscilloscopes
                                                                                                                                                                                                                                                                                      • Bibliography
                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                          • 53191ch3
                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                            • Chapter 3 Vibration Testing
                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                              • 31 Introduction
                                                                                                                                                                                                                                                                                              • 32 Representation of a Vibration Environment
                                                                                                                                                                                                                                                                                                • 321 Test Signals
                                                                                                                                                                                                                                                                                                  • 3211 Stochastic vs Deterministic Signals
                                                                                                                                                                                                                                                                                                    • 322 Deterministic Signal Representation
                                                                                                                                                                                                                                                                                                      • 3221 Single-Frequency Signals
                                                                                                                                                                                                                                                                                                      • 3222 Sine Sweep
                                                                                                                                                                                                                                                                                                      • 3223 Sine Dwell
                                                                                                                                                                                                                                                                                                      • 3224 Decaying Sine
                                                                                                                                                                                                                                                                                                      • 3225 Sine Beat
                                                                                                                                                                                                                                                                                                      • 3226 Sine Beat with Pauses
                                                                                                                                                                                                                                                                                                      • 3227 Multifrequency Signals
                                                                                                                                                                                                                                                                                                      • 3228 Actual Excitation Records
                                                                                                                                                                                                                                                                                                      • 3229 Simulated Excitation Signals
                                                                                                                                                                                                                                                                                                        • 323 Stochastic Signal Representation
                                                                                                                                                                                                                                                                                                          • 3231 Ergodic Random Signals
                                                                                                                                                                                                                                                                                                          • 3232 Stationary Random Signals
                                                                                                                                                                                                                                                                                                          • 3233 Independent and Uncorrelated Signals
                                                                                                                                                                                                                                                                                                          • 3234 Transmission of Random Excitations
                                                                                                                                                                                                                                                                                                            • 324 Frequency-Domain Representations
                                                                                                                                                                                                                                                                                                              • 3241 Fourier Spectrum Method
                                                                                                                                                                                                                                                                                                              • 3242 Power Spectral Density Method
                                                                                                                                                                                                                                                                                                                • 325 Response Spectrum
                                                                                                                                                                                                                                                                                                                  • 3251 Displacement Velocity and Acceleration Spectra
                                                                                                                                                                                                                                                                                                                  • 3252 Response-Spectra Plotting Paper
                                                                                                                                                                                                                                                                                                                  • 3253 Zero-Period Acceleration
                                                                                                                                                                                                                                                                                                                  • 3254 Uses of Response Spectra
                                                                                                                                                                                                                                                                                                                    • 326 Comparison of Various Representations
                                                                                                                                                                                                                                                                                                                      • 33 Pretest Procedures
                                                                                                                                                                                                                                                                                                                        • 331 Purpose of Testing
                                                                                                                                                                                                                                                                                                                        • 332 Service Functions
                                                                                                                                                                                                                                                                                                                          • 3321 Active Equipment
                                                                                                                                                                                                                                                                                                                          • 3322 Passive Equipment
                                                                                                                                                                                                                                                                                                                          • 3323 Functional Testing
                                                                                                                                                                                                                                                                                                                            • 333 Information Acquisition
                                                                                                                                                                                                                                                                                                                              • 3331 Interface Details
                                                                                                                                                                                                                                                                                                                              • 3332 Effect of Neglecting Interface Dynamics
                                                                                                                                                                                                                                                                                                                              • 3333 Effects of Damping
                                                                                                                                                                                                                                                                                                                              • 3334 Effects of Inertia
                                                                                                                                                                                                                                                                                                                              • 3335 Effect of Natural Frequency
                                                                                                                                                                                                                                                                                                                              • 3336 Effect of Excitation Frequency
                                                                                                                                                                                                                                                                                                                              • 3337 Other Effects of Interface
                                                                                                                                                                                                                                                                                                                                • 334 Test-Program Planning
                                                                                                                                                                                                                                                                                                                                  • 3341 Testing of Cabinet-Mounted Equipment
                                                                                                                                                                                                                                                                                                                                    • 335 Pretest Inspection
                                                                                                                                                                                                                                                                                                                                      • 34 Testing Procedures
                                                                                                                                                                                                                                                                                                                                        • 341 Resonance Search
                                                                                                                                                                                                                                                                                                                                        • 342 Methods of Determining Frequency-Response Functions
                                                                                                                                                                                                                                                                                                                                          • 3421 Fourier Transform Method
                                                                                                                                                                                                                                                                                                                                          • 3422 Spectral Density Method
                                                                                                                                                                                                                                                                                                                                          • 3423 Harmonic Excitation Method
                                                                                                                                                                                                                                                                                                                                            • 343 Resonance-Search Test Methods
                                                                                                                                                                                                                                                                                                                                              • 3431 Hammer (Bump) Test and Drop Test
                                                                                                                                                                                                                                                                                                                                              • 3432 Pluck Test
                                                                                                                                                                                                                                                                                                                                              • 3433 Shaker Tests
                                                                                                                                                                                                                                                                                                                                                • 344 Mechanical Aging
                                                                                                                                                                                                                                                                                                                                                  • 3441 Equivalence for Mechanical Aging
                                                                                                                                                                                                                                                                                                                                                  • 3442 Excitation-Intensity Equivalence
                                                                                                                                                                                                                                                                                                                                                  • 3443 Dynamic-Excitation Equivalence
                                                                                                                                                                                                                                                                                                                                                  • 3444 Cumulative Damage Theory
                                                                                                                                                                                                                                                                                                                                                    • 345 Test-Response Spectrum Generation
                                                                                                                                                                                                                                                                                                                                                    • 346 Instrument Calibration
                                                                                                                                                                                                                                                                                                                                                    • 347 Test-Object Mounting
                                                                                                                                                                                                                                                                                                                                                    • 348 Test-Input Considerations
                                                                                                                                                                                                                                                                                                                                                      • 3481 Test Nomenclature
                                                                                                                                                                                                                                                                                                                                                      • 3482 Testing with Uncorrelated Excitations
                                                                                                                                                                                                                                                                                                                                                      • 3483 Symmetrical Rectilinear Testing
                                                                                                                                                                                                                                                                                                                                                      • 3484 Geometry vs Dynamics
                                                                                                                                                                                                                                                                                                                                                      • 3485 Some Limitations
                                                                                                                                                                                                                                                                                                                                                      • 3486 Testing Black Boxes
                                                                                                                                                                                                                                                                                                                                                      • 3487 Phasing of Excitations
                                                                                                                                                                                                                                                                                                                                                      • 3488 Testing a Gray or White Box
                                                                                                                                                                                                                                                                                                                                                      • 3489 Overtesting in Multitest Sequences
                                                                                                                                                                                                                                                                                                                                                          • 35 Some Practical Information
                                                                                                                                                                                                                                                                                                                                                            • 351 Random Vibration Test Example
                                                                                                                                                                                                                                                                                                                                                            • 352 Vibration Shakers and Control Systems
                                                                                                                                                                                                                                                                                                                                                              • Bibliography
                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                  • 53191ch4
                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                    • Chapter 4 Experimental Modal Analysis
                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                      • 41 Introduction
                                                                                                                                                                                                                                                                                                                                                                      • 42 Frequency-Domain Formulation
                                                                                                                                                                                                                                                                                                                                                                        • 421 Transfer-Function Matrix
                                                                                                                                                                                                                                                                                                                                                                        • 422 Principle of Reciprocity
                                                                                                                                                                                                                                                                                                                                                                          • 43 Experimental Model Development
                                                                                                                                                                                                                                                                                                                                                                            • 431 Extraction of the Time-Domain Model
                                                                                                                                                                                                                                                                                                                                                                              • 44 Curve Fitting of Transfer Functions
                                                                                                                                                                                                                                                                                                                                                                                • 441 Problem Identification
                                                                                                                                                                                                                                                                                                                                                                                • 442 Single- and Multi-Degree-of-Freedom Techniques
                                                                                                                                                                                                                                                                                                                                                                                • 443 Single-Degree-of-Freedom Parameter Extraction in the Frequency Domain
                                                                                                                                                                                                                                                                                                                                                                                  • 4431 Circle-Fit Method
                                                                                                                                                                                                                                                                                                                                                                                    • Case of Viscous Damping
                                                                                                                                                                                                                                                                                                                                                                                    • Case of Hysteretic Damping
                                                                                                                                                                                                                                                                                                                                                                                      • 4432 Peak-Picking Method
                                                                                                                                                                                                                                                                                                                                                                                        • 444 Multi-Degree of Freedom Curve Fitting
                                                                                                                                                                                                                                                                                                                                                                                          • 4441 Formulation of the Method
                                                                                                                                                                                                                                                                                                                                                                                            • 445 A Comment on Static Modes and Rigid-Body Modes
                                                                                                                                                                                                                                                                                                                                                                                            • 446 Residue Extraction
                                                                                                                                                                                                                                                                                                                                                                                              • 45 Laboratory Experiments
                                                                                                                                                                                                                                                                                                                                                                                                • 451 Lumped-Parameter System
                                                                                                                                                                                                                                                                                                                                                                                                  • 4511 Frequency-Domain Test
                                                                                                                                                                                                                                                                                                                                                                                                  • 4512 Time-Domain Tests
                                                                                                                                                                                                                                                                                                                                                                                                    • 452 Distributed-Parameter System
                                                                                                                                                                                                                                                                                                                                                                                                      • 46 Commercial EMA Systems
                                                                                                                                                                                                                                                                                                                                                                                                        • 461 System Configuration
                                                                                                                                                                                                                                                                                                                                                                                                          • 4611 FFT Analysis Options
                                                                                                                                                                                                                                                                                                                                                                                                          • 4612 Modal Analysis Components
                                                                                                                                                                                                                                                                                                                                                                                                              • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                  • 53191ch5
                                                                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                    • Chapter 5 Mechanical Shock
                                                                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                      • 51 Definitions
                                                                                                                                                                                                                                                                                                                                                                                                                        • 511 Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 512 Simple (or Perfect) Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 513 Half-Sine Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 514 Versed-Sine (or Haversine) Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 515 Terminal Peak Sawtooth Shock or Final Peak Sawtooth Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 516 Rectangular Shock
                                                                                                                                                                                                                                                                                                                                                                                                                          • 5161 Trapezoidal Shock
                                                                                                                                                                                                                                                                                                                                                                                                                              • 52 Description in the Time Domain
                                                                                                                                                                                                                                                                                                                                                                                                                              • 53 Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                • 531 Need
                                                                                                                                                                                                                                                                                                                                                                                                                                • 532 Shock Response Spectrum Definition
                                                                                                                                                                                                                                                                                                                                                                                                                                • 533 Response of a Linear One-Degree-of-Freedom System
                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5331 Shock Defined by a Force
                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5332 Shock Defined by an Acceleration
                                                                                                                                                                                                                                                                                                                                                                                                                                    • 534 Definitions
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5341 Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5342 Absolute Acceleration Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5343 Relative Displacement Shock Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5344 Primary Positive Shock Response Spectrum or Initial Positive Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5345 Primary (or Initial) Negative Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5346 Secondary (or Residual) Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5347 Positive (or Maximum Positive) Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5348 Negative (or Maximum Negative) Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5349 Maximax Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53410 Choice of Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                        • 535 Standardized Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5351 Definition
                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5352 Standardized Shock Response Spectra of Simple Shocks
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53521 Half-Sine Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53522 Versed Sine Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53523 Terminal Peak Sawtooth Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53524 Rectangular Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53525 Trapezoidal Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 536 Choice of Damping
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 537 Shock Response Spectra Domains
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 538 Algorithms for Calculation of the Shock Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 539 Choice of the Digitization Frequency of the Signal
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5310 Use of Shock Response Spectra for the Study of Systems with Several Degrees of Freedom
                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 54 Pyroshocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 55 Use of Shock Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 551 Severity Comparison of Several Shocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 552 Test Specification Development from Real Environment Data
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5521 Synthesis of Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5522 Nature of the Specification
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5523 Choice of Shape
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5524 Amplitude
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5525 Duration
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5526 Difficulties
                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 56 Standards
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 561 Types of Standards
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 562 Installation Conditions of Test Item
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 563 Uncertainty Factor
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 564 Bump Test
                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 57 Damage Boundary Curve
                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 571 Definition
                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 572 Analysis of Test Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 58 Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 581 Main Types
                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 582 Impact Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5821 Universal Shock-Test Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 58211 Impact Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 58212 Impulse Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 583 Shock Simulators (Programmers)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5831 Half-Sine Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58311 Shock Duration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58312 Impact Velocity
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58313 Maximum Deformation of the Shock Simulator (Programmer)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58314 Shock Amplitude
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58315 Characteristics of the Target
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5832 Terminal Peak Sawtooth Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5833 Rectangular Pulse ndash Trapezoidal Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5834 Universal Shock Simulator (Programmer)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 58341 Generating a Half-Sine Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 58342 Generating a Terminal Peak Sawtooth Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 58343 Trapezoidal Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 584 Limitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5841 Limitations of the Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5842 Limitations of Shock Simulators
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 585 Pneumatic Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 586 High Impact Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5861 Lightweight High Impact Shock Machine
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5862 Medium Weight High Impact Shock Machine
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 587 Specific Test Facilities
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 59 Generation of Shock Using Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 591 Principle Behind the Generation of a Simple Shape Signal versus Time
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 592 Main Advantages
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 593 Pre- and Postshocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5931 Requirements
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5932 Solutions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 59321 Optimized Pre- and Postpulses
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5933 Incidence on the Shock Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 594 Limitations of Electrodynamic Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5941 Mechanical Limitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 59411 Abacuses
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5942 Electronic Limitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 595 The Use of Electrohydraulic Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 510 Control by a Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 5101 Principle
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 5102 Principal Shapes of Elementary Signals
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 51021 Decaying Sinusoid
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 51022 ZERD Function
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 51023 WAVSIN Waveform
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 5103 Comparison of WAVSIN SHOC Waveforms and Decaying Sinusoid
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 5104 Criticism of Control by a Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 511 Pyrotechnic Shock Simulation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5111 Simulation Using Pyrotechnic Facilities
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5112 Simulation Using Metal-to-Metal Impact
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5113 Simulation Using Electrodynamic Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5114 Simulation Using Conventional Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53191ch6
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Chapter 6 Machine Condition Monitoring and Fault Diagnostics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 61 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 62 Machinery Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 621 Causes of Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 622 Types of Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 623 Frequency of Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 63 Basic Maintenance Strategies
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 631 Run-to-Failure (Breakdown) Maintenance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 632 Scheduled (Preventative) Maintenance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 633 Condition-Based (Predictive Proactive Reliability Centered On-Condition) Maintenance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 64 Factors Which Influence Maintenance Strategy
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 65 Machine Condition Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 651 Periodic Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 652 Continuous Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 66 Transducer Selection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 661 Noncontact Displacement Transducers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 662 Velocity Transducers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 663 Acceleration Transducers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 67 Transducer Location
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 68 Recording and Analysis Instrumentation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 681 Vibration Meters
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 682 Data Collectors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 683 Frequency-Domain Analyzers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 684 Time-Domain Instruments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 685 Tracking Analyzers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 69 Display Formats and Analysis Tools
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 691 Time Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6911 Time-Waveform Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6912 Time-Waveform Indices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6913 Time-Synchronous Averaging
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6914 Negative Averaging
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6915 Orbits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6916 Probability Density Functions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6917 Probability Density Moments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 692 Frequency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6921 Band-Pass Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6922 Shock Pulse (Spike Energy)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6923 Enveloped Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6924 Signature Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6925 Cascades (Waterfall Plots)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6926 Masks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6927 Frequency-Domain Indices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 693 Modal Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 694 Quefrency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 610 Fault Detection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 6101 Standards
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61011 Standards Based on Machinery Type
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61012 Standards Based on Vibration Severity
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 6102 Acceptance Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 61021 Statistical Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 6103 Frequency-Domain Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61031 Limited Band Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61032 Constant Bandwidth Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61033 Constant Percentage Bandwidth Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 611 Fault Diagnostics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 6111 Forcing Functions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61111 Unbalance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61112 Misalignment
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61113 Mechanical Looseness
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61114 Soft Foot
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61115 Rubs
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61116 Resonances
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61117 Oil Whirl
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61118 Oil Whip
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61119 Structural Vibrations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 611110 Foundation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 6112 Specific Machine Components
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 61121 Damaged or Worn Rolling-Element Bearings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 61122 Damaged or Worn Gears
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 6113 Specific Machine Types
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61131 Pumps
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61132 Fans
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61133 Electric Motors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61134 Steam and Gas Turbines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61135 Compressors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61136 Reciprocating Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 6114 Advanced Fault Diagnostic Techniques
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 53191ch7
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • Chapter 7 Vibration-Based Tool Condition Monitoring Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 71 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 72 Mechanics of Turning
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 721 General Terms
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 722 Chatter Vibrations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 723 Tool Wear
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7231 Tool Failure Mechanisms
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7232 Tool Failure Modes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7233 Tool Wear Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7234 Tool Wear Stages
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 73 Vibration Signal Recording
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 731 Direct and Indirect Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 732 Sensor Requirements for Tool Wear Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 733 Force Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7331 Direct Measurement Dynamometers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7332 Indirect Force Sensors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7333 Piezoelectric Strain Sensors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7334 Resistance Strain Gauges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7335 Customized Force Sensors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 734 Acceleration Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 735 Acoustic Emission Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 736 Sensor Comparisons
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 74 Signal Processing for Sensor-Based Tool Condition Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 741 Feature Extraction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7411 Time Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7412 Frequency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7413 Statistical Processing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7414 TimendashFrequency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 742 Feature Selection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 75 Wear ModelDecision-Making for Sensor-Based Tool Condition Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 751 Trending Threshold
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 752 Neural Networks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7521 Unsupervised Networks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7522 Supervised Networks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 753 Fuzzy Logic
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 754 Other Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 76 Conclusion
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53191ch8
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Chapter 8 Fault Diagnosis of Helicopter Gearboxes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 81 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 82 Abnormality Scaling
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 83 The Structure-Based Connectionist Network
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 84 Sensor Location Selection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 841 Coverage Index
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 842 Overlap Index
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 843 Monitoring Effectiveness
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 85 A Case Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 851 Structural and Featural Influences
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 852 Evaluation of Influences
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 853 Fault Detection Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 854 Fault Diagnostic Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 8541 Faulty Subsystem Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 8542 Faulty Component Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 855 Sensor Location Evaluation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 856 Sensor Location Validation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 86 Conclusion
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 53191ch9
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Chapter 9 Vibration Suppression and Monitoring in Precision Motion Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 91 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 92 Mechanical Design to Minimize Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 921 Stability and Static Determinacy of Machine Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 922 Two-Dimensional Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 923 Three-Dimensional Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 93 Adaptive Notch Filter
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 931 Fast Fourier Transform
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 932 Simulation and Experiments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 94 Real-Time Vibration Analyzer
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 941 Learning Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 942 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 943 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 944 Experiments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 9441 Input Variables mdash the Evaluation Criteria
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 94411 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 94412 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 9442 Evaluation Rules
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 94421 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 94422 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 9443 Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 94431 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 94432 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 95 Practical Insights and Case Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 96 Conclusions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 53191ch10
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Chapter 10 Vibration and Shock Problems of Civil Engineering Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 101 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 102 Earthquake-Induced Vibration of Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1021 Seismicity and Ground Motions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1022 Influence of Local Site Conditions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1023 Response of Structures to Ground Motions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1024 Dynamic Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10241 Equations of Motion for Linear Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10242 Equations of Motion for Linear Multiple-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1025 Earthquake Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10251 Elastic Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10252 Smoothed Design Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10253 Ductility-Modified Response Spectrum Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1026 Design Philosophy and the Code Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10261 Performance-Based Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1027 Analysis Options for Earthquake Effects
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10271 Dynamic Time History Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10272 Response Spectrum Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 102721 Response Spectrum Analysis of Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 102722 Response Spectrum Analysis of Multi-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10273 Equivalent Static Analysis (Force-Based Approach)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10274 Displacement-Based Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1028 SoilndashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1029 Active and Passive Control Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 10210 Worked Examples
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 103 Dynamic Effects of Wind Loading on Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1031 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1032 Wind Speed
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1033 Design Structures for Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10331 Types of Wind Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10332 Design Criteria
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10333 Static Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1034 Along and Across-Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10341 Along-Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10342 Across-Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1035 Wind Tunnel Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1036 Comfort Criteria Human Response to Building Motion
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1037 Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1038 Comparison with Earthquake Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 104 Vibrations Due to Fluid ndashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1041 Added Mass and Inertial Coupling
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1042 Wave-Induced Vibration of Structure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 105 Blast Loading and Blast Effects on Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1051 Explosions and Blast Phenomenon
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1052 Explosive Air-Blast Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10521 Blast Wave Scaling Laws
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10522 Prediction of Blast Pressure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1053 Gas Explosion Loading and Effect of Internal Explosions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1054 Structural Response to Blast Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10541 Elastic Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10542 Elasto-Plastic Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1055 Material Behaviors at High Strain Rate
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10551 Dynamic Properties of Concrete under High Strain Rates
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10552 Dynamic Properties of Reinforcing Steel under High Strain Rates
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1056 Failure Modes of Blast-Loaded Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10561 Global Structural Behavior
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10562 Localized Structural Behavior
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10563 PressurendashImpulse ( PndashI ) Diagrams
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1057 Blast WavendashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1058 Effect of Ground Shocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10581 Loads from Air-Induced Ground Shock
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10582 Loads from Direct Ground Shock
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1059 Technical Design Manuals for Blast-Resistant Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 10510 Computer Programs for Blast and Shock Effects
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 106 Impact Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1061 Structural Impact between Two Bodies mdash Hard Impact and Soft Impact
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1062 Example mdash Aircraft Impact
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 107 Floor Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1071 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1072 Types of Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10721 Walking
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10722 Rhythmic Activities
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10723 Mechanical Equipment
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10724 Analysis Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1073 Natural Frequency of Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10731 Computing the Natural Frequency
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10732 Computing Deflection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10733 Damping
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10734 Resonance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1074 Vibration Caused by Walking
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10741 Minimum Natural Frequency
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1075 Design for Rhythmic Excitation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10751 Harmonics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10752 Minimum Natural Frequency
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1076 Example mdash Vibration Analysis of a Reinforced Concrete Floor
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 53191ch11
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Chapter 11 Seismic Base Isolation and Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 111 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1111 From Ductility Design to Base Isolation and Control Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1112 The Importance of Reducing Seismic Input and Response
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 112 Seismic Base Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1121 Historical Development of Base Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1122 Basic Principle
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1123 Issues in Seismic Base Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11231 Performance Criteria
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11232 Type of Structure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11233 Site Characteristics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11234 Retrofit Issues
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11235 Design of Building Services
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11236 Expected Life of Isolator
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1124 Seismic Isolation Devices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11241 Laminated Rubber Bearings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11242 Lead Rubber Bearing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11243 Friction-Based Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11244 Other Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1125 Design of Isolation Devices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11251 High-Damping Rubber Bearing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112511 Stability against Buckling
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112512 Stability against Roll Out
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11252 Lead Rubber Bearings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112521 Design of Lead Plug
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112522 Design of Laminated Rubber Bearing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11253 Design of Friction Pendulum System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1126 Verification of Properties of Isolation Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11261 Tests for Isolation Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 112611 System Characterization Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 112612 Prototype Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 112613 Quality Control Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11262 Uniform Building Code Recommendations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112621 Units Dependent on Loading Rates
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112622 Units Dependent on Bilateral Load
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112623 System Adequacy
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1127 Analysis of Base-Isolated Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11271 Modeling of a Superstructure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11272 Modeling of Isolation System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11273 Static Analysis Procedure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11274 Dynamic Analysis Procedure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 112741 Response Spectrum Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 112742 Time-History Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11275 Software for Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1128 Experimental Methods for Isolated Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1129 Implementation of Seismic Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11291 New Construction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112911 Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112912 Bridges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11292 Seismic Retrofit
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112921 Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112922 Bridges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11293 Other Implementations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 11210 Performance during Past Earthquakes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 112101 Performance of Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 112102 Performance of Bridges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 113 Seismic Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1131 Historical Development of Seismic Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1132 Basic Principles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11321 Passive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11322 Active Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11323 Semiactive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11324 Hybrid Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11325 Categorization of Basic Principles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1133 Important Issues in Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11331 SoilndashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11332 DevicendashStructure Interaction and Time Delay
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11333 Design Guidelines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1134 Vibration-Control Devices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11341 Passive Control Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113411 Metallic Yielding Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113412 Friction Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113413 Viscoelastic Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113414 Viscous Fluid Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113415 Tuned Mass Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11342 Active Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113421 Electromagnetic Actuator
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113422 Hydraulic Actuators
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11343 Semiactive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113431 Variable-Orifice Hydraulic Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113432 Controllable Fluid Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113433 Controllable Friction Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11344 Hybrid Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1135 Control Algorithm
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11351 Active Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11352 Semiactive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113521 Common Control Schemes for Controllable Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113522 Special Control Schemes for Controllable Damper
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1136 Experimental Performance Verification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11361 Shaking Table Tests of a Flexible Structural Model with TMD AMD and ATMD
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11362 Substructure Hybrid Test
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113621 Hybrid Tests Using Hydraulic Actuator
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113622 Hybrid Tests Using Shaking Table
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113623 Hybrid Tests Using Inertia-Force-Driven Loading System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1137 Implementations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11371 Semiactive Control of Full-Scale Structures Using Variable Joint Damper System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113711 Background of Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113712 Test System Set Up
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113713 Control Algorithm
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113714 Test Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11372 Application of Structural Control Technologies to Seismic Retrofit of a Cable-Stayed Bridge
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113721 Background of Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113722 Basic Concept of Seismic Retrofit
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113723 Modal Shape Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113724 Time-History Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113725 Soil ndash Structure Interaction Effect
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113726 Semiactive Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53191ch12
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Chapter 12 Seismic Random Vibration of Long-Span Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 121 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1211 Basic Concepts of Random Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12111 Stationary Random Process
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12112 Nonstationary Random Process
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1212 Three Methods for Structural Seismic Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12121 Response Spectrum Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12122 Time-History Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12123 Random Vibration Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 121231 Davenport Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 121232 Vanmarcke Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 12124 Comparisons of the Three Seismic-Analysis Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 122 Seismic Random-Excitation Fields
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1221 Power Spectral Density of Spatially Varying Ground Acceleration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1222 Several Coherence Models
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12221 FengndashHu Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12222 Harichandran ndashVanmarcke Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12223 LohndashYeh Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12224 OliveirandashHaondashPenzien Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12225 LucondashWong Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12226 QundashWangndashWang Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1223 Generation of Ground Acceleration Power Spectral Density Curves from Acceleration Response Spectrum Curves
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12231 Kaul Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12232 Iteration Scheme
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1224 Seismic Equations of Motion of Long-Span Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1225 Seismic Waves and Their Geometrical Expressions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 123 Pseudoexcitation Method for Structural Random Vibration Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1231 Structures Subjected to Stationary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12311 Single Stationary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12312 Multiple Stationary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1232 Structures Subjected to Nonstationary Random Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12321 Structures Subjected to Uniformly Modulated Evolutionary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 123211 Single Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 123212 Multiple Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12322 Structures Subjected to Nonuniformly Modulated Evolutionary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 123221 Single Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 123222 Multiple Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1233 Precise Integration Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12331 Precise Integration of Exponential Matrices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12332 Particular Solutions and Precise Integration Formulas for Various Forms of Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 123321 Linear Loading Form (HPD-L Form)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 123322 Sinusoidal Loading Form (HPD-S Form)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 123323 Exponentially Decaying Sinusoidal Loading Form (HPD-E Form)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 124 Long-Span Structures Subjected to Stationary Random Ground Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1241 The Solution of Equations of Motion Using the Pseudoexcitation Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1242 Numerical Comparisons with Other Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12421 Song-Hua-Jiang Suspension Bridge
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 124211 All Supports Move Uniformly
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 124212 Wave Passage Effect Is Taken into Account
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 124213 Wave-Passage Effect and Incoherence Effect Are Jointly Taken into Account
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 12422 San Joaquin Concrete Bridge
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 125 Long-Span Structures Subjected to Nonstationary Random Ground Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1251 Modulation Functions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1252 The Formulas for Nonstationary Multiexcitation Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1253 Expected Extreme Values of Nonstationary Random Processes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1254 Numerical Comparisons with the Corresponding Stationary Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 126 Conclusions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Related Titles
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                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Chapter 13 Seismic Qualification of Equipment
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 131 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 132 Distribution Qualification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1321 Drive-Signal Generation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1322 Distribution Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1323 Test Procedures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 133 Seismic Qualification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1331 Stages of Seismic Qualification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1332 Test Preliminaries
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1333 Single-Frequency Testing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1334 Multifrequency Testing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1335 Generation of RRS Specifications
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 53191ch14
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Chapter 14 Human Response to Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 141 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 142 Vibration Excitations on Humans
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1421 Excitation Characteristics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 143 Human Response to Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1431 Vibration Perception
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1432 Frequency Weighting Curve
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1433 Iso-Perception Curves
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1434 Detection Threshold Curve
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 144 Regulation of Human Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1441 Acceptable Vibration Levels in Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1442 Whole-Body Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1443 HandndashArm Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
Page 19: Vibration Monitoring, Testing, and Instrumentationpreview.kingborn.net › 646000 › d1a74678d91943e5ba1d5e... · The MEMS Handbook, Second Edition MEMS: Introduction and Fundamentals

1211 Force Rating

In the frequency domain the (complex) force at the exciter (shaker) head is given by

F frac14 mHethvTHORNasethvTHORN eth16THORNin which v is the excitation frequency variable m is the total mass of the test package including

mounting fixture and attachments asethvTHORN is the Fourier spectrum of the support-location (exciter head)

acceleration and H(v) is frequency response function that takes into account the flexibility and

damping effects (dynamics) of the test package apart from its inertia In the simplified case where the

test package can be represented by a simple oscillator of natural frequency vn and damping ratio by zt

this function becomes

HethvTHORN frac14 1thorn 2jztv=vn=12 ethv=vnTHORN2 thorn 2jztv=vn eth17THORNin which j frac14 ffiffiffiffi

21p

This approximation is adequate for most practical purposes The static weight of the

test object is not included in Equation 16 Most heavy-duty shakers which are typically hydraulic

have static load support systems such as pneumatic cushion arrangements that can exactly balance the

dead load The exciter provides only the dynamic force In cases where shaker directly supports the

gravity load in the vertical test configuration Equation 16 should be modified by adding a term to

represent this weight

A common practice in vibration test applications is to specify the excitation signal by its response

spectrum This is simply the peak response of a simple oscillator expressed as a function of its natural

frequency when its support location is excited by the specified signal Clearly the damping of the simple

oscillator is an added parameter in a response spectrum specification Typical damping ratios ethzrTHORN used inresponse spectra specifications are less than 01 (or 10) It follows that an approximate relationship

between the Fourier spectrum of the support acceleration and its response spectrum is

as frac14 2jzrarethvTHORN eth18THORNThe magnitude larethvTHORNl is the response spectrumEquation 18 substituted into Equation 16 gives

F frac14 mHethvTHORN2jzrarethvTHORN eth19THORNIn view of Equation 17 for test packages having low damping the peak value of H(v) is

approximately 1=eth2jztTHORN this should be used in computing the force rating if the test package has a

resonance within the frequency range of testing On the other hand if the test package is assumed to be

rigid then HethvTHORN oslash 1 A conservative estimate for the force rating is

Fmax frac14 methzr=ztTHORNlarethvTHORNlmax eth110THORNIt should be noted that larethvTHORNlmax is the peak value of the specified (required) response spectrum (RRS)

for acceleration

1212 Power Rating

The exciter head does not develop its maximum force when driven at maximum velocity Output power

is determined by using

p frac14 Refrac12FvsethvTHORN eth111THORNin which vsethvTHORN is the Fourier spectrum of the exciter velocity and Re [ ] denotes the real part of a complex

function Note that as frac14 jvvs Substituting Equation 16 and Equation 18 into Equation 111 gives

p frac14 eth4mz2r =vTHORNRefrac12jHethvTHORNa2r ethvTHORN eth112THORNIt follows that a conservative estimate for the power rating is

pmax frac14 2methz2r =ztTHORNfrac12larethvTHORNl2=v max eth113THORN

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Representative segments of typical acceleration RRS curves have slope n as given by

a frac14 k1vn eth114THORN

It should be clear from Equation 113 that the maximum output power is given by

pmax frac14 k2v2n21 eth115THORN

This is an increasing function for n 1=2 and a decreasing function for n 1=2 It follows that the power

rating corresponds to the highest point of contact between the acceleration RRS curve and a line of slope

equal to 12 A similar relationship may be derived if velocity RRS curves (having slopes n2 1) are used

1213 Stroke Rating

From Equation 18 it should be clear that the Fourier spectrum xs of the exciter displacement time

history can be expressed as

xs frac14 2zrarethvTHORN=jv2 eth116THORNAn estimate for stroke rating is

xmax frac14 2zrfrac12larethvTHORNl=v2 max eth117THORNThis is of the form

xmax frac14 kvn22 eth118THORNIt follows that the stroke rating corresponds to the highest point of contact between the acceleration

RRS curve and a line of slope equal to two

Example 11

A test package of overall mass 100 kg is to be

subjected to dynamic excitation represented by the

acceleration RRS (at 5 damping) as shown in

Figure 14 The estimated damping of the test

package is 7 The test package is known to have a

resonance within the frequency range of the

specified test Determine the exciter specifications

for the test

Solution

From the development presented in the previous

section it is clear that the point F (or P) in

Figure 14 corresponds to the force and output

power ratings and the point S corresponds to

the stroke rating The co-ordinates of these

critical points are F P frac14 eth42 Hz 40 gTHORN and S frac14 eth08 Hz 075 gTHORN Equation 110 gives the force

rating as

Fmax frac14 100 pound eth005=007THORN pound 40 pound 981 N frac14 2803 N

Equation 113 gives the power rating as

pmax frac14 2 pound 100 pound eth0052=007THORN pound frac12eth40 pound 981THORN2=42 pound 2p watts frac14 417 W

Equation 117 gives the stroke rating as

xmax frac14 2 pound 005 pound frac12eth075 pound 98THORN=eth08 pound 2pTHORN2 m frac14 3 cm

Acc

eler

atio

n(g

)

Con

stan

t Dis

plac

emen

t

Constant Velo

city

Frequency (Hz)

S

FP

0101

10 10 100

10

10

FIGURE 14 Test excitation specified by an accelera-

tion RRS (5 damping)

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1214 Hydraulic Shakers

A typical hydraulic shaker consists of a piston-cylinder arrangement (also called a ram) a servo-valve a

fluid pump and a driving electric motor Hydraulic fluid (oil) is pressurized (typical operating pressure

4000 psi) and pumped into the cylinder through a servo-valve by means of a pump that is driven by an

electric motor (typical power 150 hp) The flow (typical rate 100 galmin) that enters the cylinder is

controlled (modulated) by the servo-valve which in effect controls the resulting piston (ram) motion

A typical servo-valve consists of a two-stage spool valve which provides a pressure difference and a

controlled (modulated) flow to the piston which sets it in motion

The servo-valve itself is moved by means of a linear torque motor which is driven by the excitation-

input signal (electrical) A primary function of the servo-valve is to provide a stabilizing feedback to the

ram In this respect the servo-valve complements the main control system of the test setup The ram is

coupled to the shaker table by means of a link with some flexibility The cylinder frame is mounted on the

support foundation with swivel joints This allows for some angular and lateral misalignment which

might be caused primarily by test-object dynamics as the table moves

Two-degree-of-freedom (Two-DoF) testing requires two independent sets of actuators and three-DoF

testing requires three independent actuator sets Each independent actuator set can consist of several

actuators operated in parallel using the same pump and the same excitation-input signal to the torque

motors

If the test table is directly supported on the vertical actuators they must withstand the total dead

weight (ie the weight of the test table the test object the mounting fixtures and the instrumentation)

This is requirement is usually prevented by providing a pressurized air cushion in the gap between the

test table and the foundation walls Air should be pressurized so as to balance the total dead weight

exactly (typical required gage pressure 3 psi)

Figure 15(a) shows the basic components of a typical hydraulic shaker The corresponding

operational block diagram is shown in Figure 15(b) It is desirable to locate the actuators in a pit in the

test laboratory so that the test tabletop is flushed with the test laboratory floor under no-load conditions

This minimizes the effort required to place the test object on the test table Otherwise the test object has

to be lifted onto the test table with a forklift Also installation of an aircushion to support the system

dead weight is difficult under these circumstances of elevated mounting

Hydraulic actuators are most suitable for heavy load testing and are widely used in industrial and civil

engineering applications They canbeoperated at very low frequencies (almost direct current [DC]) aswell

as at intermediate frequencies (see Table 11) Large displacements (stroke) are possible at low frequencies

Hydraulic shakers have the advantage of providing high flexibility of operation during the test their

capabilities include variable-force and constant-force testing and wide-band random-input testing The

velocity and acceleration capabilities of hydraulic shakers are moderate Although any general excitation-

input motion (for example sine wave sine beat wide-band random) can be used in hydraulic shakers

faithful reproduction of these signals is virtually impossible at high frequencies because of distortion and

higher-order harmonics introduced by the high noise levels that are common in hydraulic systems This

is only a minor drawback in heavy-duty intermediate-frequency applications Dynamic interactions are

reduced through feedback control

1215 Inertial Shakers

In inertial shakers or ldquomechanical excitersrdquo the force that causes the shaker-table motion is generated by

inertia forces (accelerating masses) Counter-rotating-mass inertial shakers are typical in this category

To understand their principle of operation consider two equal masses rotating in opposite directions at

the same angular speed v and in the same circle of radius r (see Figure 16) This produces a resultant

force equal to 2mv2r cos vt in a fixed direction (the direction of symmetry of the two rotating arms)

Consequently a sinusoidal force with a frequency of v and an amplitude proportional to v2 is generated

This reaction force is applied to the shaker table

Figure 17 shows a sketch of a typical counter-rotating-mass inertial shaker It consists of two identical

rods rotating at the same speed in opposite directions Each rod has a series of slots in which to

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place weights In this manner the magnitude of

the eccentric mass can be varied to achieve various

force capabilities The rods are driven by a

variable-speed electric motor through a gear

mechanism that usually provides several speed

ratios A speed ratio is selected depending on the

required test-frequency range The whole system is

symmetrically supported on a carriage that is

directly connected to the test table The test object

is mounted on the test table The preferred

mounting configuration is horizontal so that the

excitation force is applied to the test object in a

horizontal direction In this configuration there

are no variable gravity moments (weight pounddistance to center of gravity) acting on the drive

mechanism Figure 17 shows the vertical con-

figuration In dynamic testing of large structures

the carriage can be mounted directly on the

structure at a location where the excitation force

should be applied By incorporating two pairs of

counter-rotating masses it is possible to generate

test moments as well as test forces

FIGURE 15 A typical hydraulic shaker arrangement (a) schematic diagram (b) operational block diagram

m m

2mw2r cos wt

wtw w

wt

FIGURE 16 Principle of operation of a counter-

rotating-mass inertial shaker

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Reaction-type shakers driven by inertia are widely used for the prototype testing of civil engineering

structures Their first application dates back to 1935 Inertial shakers are capable of producing

intermediate excitation forces The force generated is limited by the strength of the carriage frame The

frequency range of operation and the maximum velocity and acceleration capabilities are also

intermediate for inertial shakers whereas the maximum displacement capability is typically low A major

limitation of inertial shakers is that their excitation force is exclusively sinusoidal and that the force

amplitude is directly proportional to the square of the excitation frequency As a result complex and

random excitation testing constant-force testing (for example transmissibility tests and constant-force

sine-sweep tests) and flexibility to vary the force amplitude or the displacement amplitude during a test

are not generally feasible with this type of shakers Excitation frequency and amplitude can be varied

during testing however by incorporating a variable-speed drive for the motor The sinusoidal excitation

generated by inertial shakers is virtually undistorted which gives them an advantage over the other types

of shakers when used in sine-dwell and sine-sweep tests Small portable shakers with low-force capability

are available for use in on-site testing

1216 Electromagnetic Shakers

In electromagnetic shakers or ldquoelectrodynamic excitersrdquo the motion is generated using the principle of

operation of an electric motor Specifically the excitation force is produced when a variable excitation

signal (electrical) is passed through a moving coil placed in a magnetic field

The components of a commercial electromagnetic shaker are shown in Figure 18 A steady magnetic

field is generated by a stationary electromagnet that consists of field coils wound on a ferromagnetic base

that is rigidly attached to a protective shell structure The shaker head has a coil wound around it When

the excitation electrical signal is passed through this drive coil the shaker head which is supported on

flexure mounts will be set in motion The shaker head consists of the test table on which the test object

is mounted Shakers with interchangeable heads are available The choice of appropriate shaker head is

based on the geometry and mounting features of the test object The shaker head can be turned to

different angles by means of a swivel joint In this manner different directions of excitation (in biaxial

and triaxial testing) can be obtained

FIGURE 17 Sketch of a counter-rotating-mass inertial shaker

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122 Dynamics of Electromagnetic Shakers

Consider a single axis electromagnetic shaker (Figure 18) with a test object having a single natural

frequency of importance within the test frequency range The dynamic interactions between the shaker

and the test object give rise to two significant natural frequencies (and correspondingly two significant

resonances) These appear as peaks in the frequency response curve of the test setup Furthermore the

natural frequency (resonance) of the test package alone causes a ldquotroughrdquo or depression (antiresonance)

in the frequency response curve of the overall test setup To explain this characteristic consider the

dynamic model shown in Figure 19 The following mechanical parameters are defined for

Figure 19(a) m k and b are the mass stiffness and equivalent viscous damping constant respectively

of the test package and me ke and be are the corresponding parameters of the exciter (shaker) Also in

the equivalent electrical circuit of the shaker head as shown in Figure 19(b) the following electrical

parameters are defined Re and Le are the resistance and (leakage) inductance and kb is the back

electromotive force (back emf) of the linear motor Assuming that the gravitational forces are supported

FIGURE 18 Schematic sectional view of a typical electromagnetic shaker manufactured by Bruel and Kjaer

Denmark

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by the static deflections of the flexible elements and that the displacements are measured from the static

equilibrium position we have the following system equations

Test object meuroy frac14 2kethy2 yeTHORN2 beth_y2 _yeTHORN eth119THORNShaker head me euroye frac14 fe thorn kethy2 yeTHORN thorn beth_y2 _yeTHORN2 key 2 be _ye eth120THORN

Electrical Lediedt

thorn Reie thorn kb _ye frac14 vethtTHORN eth121THORN

The electromagnetic force fe generated in the shaker head is a result of the interaction of the magnetic

field generated by the current ie with coil of the moving shaker head and the constant magnetic field

(stator) in which the head coil is located Here we have

fe frac14 kbie eth122THORNNote that v(t) is the voltage signal that is applied by the amplifier to the shaker coil ye is the displacement

of the shaker head and y is the displacement response of the test package

It is assumed that kb has consistent electrical and mechanical units (Vmsec and NA) Usually

the electrical time constant of the shaker is quite small compared with the primarily mechanical

time constants of the shaker and the test package In such cases the Ledie=dt term in Equation 121 may

be neglected Consequently the equations from Equation 119 through Equation 122 may be

expressed in the Laplace (frequency) domain with the Laplace variable s taking the place of the derivative

d=dt as

ethms2 thorn bsthorn kTHORNy frac14 ethbsthorn kTHORNye eth123THORN

FIGURE 19 Dynamic models of an electromagnetic shaker and a flexible test package (a) mechanical model

(b) electrical model

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frac12mes2 thorn ethbthorn beTHORNsthorn ethkthorn keTHORN ye frac14 ethbsthorn kTHORNy thorn kb

Rev2

k2bs

Reye eth124THORN

It follows that the transfer function of the shaker head motion with respect to the excitation voltage is

given by

yevfrac14 kb

Re

DethsTHORNDdethsTHORN eth125THORN

where DethsTHORN is the characteristic function of the primary dynamics of the test object

DethsTHORN frac14 ms2 thorn bsthorn k eth126THORN

and DdethsTHORN is the characteristic function of the primary dynamic interactions between the shaker and thetest object

DcethsTHORN frac14 mmes4 thorn frac12methbe thorn bthorn boTHORN thornmeb s

3 thorn frac12methke thorn kTHORN thornmekthorn bethbe thorn boTHORN s2thorn frac12bke thorn ethbe thorn boTHORNk sthorn kke

eth127THORN

where

bo frac14 k2bRe

eth128THORN

It is clear that under low damping conditions DdethsTHORN will produce two resonances as it is fourth order in sand similarly DethsTHORN will produce one antiresonance (trough) corresponding to the resonance of the testobject Note that in the frequency domain s frac14 jv and hence the frequency response function given by

Equation 125 is in fact

yevfrac14 kb

Rb

DethjvTHORNDdethjvTHORN eth129THORN

The magnitude of this frequency response function for a typical test system is sketched in Figure 110

Note that this curve is for the ldquoopen-looprdquo case where there is no feedback from the shaker controller

In practice the shaker controller will be able

to compensate for the resonances and anti-

resonances to some degree depending on its

effectiveness

The main advantages of electromagnetic

shakers are their high frequency range of

operation their high degree of operating flexi-

bility and the high level of accuracy of the

generated shaker motion Faithful reproduction

of complex excitations is possible because of the

advanced electronics and control systems used in

this type of shakers Electromagnetic shakers are

not suitable for heavy-duty applications (large test

objects) however High test-input accelerations

are possible at high frequencies when electromag-

netic shakers are used but their displacement and

velocity capabilities are limited to low or

intermediate values (see Table 11)

100

10

1 10 100Excitation Frequency (Hz)

Antiresonance

Resonance

Shak

erD

ispl

acem

entM

agni

tude

Resonance

1000

FIGURE 110 Frequency response curve of a typical

electromagnetic shaker with a test object

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1221 Transient Exciters

Other varieties of exciters are commonly used in

transient-type vibration testing In these tests

either an impulsive force or an initial excitation is

applied to the test object and the resulting

response is monitored The excitations and the

responses are ldquotransientrdquo in this case Hammer

test drop tests and pluck tests fall into this

category For example a hammer test may be

conducted by hitting the object with an instru-

mented hammer and then measuring the response

of the object The hammer has a force sensor at its

tip as sketched in Figure 111 A piezoelectric or

strain-gage type force sensor may be used More

sophisticated hammers have impedance heads in

place of force sensors An impedance head

measures force and acceleration simultaneously

The results of a hammer test will depend on many

factors for example the dynamics of the hammer

body how firmly the hammer is held during the

impact how quickly the impact is applied and

whether there are multiple impacts

13 Control System

The two primary functions of the shaker control system in vibration testing are (1) to guarantee that the

specified excitation is applied to the test object and (2) to ensure that the dynamic stability (motion

constraints) of the test setup is preserved An operational block diagram illustrating these control

functions is given in Figure 112 The reference input to the control system represents the desired

excitation force that should be applied to the test object In the absence of any control however the force

reaching the test object will be distorted primarily because of (1) dynamic interactions and

nonlinearities of the shaker the test table the mounting fixtures the auxiliary instruments and the test

object itself (2) noise and errors in the signal generator amplifiers filters and other equipment and (3)

external loads and disturbances acting on the test object and other components (for example external

restraints aerodynamic forces friction) To compensate for these distorting factors response

measurements (displacements velocities acceleration and so on) are made at various locations in the

test setup and are used to control the system dynamics In particular the responses of the shaker the test

table and the test object are measured These responses are used to compare the actual excitation felt by

FIGURE 111 An instrumented hammer used in bump

tests or hammer tests

ExcitationInput

(Reference)

Feedback Paths

DriveSignal

ShakerResponse

TestTable

TestObject

Test ObjectResponse

Test TableResponseExciter

(Shaker)(Ram)

Controllerand

Amplifier

FIGURE 112 Operational block diagram illustrating a general shaker control system

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the test object at the shaker interface with the desired (specified) input The drive signal to the shaker is

modified depending on the error that is present

Two types of control are commonly employed in shaker apparatus simple manual control and

complex automatic control Manual control normally consists of simple open-loop trial-and-error

methods of manual adjustments (or calibration) of the control equipment to obtain a desired dynamic

response The actual response is usually monitored (on an oscilloscope or frequency analyzer screen for

example) during manual-control operations The pretest adjustments in manual control can be very

time-consuming as a result the test object might be subjected to overtesting which could produce

cumulative damage is undesirable and could defeat the test purpose Furthermore the calibration

procedure for the experimental setup must be repeated for each new test object

The disadvantages ofmanual control suggest that automatic control is desirable in complex test schemes

in which high accuracy of testing is desired The first step of automatic control involves automatic

measurement of the system response using control sensors and transducers The measurement is then fed

back into the control system which instantaneously determines the best drive signal to actuate the shaker

in order to get the desired excitation This may be done by either analog or digital methods

Primitive control systems require an accurate mathematical description of the test object This

dependency of the control system on the knowledge of test-object dynamics is clearly undesirable

Performance of a good control system should not be considerably affected by the dynamic interactions

and nonlinearities of the test object or by the nature of the excitation Proper selection of feedback signals

and control-system components can reduce such effects and will make the system robust

In the response-spectrum method of vibration testing it is customary to use displacement control at

low frequencies velocity control at intermediate frequency and acceleration control at high frequencies

This necessitates feedback of displacement velocity and acceleration responses Generally however the

most important feedback is the velocity feedback In sine-sweep tests the shaker velocity must change

steadily over the frequency band of interest In particular the velocity control must be precise near the

resonances of the test object Velocity (speed) feedback has a stabilizing effect on the dynamics which is

desirable This effect is particularly useful in ensuring stability in motion when testing is done near

resonances of lightly damped test objects On the contrary displacement (position) feedback can have a

destabilizing effect on some systems particularly when high feedback gains are used

The controller usually consists of various instruments equipment and computation hardware and

software Often the functions of the data-acquisition and processing system overlap with those of the

controller to some extent As an example consider the digital-controller of vibration testing apparatus

First the responses are measured through sensors (and transducers) filtered and amplified

(conditioned) These data channels may be passed through a multiplexer whose purpose is to select

one data channel at a time for processing Most modern data acquisition hardware does not need a

separate multiplexer to handle multiple signals The analog data are converted into digital data using

analog-to-digital converters (ADCs) The resulting sampled data are stored on a disk or as a block data in

the computer memory The reference input signal (typically a signal recorded on an FM tape) is also

sampled (if it is not already in the digital form) using an ADC and fed into the computer Digital

processing is done on the reference signal and the response data with the objective of computing the

command signal to drive the shaker The digital command signal is converted into an analog signal using

a digital-to-analog converter (DAC) and amplified (conditioned) before it is used to drive the exciter

The nature of the control components depends to a large extent on the nature and objectives of the

particular test to be conducted Some of the basic components in a shaker controller are described in

the following subsections

131 Components of a Shaker Controller

1311 Compressor

A compressor circuit is incorporated in automatic excitation control devices to control the excitation-

input level automatically The level of control depends on the feedback signal from a control sensor and

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the specified (reference) excitation signal Usually the compressor circuit is included in the excitation-

signal generator (for example in a sine generator) The control by this means may be done on the basis of

a single-frequency component (eg the fundamental frequency)

1312 Equalizer (Spectrum Shaper)

Random-signal equalizers are used to shape the spectrum of a random signal in a desired manner In

essence and equalizer consists of a bank of narrow-band filters (for example 80 filters) in parallel over

the operating frequency range By passing the signal through each filter the spectral density (or the mean

square value) of the signal in that narrow frequency band (for example each one-third-octave band) is

determined This is compared with the desired spectral level and automatic adjustment is made in that

filter in case there is an error In some systems response-spectrum analysis is made in place of power

spectral density analysis In that case the equalizer consists of a bank of simple oscillators whose

resonant frequencies are distributed over the operating frequency range of the equalizer The feedback

signal is passed through each oscillator and the peak value of its output is determined This value is

compared with the desired response spectrum value at that frequency If there is an error automatic gain

adjustment is made in the appropriate excitation signal components

Random-noise equalizers are used in conjunction with random signal generators They receive

feedback signals from the control sensors In some digital control systems there are algorithms (software)

that are used to iteratively converge the spectrum of the excitation signal felt by the test object into the

desired spectrum

1313 Tracking Filter

Many vibration tests are based on single-frequency excitations In such cases the control functions

should be performed on the basis of the amplitudes of the fundamental-frequency component of the

signal A tracking filter is simply a frequency-tuned band-pass filter It automatically tunes the center

frequency of its very narrow-band-pass filter to the frequency of a carrier signal Then when a noisy

signal is passed through the tuned filter the output of the filter will be the required fundamental

frequency component in the signal Tracking filters also are useful in obtaining amplitudendashfrequency

plots using an XndashY plotter In such cases the frequency value comes from the signal generator (sweep

oscillator) which produces the carrier signal to the tracking filter The tracking filter then determines the

corresponding amplitude of a signal that is fed into it Most tracking filters have dual channels so that two

signals can be handled (tracked) simultaneously

1314 Excitation Controller (Amplitude Servo-Monitor)

An excitation controller is typically an integral part of the signal generator It can be set so that automatic

sweep between two frequency limits can be performed at a selected sweep rate (linear or logarithmic)

More advanced excitation controllers have the capability of an automatic switch-over between constant-

displacement constant-velocity and constant-acceleration excitation-input control at specified

frequencies over the sweep frequency interval Consequently integrator circuits should be present

within the excitation controller unit to determine velocities and displacements from acceleration signals

Sometimes integration is performed by a separate unit called a vibration meter This unit also offers

the operator the capability of selecting the desired level of each signal (acceleration velocity or

displacement) There is an automatic cut-off level for large displacement values that could result from

noise in acceleration signals A compressor is also a subcomponent of the excitation controller The

complete unit is sometimes known as an amplitude servo-monitor

132 Signal-Generating Equipment

Shakers are force-generating devices that are operated using drive (excitation) signals generated from a

source The excitation-signal source is known as the signal generator Three major types of signal

generators are used in vibration testing applications (1) oscillators (2) random-signal generators and

(3) storage devices In some units oscillators and random-signal generators are combined We shall

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copy 2007 by Taylor amp Francis Group LLC

discuss these two generators separately however because of their difference in function It also should be

noted that almost any digital signal (deterministic or random) can be generated by a digital computer

using a suitable computer program the signal eventually can be passed through a DAC to obtain

the corresponding analog signal These lsquodigitalrsquo signal generators along with analog sources such as

magnetic tape players (FM) are classified into the category of storage devices

The dynamic range of equipment is the ratio of the maximum and minimum output levels (expressed

in decibels) at which it is capable of operating without significant error This is an important specification

for many types of equipment particularly for signal-generating devices The output level of the signal

generator should be set to a value within its dynamic range

1321 Oscillators

Oscillators are essentially single-frequency generators Typically sine signals are generated but other

waveforms (such as rectangular and triangular pulses) are also available in most oscillators Normally

an oscillator has two modes of operation (1) sweeping up and down between two frequency limits and

(2) dwelling at a specified frequency In the sweep operation the sweep rate should be specified This can

be done either on a linear scale (Hzmin) or on a logarithmic scale (octavesmin) In the dwell operation

the frequency points (or intervals) should be specified In either case a desired signal level can be chosen

using the gain-control knob An oscillator that is operated exclusively in the sweep mode is called a sweep

oscillator

The early generation of oscillators employed variable inductor-capacitor types of electronic circuits to

generate signals oscillating at a desired frequency The oscillator is tuned to the required frequency by

varying the capacitance or inductance parameters A DC voltage is applied to energize the capacitor

and to obtain the desired oscillating voltage signal which subsequently is amplified and conditioned

Modern oscillators use operational amplifier circuits along with resistor capacitor and semiconductor

(SC) elements Also common are crystal (quartz) parallel-resonance oscillators used to generate voltage

signals accurately at a fixed frequency The circuit is activated using a DC-voltage source Other

frequencies of interest are obtained by passing this high-frequency signal through a frequency converter

The signal is then conditioned (amplified and filtered) Required shaping (for example rectangular

pulse) is obtained using a shape circuit Finally the required signal level is obtained by passing the

resulting signal through a variable-gain amplifier A block diagram of an oscillator illustrating various

stages in the generation of a periodic signal is given in Figure 113

A typical oscillator offers a choice of several (typically six) linear and logarithmic frequency ranges and

a sizable level of control capability (for example 80 dB) Upper and lower frequency limits in a sweep can

be preset on the front panel to any of the available frequency ranges Sweep-rate settings are continuously

DC Voltage

Oscillator

FrequencySpecification

FrequencyConverter

FilterAmplifier

ShaperPeriodicSignal

FrequencyCounter

Fixed-FrequencySignal

Variable-GainOutput

Amplifier

SignalSpecification

LevelSpecification

FIGURE 113 Block diagram of an oscillator-type signal generator

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  • 53191fm
    • Vibration Monitoring Testing and Instrumentation
      • Preface
      • Acknowledgments
      • Editor-in-Chief
      • Contributors
      • Contents
      • Related Titles
          • 53191ch1
            • Table of Contents
            • Chapter 1 Vibration Instrumentation
              • Summary
              • 11 Introduction
              • 12 Vibration Exciters
                • 121 Shaker Selection
                  • 1211 Force Rating
                  • 1212 Power Rating
                  • 1213 Stroke Rating
                  • 1214 Hydraulic Shakers
                  • 1215 Inertial Shakers
                  • 1216 Electromagnetic Shakers
                    • 122 Dynamics of Electromagnetic Shakers
                      • 1221 Transient Exciters
                          • 13 Control System
                            • 131 Components of a Shaker Controller
                              • 1311 Compressor
                              • 1312 Equalizer (Spectrum Shaper)
                              • 1313 Tracking Filter
                              • 1314 Excitation Controller (Amplitude Servo-Monitor)
                                • 132 Signal-Generating Equipment
                                  • 1321 Oscillators
                                  • 1322 Random Signal Generators
                                  • 1323 Tape Players
                                  • 1324 Data Processing
                                      • 14 Performance Specification
                                        • 141 Parameters for Performance Specification
                                          • 1411 Time-Domain Specifications
                                          • 1412 Frequency-Domain Specifications
                                            • 142 Linearity
                                            • 143 Instrument Ratings
                                              • 1431 Rating Parameters
                                                • 144 Accuracy and Precision
                                                  • 15 Motion Sensors and Transducers
                                                    • 151 Potentiometer
                                                      • 1511 Potentiometer Resolution
                                                      • 1512 Optical Potentiometer
                                                        • 152 Variable-Inductance Transducers
                                                          • 1521 Mutual-Induction Transducers
                                                          • 1522 Linear-Variable Differential Transformer
                                                          • 1523 Signal Conditioning
                                                            • 153 Mutual-Induction Proximity Sensor
                                                            • 154 Selfinduction Transducers
                                                            • 155 Permanent-Magnet Transducers
                                                            • 156 Alternating Current Permanent-Magnet Tachometer
                                                            • 157 Alternating Current Induction Tachometer
                                                            • 158 Eddy Current Transducers
                                                            • 159 Variable-Capacitance Transducers
                                                              • 1591 Capacitive Displacement Sensors
                                                              • 1592 Capacitive Angular Velocity Sensor
                                                              • 1593 Capacitance Bridge Circuit
                                                                • 1510 Piezoelectric Transducers
                                                                  • 15101 Sensitivity
                                                                  • 15102 Piezoelectric Accelerometer
                                                                  • 15103 Charge Amplifier
                                                                      • 16 Torque Force and Other Sensors
                                                                        • 161 Strain Gage Sensors
                                                                          • 1611 Equations for Strain Gage Measurements
                                                                          • 1612 Bridge Sensitivity
                                                                          • 1613 The Bridge Constant
                                                                          • 1614 The Calibration Constant
                                                                          • 1615 Data Acquisition
                                                                          • 1616 Accuracy Considerations
                                                                          • 1617 Semiconductor Strain Gages
                                                                          • 1618 Force and Torque Sensors
                                                                          • 1619 Strain Gage Torque Sensors
                                                                          • 16110 Deflection Torque Sensors
                                                                          • 16111 Variable-Reluctance Torque Sensor
                                                                          • 16112 Reaction Torque Sensors
                                                                            • 162 Miscellaneous Sensors
                                                                              • 1621 Stroboscope
                                                                              • 1622 Fiber Optic Sensors and Lasers
                                                                              • 1623 Fiber-Optic Gyroscope
                                                                              • 1624 Laser Doppler Interferometer
                                                                              • 1625 Ultrasonic Sensors
                                                                              • 1626 Gyroscopic Sensors
                                                                                  • References
                                                                                  • Appendix 1A Virtual Instrumentation for Data Acquisition Analysis and Presentation
                                                                                    • Summary
                                                                                    • List of Abbreviations
                                                                                    • 1A1 Dynamic Signals
                                                                                      • 1A11 Acquiring and Simulating Dynamic Signals
                                                                                        • 1A111 Aliasing
                                                                                        • 1A112 Time Continuity
                                                                                            • 1A2 Measurement Configuration Considerations
                                                                                              • 1A21 Input Signal Considerations
                                                                                                • 1A211 Input Pseudodifferential and Differential Configuration
                                                                                                • 1A212 Gain
                                                                                                • 1A213 Input Coupling
                                                                                                • 1A214 Integrated Electronic Piezoelectric Excitation
                                                                                                • 1A215 Nyquist Frequency and Bandwidth
                                                                                                • 1A216 Analog-to-Digital Conversion
                                                                                                • 1A217 Antialias Filters
                                                                                                • 1A218 Input Filter Delay
                                                                                                • 1A219 Overload Detection
                                                                                                  • 1A22 Output Signal Considerations
                                                                                                    • 1A221 Output Pseudodifferential and Differential Configuration
                                                                                                    • 1A222 Attenuation
                                                                                                    • 1A223 Digital-to-Analog Conversion
                                                                                                    • 1A224 Anti-imaging and Interpolation Filters
                                                                                                    • 1A225 Output Filter Delay
                                                                                                        • 1A3 Scaling and Calibration
                                                                                                          • 1A31 Scaling to Engineering Units
                                                                                                          • 1A32 Performing System Calibration
                                                                                                            • 1A321 Propagation Delay Calibration
                                                                                                                • 1A4 Limit Testing Analysis
                                                                                                                  • 1A41 Limit Testing Overview
                                                                                                                  • 1A42 Using the SVT Limit Testing VI
                                                                                                                    • 1A5 Integration
                                                                                                                      • 1A51 Introduction to Integration
                                                                                                                      • 1A52 Implementing Integration
                                                                                                                        • 1A521 Challenges when Integrating Vibration Data
                                                                                                                          • 1A53 Time-Domain Integration
                                                                                                                            • 1A531 Single-Shot Acquisition and Integration
                                                                                                                            • 1A532 Continuous Acquisition and Integration
                                                                                                                              • 1A54 Frequency-Domain Integration
                                                                                                                                • 1A6 Vibration-Level Measurements
                                                                                                                                  • 1A61 Measuring the Root Mean Square Level
                                                                                                                                    • 1A611 Single-Shot Buffered Acquisition
                                                                                                                                    • 1A612 Continuous Signal Acquisition
                                                                                                                                      • 1A62 Performing a Running RMS Level Measurement
                                                                                                                                      • 1A63 Computing the Peak Level
                                                                                                                                      • 1A64 Computing the Crest Factor
                                                                                                                                        • 1A7 Frequency Analysis
                                                                                                                                          • 1A71 FFT Fundamentals
                                                                                                                                            • 1A711 Number of Samples
                                                                                                                                            • 1A712 Frequency Resolution
                                                                                                                                            • 1A713 Maximum Resolvable Frequency
                                                                                                                                            • 1A714 Minimum Resolvable Frequency
                                                                                                                                            • 1A715 Number of Spectral Lines
                                                                                                                                            • 1A716 Relationship between Time-Domain and Frequency-Domain Specifications and Parameters
                                                                                                                                              • 1A72 Increasing Frequency Resolution
                                                                                                                                                • 1A721 Zoom FFT Analysis
                                                                                                                                                • 1A722 Frequency Resolution of the Zoom FFT VIs
                                                                                                                                                • 1A723 Zoom Measurement
                                                                                                                                                • 1A724 Zoom Settings
                                                                                                                                                • 1A725 Subset Analysis
                                                                                                                                                    • 1A8 Transient Analysis
                                                                                                                                                      • 1A81 Transient Analysis with the Sound and Vibration Toolkit
                                                                                                                                                      • 1A82 Performing an STFT vs Time
                                                                                                                                                        • 1A821 Selecting the FFT Block Size
                                                                                                                                                        • 1A822 Overlapping
                                                                                                                                                        • 1A823 Using the SVT STFT vs Time VI
                                                                                                                                                          • 1A83 Performing an STFT vs Rotational Speed
                                                                                                                                                            • 1A831 Converting the Pulse Train to Rotational Speed
                                                                                                                                                            • 1A832 STFT vs RPM
                                                                                                                                                              • 1A84 Measuring a Shock Response Spectrum
                                                                                                                                                                • 1A9 Waterfall Display
                                                                                                                                                                  • 1A91 Using the Display VIs
                                                                                                                                                                    • 1A911 Initializing the Display
                                                                                                                                                                    • 1A912 Sending Data to the Display
                                                                                                                                                                    • 1A913 Waterfall Display for Frequency Analysis
                                                                                                                                                                    • 1A914 Waterfall Display for Transient Analysis
                                                                                                                                                                    • 1A915 Waterfall Display for Octave Spectra
                                                                                                                                                                        • 1A10 Swept-Sine Measurements
                                                                                                                                                                          • 1A101 Swept-Sine Overview
                                                                                                                                                                          • 1A102 Choosing Swept-Sine vs FFT Measurements
                                                                                                                                                                          • 1A103 Taking a Swept-Sine Measurement
                                                                                                                                                                          • 1A104 Swept-Sine Measurement Example
                                                                                                                                                                              • Bibliography
                                                                                                                                                                              • Related Titles
                                                                                                                                                                                  • 53191ch2
                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                    • Chapter 2 Signal Conditioning and Modification
                                                                                                                                                                                      • Summary
                                                                                                                                                                                      • 21 Introduction
                                                                                                                                                                                      • 22 Amplifiers
                                                                                                                                                                                        • 221 Operational Amplifier
                                                                                                                                                                                        • 222 Use of Feedback in Opamp
                                                                                                                                                                                        • 223 Voltage Current and Power Amplifiers
                                                                                                                                                                                          • 2231 Charge Amplifiers
                                                                                                                                                                                            • 224 Instrumentation Amplifiers
                                                                                                                                                                                              • 2241 Differential Amplifier
                                                                                                                                                                                              • 2242 Common Mode
                                                                                                                                                                                                • 225 Amplifier Performance Ratings
                                                                                                                                                                                                  • 2251 Common-Mode Rejection Ratio
                                                                                                                                                                                                    • 226 Component Interconnection
                                                                                                                                                                                                      • 2261 Impedance Characteristics
                                                                                                                                                                                                      • 2262 Cascade Connection of Devices
                                                                                                                                                                                                      • 2263 AC-Coupled Ampliers
                                                                                                                                                                                                          • 23 Analog Filters
                                                                                                                                                                                                            • 231 Passive Filters and Active Filters
                                                                                                                                                                                                              • 2311 Number of Poles
                                                                                                                                                                                                                • 232 Low-Pass Filters
                                                                                                                                                                                                                  • 2321 Low-Pass Butterworth Filter
                                                                                                                                                                                                                    • 233 High-Pass Filters
                                                                                                                                                                                                                    • 234 Band-Pass Filters
                                                                                                                                                                                                                      • 2341 Resonance-Type Band-Pass Filters
                                                                                                                                                                                                                        • 235 Band-Reject Filters
                                                                                                                                                                                                                          • 24 Modulators and Demodulators
                                                                                                                                                                                                                            • 241 Amplitude Modulation
                                                                                                                                                                                                                              • 2411 Modulation Theorem
                                                                                                                                                                                                                              • 2412 Side Frequencies and Side Bands
                                                                                                                                                                                                                                • 242 Application of Amplitude Modulation
                                                                                                                                                                                                                                  • 2421 Fault Detection and Diagnosis
                                                                                                                                                                                                                                    • 243 Demodulation
                                                                                                                                                                                                                                      • 25 Analog ndashDigital Conversion
                                                                                                                                                                                                                                        • 251 Digital-to-Analog Conversion
                                                                                                                                                                                                                                          • 2511 DAC Error Sources
                                                                                                                                                                                                                                            • 252 Analog-to-Digital Conversion
                                                                                                                                                                                                                                            • 253 Analog-to-Digital Converter Performance Characteristics
                                                                                                                                                                                                                                              • 2531 Resolution and Quantization Error
                                                                                                                                                                                                                                              • 2532 Monotonicity Nonlinearity and Offset Error
                                                                                                                                                                                                                                              • 2533 Analog-to-Digital Converter Conversion Rate
                                                                                                                                                                                                                                                • 254 Sample-and-Hold Circuitry
                                                                                                                                                                                                                                                • 255 Digital Filters
                                                                                                                                                                                                                                                  • 2551 Software Implementation and Hardware Implementation
                                                                                                                                                                                                                                                      • 26 Bridge Circuits
                                                                                                                                                                                                                                                        • 261 Wheatstone Bridge
                                                                                                                                                                                                                                                        • 262 Constant-Current Bridge
                                                                                                                                                                                                                                                        • 263 Bridge Amplifiers
                                                                                                                                                                                                                                                          • 2631 Half-Bridge Circuits
                                                                                                                                                                                                                                                            • 264 Impedance Bridges
                                                                                                                                                                                                                                                              • 2641 Owen Bridge
                                                                                                                                                                                                                                                              • 2642 Wien-Bridge Oscillator
                                                                                                                                                                                                                                                                  • 27 Linearizing Devices
                                                                                                                                                                                                                                                                    • 271 Linearization by Software
                                                                                                                                                                                                                                                                    • 272 Linearization by Hardware Logic
                                                                                                                                                                                                                                                                    • 273 Analog Linearizing Circuitry
                                                                                                                                                                                                                                                                    • 274 Offsetting Circuitry
                                                                                                                                                                                                                                                                    • 275 Proportional-Output Circuitry
                                                                                                                                                                                                                                                                      • 2751 Curve-Shaping Circuitry
                                                                                                                                                                                                                                                                          • 28 Miscellaneous Signal Modification Circuitry
                                                                                                                                                                                                                                                                            • 281 Phase Shifters
                                                                                                                                                                                                                                                                            • 282 Voltage-to-Frequency Converter
                                                                                                                                                                                                                                                                            • 283 Frequency-to-Voltage Converter
                                                                                                                                                                                                                                                                            • 284 Voltage-to-Current Converters
                                                                                                                                                                                                                                                                            • 285 Peak-Hold Circuits
                                                                                                                                                                                                                                                                              • 29 Signal Analyzers and Display Devices
                                                                                                                                                                                                                                                                                • 291 Signal Analyzers
                                                                                                                                                                                                                                                                                • 292 Oscilloscopes
                                                                                                                                                                                                                                                                                  • 2921 Triggering
                                                                                                                                                                                                                                                                                  • 2922 Lissajous Patterns
                                                                                                                                                                                                                                                                                  • 2923 Digital Oscilloscopes
                                                                                                                                                                                                                                                                                      • Bibliography
                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                          • 53191ch3
                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                            • Chapter 3 Vibration Testing
                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                              • 31 Introduction
                                                                                                                                                                                                                                                                                              • 32 Representation of a Vibration Environment
                                                                                                                                                                                                                                                                                                • 321 Test Signals
                                                                                                                                                                                                                                                                                                  • 3211 Stochastic vs Deterministic Signals
                                                                                                                                                                                                                                                                                                    • 322 Deterministic Signal Representation
                                                                                                                                                                                                                                                                                                      • 3221 Single-Frequency Signals
                                                                                                                                                                                                                                                                                                      • 3222 Sine Sweep
                                                                                                                                                                                                                                                                                                      • 3223 Sine Dwell
                                                                                                                                                                                                                                                                                                      • 3224 Decaying Sine
                                                                                                                                                                                                                                                                                                      • 3225 Sine Beat
                                                                                                                                                                                                                                                                                                      • 3226 Sine Beat with Pauses
                                                                                                                                                                                                                                                                                                      • 3227 Multifrequency Signals
                                                                                                                                                                                                                                                                                                      • 3228 Actual Excitation Records
                                                                                                                                                                                                                                                                                                      • 3229 Simulated Excitation Signals
                                                                                                                                                                                                                                                                                                        • 323 Stochastic Signal Representation
                                                                                                                                                                                                                                                                                                          • 3231 Ergodic Random Signals
                                                                                                                                                                                                                                                                                                          • 3232 Stationary Random Signals
                                                                                                                                                                                                                                                                                                          • 3233 Independent and Uncorrelated Signals
                                                                                                                                                                                                                                                                                                          • 3234 Transmission of Random Excitations
                                                                                                                                                                                                                                                                                                            • 324 Frequency-Domain Representations
                                                                                                                                                                                                                                                                                                              • 3241 Fourier Spectrum Method
                                                                                                                                                                                                                                                                                                              • 3242 Power Spectral Density Method
                                                                                                                                                                                                                                                                                                                • 325 Response Spectrum
                                                                                                                                                                                                                                                                                                                  • 3251 Displacement Velocity and Acceleration Spectra
                                                                                                                                                                                                                                                                                                                  • 3252 Response-Spectra Plotting Paper
                                                                                                                                                                                                                                                                                                                  • 3253 Zero-Period Acceleration
                                                                                                                                                                                                                                                                                                                  • 3254 Uses of Response Spectra
                                                                                                                                                                                                                                                                                                                    • 326 Comparison of Various Representations
                                                                                                                                                                                                                                                                                                                      • 33 Pretest Procedures
                                                                                                                                                                                                                                                                                                                        • 331 Purpose of Testing
                                                                                                                                                                                                                                                                                                                        • 332 Service Functions
                                                                                                                                                                                                                                                                                                                          • 3321 Active Equipment
                                                                                                                                                                                                                                                                                                                          • 3322 Passive Equipment
                                                                                                                                                                                                                                                                                                                          • 3323 Functional Testing
                                                                                                                                                                                                                                                                                                                            • 333 Information Acquisition
                                                                                                                                                                                                                                                                                                                              • 3331 Interface Details
                                                                                                                                                                                                                                                                                                                              • 3332 Effect of Neglecting Interface Dynamics
                                                                                                                                                                                                                                                                                                                              • 3333 Effects of Damping
                                                                                                                                                                                                                                                                                                                              • 3334 Effects of Inertia
                                                                                                                                                                                                                                                                                                                              • 3335 Effect of Natural Frequency
                                                                                                                                                                                                                                                                                                                              • 3336 Effect of Excitation Frequency
                                                                                                                                                                                                                                                                                                                              • 3337 Other Effects of Interface
                                                                                                                                                                                                                                                                                                                                • 334 Test-Program Planning
                                                                                                                                                                                                                                                                                                                                  • 3341 Testing of Cabinet-Mounted Equipment
                                                                                                                                                                                                                                                                                                                                    • 335 Pretest Inspection
                                                                                                                                                                                                                                                                                                                                      • 34 Testing Procedures
                                                                                                                                                                                                                                                                                                                                        • 341 Resonance Search
                                                                                                                                                                                                                                                                                                                                        • 342 Methods of Determining Frequency-Response Functions
                                                                                                                                                                                                                                                                                                                                          • 3421 Fourier Transform Method
                                                                                                                                                                                                                                                                                                                                          • 3422 Spectral Density Method
                                                                                                                                                                                                                                                                                                                                          • 3423 Harmonic Excitation Method
                                                                                                                                                                                                                                                                                                                                            • 343 Resonance-Search Test Methods
                                                                                                                                                                                                                                                                                                                                              • 3431 Hammer (Bump) Test and Drop Test
                                                                                                                                                                                                                                                                                                                                              • 3432 Pluck Test
                                                                                                                                                                                                                                                                                                                                              • 3433 Shaker Tests
                                                                                                                                                                                                                                                                                                                                                • 344 Mechanical Aging
                                                                                                                                                                                                                                                                                                                                                  • 3441 Equivalence for Mechanical Aging
                                                                                                                                                                                                                                                                                                                                                  • 3442 Excitation-Intensity Equivalence
                                                                                                                                                                                                                                                                                                                                                  • 3443 Dynamic-Excitation Equivalence
                                                                                                                                                                                                                                                                                                                                                  • 3444 Cumulative Damage Theory
                                                                                                                                                                                                                                                                                                                                                    • 345 Test-Response Spectrum Generation
                                                                                                                                                                                                                                                                                                                                                    • 346 Instrument Calibration
                                                                                                                                                                                                                                                                                                                                                    • 347 Test-Object Mounting
                                                                                                                                                                                                                                                                                                                                                    • 348 Test-Input Considerations
                                                                                                                                                                                                                                                                                                                                                      • 3481 Test Nomenclature
                                                                                                                                                                                                                                                                                                                                                      • 3482 Testing with Uncorrelated Excitations
                                                                                                                                                                                                                                                                                                                                                      • 3483 Symmetrical Rectilinear Testing
                                                                                                                                                                                                                                                                                                                                                      • 3484 Geometry vs Dynamics
                                                                                                                                                                                                                                                                                                                                                      • 3485 Some Limitations
                                                                                                                                                                                                                                                                                                                                                      • 3486 Testing Black Boxes
                                                                                                                                                                                                                                                                                                                                                      • 3487 Phasing of Excitations
                                                                                                                                                                                                                                                                                                                                                      • 3488 Testing a Gray or White Box
                                                                                                                                                                                                                                                                                                                                                      • 3489 Overtesting in Multitest Sequences
                                                                                                                                                                                                                                                                                                                                                          • 35 Some Practical Information
                                                                                                                                                                                                                                                                                                                                                            • 351 Random Vibration Test Example
                                                                                                                                                                                                                                                                                                                                                            • 352 Vibration Shakers and Control Systems
                                                                                                                                                                                                                                                                                                                                                              • Bibliography
                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                  • 53191ch4
                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                    • Chapter 4 Experimental Modal Analysis
                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                      • 41 Introduction
                                                                                                                                                                                                                                                                                                                                                                      • 42 Frequency-Domain Formulation
                                                                                                                                                                                                                                                                                                                                                                        • 421 Transfer-Function Matrix
                                                                                                                                                                                                                                                                                                                                                                        • 422 Principle of Reciprocity
                                                                                                                                                                                                                                                                                                                                                                          • 43 Experimental Model Development
                                                                                                                                                                                                                                                                                                                                                                            • 431 Extraction of the Time-Domain Model
                                                                                                                                                                                                                                                                                                                                                                              • 44 Curve Fitting of Transfer Functions
                                                                                                                                                                                                                                                                                                                                                                                • 441 Problem Identification
                                                                                                                                                                                                                                                                                                                                                                                • 442 Single- and Multi-Degree-of-Freedom Techniques
                                                                                                                                                                                                                                                                                                                                                                                • 443 Single-Degree-of-Freedom Parameter Extraction in the Frequency Domain
                                                                                                                                                                                                                                                                                                                                                                                  • 4431 Circle-Fit Method
                                                                                                                                                                                                                                                                                                                                                                                    • Case of Viscous Damping
                                                                                                                                                                                                                                                                                                                                                                                    • Case of Hysteretic Damping
                                                                                                                                                                                                                                                                                                                                                                                      • 4432 Peak-Picking Method
                                                                                                                                                                                                                                                                                                                                                                                        • 444 Multi-Degree of Freedom Curve Fitting
                                                                                                                                                                                                                                                                                                                                                                                          • 4441 Formulation of the Method
                                                                                                                                                                                                                                                                                                                                                                                            • 445 A Comment on Static Modes and Rigid-Body Modes
                                                                                                                                                                                                                                                                                                                                                                                            • 446 Residue Extraction
                                                                                                                                                                                                                                                                                                                                                                                              • 45 Laboratory Experiments
                                                                                                                                                                                                                                                                                                                                                                                                • 451 Lumped-Parameter System
                                                                                                                                                                                                                                                                                                                                                                                                  • 4511 Frequency-Domain Test
                                                                                                                                                                                                                                                                                                                                                                                                  • 4512 Time-Domain Tests
                                                                                                                                                                                                                                                                                                                                                                                                    • 452 Distributed-Parameter System
                                                                                                                                                                                                                                                                                                                                                                                                      • 46 Commercial EMA Systems
                                                                                                                                                                                                                                                                                                                                                                                                        • 461 System Configuration
                                                                                                                                                                                                                                                                                                                                                                                                          • 4611 FFT Analysis Options
                                                                                                                                                                                                                                                                                                                                                                                                          • 4612 Modal Analysis Components
                                                                                                                                                                                                                                                                                                                                                                                                              • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                  • 53191ch5
                                                                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                    • Chapter 5 Mechanical Shock
                                                                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                      • 51 Definitions
                                                                                                                                                                                                                                                                                                                                                                                                                        • 511 Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 512 Simple (or Perfect) Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 513 Half-Sine Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 514 Versed-Sine (or Haversine) Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 515 Terminal Peak Sawtooth Shock or Final Peak Sawtooth Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 516 Rectangular Shock
                                                                                                                                                                                                                                                                                                                                                                                                                          • 5161 Trapezoidal Shock
                                                                                                                                                                                                                                                                                                                                                                                                                              • 52 Description in the Time Domain
                                                                                                                                                                                                                                                                                                                                                                                                                              • 53 Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                • 531 Need
                                                                                                                                                                                                                                                                                                                                                                                                                                • 532 Shock Response Spectrum Definition
                                                                                                                                                                                                                                                                                                                                                                                                                                • 533 Response of a Linear One-Degree-of-Freedom System
                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5331 Shock Defined by a Force
                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5332 Shock Defined by an Acceleration
                                                                                                                                                                                                                                                                                                                                                                                                                                    • 534 Definitions
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5341 Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5342 Absolute Acceleration Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5343 Relative Displacement Shock Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5344 Primary Positive Shock Response Spectrum or Initial Positive Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5345 Primary (or Initial) Negative Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5346 Secondary (or Residual) Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5347 Positive (or Maximum Positive) Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5348 Negative (or Maximum Negative) Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5349 Maximax Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53410 Choice of Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                        • 535 Standardized Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5351 Definition
                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5352 Standardized Shock Response Spectra of Simple Shocks
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53521 Half-Sine Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53522 Versed Sine Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53523 Terminal Peak Sawtooth Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53524 Rectangular Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53525 Trapezoidal Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 536 Choice of Damping
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 537 Shock Response Spectra Domains
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 538 Algorithms for Calculation of the Shock Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 539 Choice of the Digitization Frequency of the Signal
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5310 Use of Shock Response Spectra for the Study of Systems with Several Degrees of Freedom
                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 54 Pyroshocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 55 Use of Shock Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 551 Severity Comparison of Several Shocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 552 Test Specification Development from Real Environment Data
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5521 Synthesis of Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5522 Nature of the Specification
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5523 Choice of Shape
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5524 Amplitude
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5525 Duration
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5526 Difficulties
                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 56 Standards
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 561 Types of Standards
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 562 Installation Conditions of Test Item
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 563 Uncertainty Factor
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 564 Bump Test
                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 57 Damage Boundary Curve
                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 571 Definition
                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 572 Analysis of Test Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 58 Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 581 Main Types
                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 582 Impact Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5821 Universal Shock-Test Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 58211 Impact Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 58212 Impulse Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 583 Shock Simulators (Programmers)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5831 Half-Sine Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58311 Shock Duration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58312 Impact Velocity
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58313 Maximum Deformation of the Shock Simulator (Programmer)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58314 Shock Amplitude
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58315 Characteristics of the Target
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5832 Terminal Peak Sawtooth Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5833 Rectangular Pulse ndash Trapezoidal Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5834 Universal Shock Simulator (Programmer)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 58341 Generating a Half-Sine Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 58342 Generating a Terminal Peak Sawtooth Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 58343 Trapezoidal Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 584 Limitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5841 Limitations of the Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5842 Limitations of Shock Simulators
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 585 Pneumatic Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 586 High Impact Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5861 Lightweight High Impact Shock Machine
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5862 Medium Weight High Impact Shock Machine
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 587 Specific Test Facilities
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 59 Generation of Shock Using Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 591 Principle Behind the Generation of a Simple Shape Signal versus Time
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 592 Main Advantages
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 593 Pre- and Postshocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5931 Requirements
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5932 Solutions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 59321 Optimized Pre- and Postpulses
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5933 Incidence on the Shock Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 594 Limitations of Electrodynamic Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5941 Mechanical Limitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 59411 Abacuses
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5942 Electronic Limitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 595 The Use of Electrohydraulic Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 510 Control by a Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 5101 Principle
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 5102 Principal Shapes of Elementary Signals
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 51021 Decaying Sinusoid
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 51022 ZERD Function
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 51023 WAVSIN Waveform
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 5103 Comparison of WAVSIN SHOC Waveforms and Decaying Sinusoid
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 5104 Criticism of Control by a Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 511 Pyrotechnic Shock Simulation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5111 Simulation Using Pyrotechnic Facilities
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5112 Simulation Using Metal-to-Metal Impact
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5113 Simulation Using Electrodynamic Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5114 Simulation Using Conventional Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53191ch6
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Chapter 6 Machine Condition Monitoring and Fault Diagnostics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 61 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 62 Machinery Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 621 Causes of Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 622 Types of Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 623 Frequency of Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 63 Basic Maintenance Strategies
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 631 Run-to-Failure (Breakdown) Maintenance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 632 Scheduled (Preventative) Maintenance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 633 Condition-Based (Predictive Proactive Reliability Centered On-Condition) Maintenance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 64 Factors Which Influence Maintenance Strategy
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 65 Machine Condition Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 651 Periodic Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 652 Continuous Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 66 Transducer Selection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 661 Noncontact Displacement Transducers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 662 Velocity Transducers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 663 Acceleration Transducers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 67 Transducer Location
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 68 Recording and Analysis Instrumentation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 681 Vibration Meters
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 682 Data Collectors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 683 Frequency-Domain Analyzers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 684 Time-Domain Instruments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 685 Tracking Analyzers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 69 Display Formats and Analysis Tools
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 691 Time Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6911 Time-Waveform Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6912 Time-Waveform Indices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6913 Time-Synchronous Averaging
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6914 Negative Averaging
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6915 Orbits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6916 Probability Density Functions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6917 Probability Density Moments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 692 Frequency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6921 Band-Pass Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6922 Shock Pulse (Spike Energy)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6923 Enveloped Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6924 Signature Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6925 Cascades (Waterfall Plots)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6926 Masks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6927 Frequency-Domain Indices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 693 Modal Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 694 Quefrency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 610 Fault Detection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 6101 Standards
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61011 Standards Based on Machinery Type
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61012 Standards Based on Vibration Severity
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 6102 Acceptance Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 61021 Statistical Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 6103 Frequency-Domain Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61031 Limited Band Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61032 Constant Bandwidth Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61033 Constant Percentage Bandwidth Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 611 Fault Diagnostics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 6111 Forcing Functions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61111 Unbalance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61112 Misalignment
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61113 Mechanical Looseness
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61114 Soft Foot
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61115 Rubs
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61116 Resonances
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61117 Oil Whirl
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61118 Oil Whip
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61119 Structural Vibrations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 611110 Foundation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 6112 Specific Machine Components
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 61121 Damaged or Worn Rolling-Element Bearings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 61122 Damaged or Worn Gears
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 6113 Specific Machine Types
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61131 Pumps
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61132 Fans
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61133 Electric Motors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61134 Steam and Gas Turbines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61135 Compressors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61136 Reciprocating Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 6114 Advanced Fault Diagnostic Techniques
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 53191ch7
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • Chapter 7 Vibration-Based Tool Condition Monitoring Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 71 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 72 Mechanics of Turning
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 721 General Terms
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 722 Chatter Vibrations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 723 Tool Wear
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7231 Tool Failure Mechanisms
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7232 Tool Failure Modes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7233 Tool Wear Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7234 Tool Wear Stages
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 73 Vibration Signal Recording
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 731 Direct and Indirect Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 732 Sensor Requirements for Tool Wear Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 733 Force Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7331 Direct Measurement Dynamometers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7332 Indirect Force Sensors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7333 Piezoelectric Strain Sensors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7334 Resistance Strain Gauges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7335 Customized Force Sensors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 734 Acceleration Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 735 Acoustic Emission Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 736 Sensor Comparisons
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 74 Signal Processing for Sensor-Based Tool Condition Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 741 Feature Extraction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7411 Time Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7412 Frequency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7413 Statistical Processing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7414 TimendashFrequency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 742 Feature Selection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 75 Wear ModelDecision-Making for Sensor-Based Tool Condition Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 751 Trending Threshold
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 752 Neural Networks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7521 Unsupervised Networks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7522 Supervised Networks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 753 Fuzzy Logic
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 754 Other Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 76 Conclusion
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53191ch8
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Chapter 8 Fault Diagnosis of Helicopter Gearboxes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 81 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 82 Abnormality Scaling
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 83 The Structure-Based Connectionist Network
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 84 Sensor Location Selection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 841 Coverage Index
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 842 Overlap Index
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 843 Monitoring Effectiveness
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 85 A Case Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 851 Structural and Featural Influences
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 852 Evaluation of Influences
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 853 Fault Detection Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 854 Fault Diagnostic Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 8541 Faulty Subsystem Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 8542 Faulty Component Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 855 Sensor Location Evaluation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 856 Sensor Location Validation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 86 Conclusion
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 53191ch9
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Chapter 9 Vibration Suppression and Monitoring in Precision Motion Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 91 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 92 Mechanical Design to Minimize Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 921 Stability and Static Determinacy of Machine Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 922 Two-Dimensional Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 923 Three-Dimensional Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 93 Adaptive Notch Filter
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 931 Fast Fourier Transform
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 932 Simulation and Experiments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 94 Real-Time Vibration Analyzer
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 941 Learning Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 942 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 943 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 944 Experiments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 9441 Input Variables mdash the Evaluation Criteria
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 94411 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 94412 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 9442 Evaluation Rules
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 94421 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 94422 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 9443 Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 94431 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 94432 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 95 Practical Insights and Case Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 96 Conclusions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 53191ch10
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Chapter 10 Vibration and Shock Problems of Civil Engineering Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 101 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 102 Earthquake-Induced Vibration of Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1021 Seismicity and Ground Motions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1022 Influence of Local Site Conditions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1023 Response of Structures to Ground Motions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1024 Dynamic Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10241 Equations of Motion for Linear Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10242 Equations of Motion for Linear Multiple-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1025 Earthquake Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10251 Elastic Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10252 Smoothed Design Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10253 Ductility-Modified Response Spectrum Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1026 Design Philosophy and the Code Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10261 Performance-Based Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1027 Analysis Options for Earthquake Effects
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10271 Dynamic Time History Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10272 Response Spectrum Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 102721 Response Spectrum Analysis of Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 102722 Response Spectrum Analysis of Multi-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10273 Equivalent Static Analysis (Force-Based Approach)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10274 Displacement-Based Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1028 SoilndashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1029 Active and Passive Control Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 10210 Worked Examples
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 103 Dynamic Effects of Wind Loading on Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1031 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1032 Wind Speed
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1033 Design Structures for Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10331 Types of Wind Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10332 Design Criteria
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10333 Static Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1034 Along and Across-Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10341 Along-Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10342 Across-Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1035 Wind Tunnel Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1036 Comfort Criteria Human Response to Building Motion
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1037 Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1038 Comparison with Earthquake Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 104 Vibrations Due to Fluid ndashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1041 Added Mass and Inertial Coupling
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1042 Wave-Induced Vibration of Structure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 105 Blast Loading and Blast Effects on Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1051 Explosions and Blast Phenomenon
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1052 Explosive Air-Blast Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10521 Blast Wave Scaling Laws
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10522 Prediction of Blast Pressure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1053 Gas Explosion Loading and Effect of Internal Explosions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1054 Structural Response to Blast Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10541 Elastic Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10542 Elasto-Plastic Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1055 Material Behaviors at High Strain Rate
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10551 Dynamic Properties of Concrete under High Strain Rates
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10552 Dynamic Properties of Reinforcing Steel under High Strain Rates
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1056 Failure Modes of Blast-Loaded Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10561 Global Structural Behavior
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10562 Localized Structural Behavior
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10563 PressurendashImpulse ( PndashI ) Diagrams
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1057 Blast WavendashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1058 Effect of Ground Shocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10581 Loads from Air-Induced Ground Shock
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10582 Loads from Direct Ground Shock
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1059 Technical Design Manuals for Blast-Resistant Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 10510 Computer Programs for Blast and Shock Effects
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 106 Impact Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1061 Structural Impact between Two Bodies mdash Hard Impact and Soft Impact
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1062 Example mdash Aircraft Impact
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 107 Floor Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1071 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1072 Types of Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10721 Walking
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10722 Rhythmic Activities
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10723 Mechanical Equipment
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10724 Analysis Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1073 Natural Frequency of Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10731 Computing the Natural Frequency
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10732 Computing Deflection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10733 Damping
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10734 Resonance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1074 Vibration Caused by Walking
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10741 Minimum Natural Frequency
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1075 Design for Rhythmic Excitation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10751 Harmonics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10752 Minimum Natural Frequency
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1076 Example mdash Vibration Analysis of a Reinforced Concrete Floor
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 53191ch11
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Chapter 11 Seismic Base Isolation and Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 111 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1111 From Ductility Design to Base Isolation and Control Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1112 The Importance of Reducing Seismic Input and Response
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 112 Seismic Base Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1121 Historical Development of Base Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1122 Basic Principle
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1123 Issues in Seismic Base Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11231 Performance Criteria
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11232 Type of Structure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11233 Site Characteristics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11234 Retrofit Issues
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11235 Design of Building Services
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11236 Expected Life of Isolator
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1124 Seismic Isolation Devices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11241 Laminated Rubber Bearings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11242 Lead Rubber Bearing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11243 Friction-Based Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11244 Other Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1125 Design of Isolation Devices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11251 High-Damping Rubber Bearing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112511 Stability against Buckling
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112512 Stability against Roll Out
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11252 Lead Rubber Bearings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112521 Design of Lead Plug
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112522 Design of Laminated Rubber Bearing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11253 Design of Friction Pendulum System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1126 Verification of Properties of Isolation Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11261 Tests for Isolation Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 112611 System Characterization Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 112612 Prototype Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 112613 Quality Control Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11262 Uniform Building Code Recommendations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112621 Units Dependent on Loading Rates
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112622 Units Dependent on Bilateral Load
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112623 System Adequacy
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1127 Analysis of Base-Isolated Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11271 Modeling of a Superstructure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11272 Modeling of Isolation System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11273 Static Analysis Procedure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11274 Dynamic Analysis Procedure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 112741 Response Spectrum Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 112742 Time-History Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11275 Software for Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1128 Experimental Methods for Isolated Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1129 Implementation of Seismic Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11291 New Construction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112911 Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112912 Bridges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11292 Seismic Retrofit
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112921 Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112922 Bridges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11293 Other Implementations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 11210 Performance during Past Earthquakes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 112101 Performance of Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 112102 Performance of Bridges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 113 Seismic Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1131 Historical Development of Seismic Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1132 Basic Principles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11321 Passive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11322 Active Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11323 Semiactive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11324 Hybrid Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11325 Categorization of Basic Principles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1133 Important Issues in Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11331 SoilndashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11332 DevicendashStructure Interaction and Time Delay
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11333 Design Guidelines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1134 Vibration-Control Devices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11341 Passive Control Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113411 Metallic Yielding Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113412 Friction Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113413 Viscoelastic Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113414 Viscous Fluid Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113415 Tuned Mass Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11342 Active Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113421 Electromagnetic Actuator
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113422 Hydraulic Actuators
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11343 Semiactive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113431 Variable-Orifice Hydraulic Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113432 Controllable Fluid Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113433 Controllable Friction Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11344 Hybrid Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1135 Control Algorithm
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11351 Active Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11352 Semiactive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113521 Common Control Schemes for Controllable Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113522 Special Control Schemes for Controllable Damper
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1136 Experimental Performance Verification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11361 Shaking Table Tests of a Flexible Structural Model with TMD AMD and ATMD
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11362 Substructure Hybrid Test
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113621 Hybrid Tests Using Hydraulic Actuator
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113622 Hybrid Tests Using Shaking Table
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113623 Hybrid Tests Using Inertia-Force-Driven Loading System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1137 Implementations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11371 Semiactive Control of Full-Scale Structures Using Variable Joint Damper System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113711 Background of Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113712 Test System Set Up
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113713 Control Algorithm
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113714 Test Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11372 Application of Structural Control Technologies to Seismic Retrofit of a Cable-Stayed Bridge
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113721 Background of Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113722 Basic Concept of Seismic Retrofit
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113723 Modal Shape Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113724 Time-History Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113725 Soil ndash Structure Interaction Effect
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113726 Semiactive Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53191ch12
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Chapter 12 Seismic Random Vibration of Long-Span Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 121 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1211 Basic Concepts of Random Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12111 Stationary Random Process
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12112 Nonstationary Random Process
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1212 Three Methods for Structural Seismic Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12121 Response Spectrum Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12122 Time-History Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12123 Random Vibration Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 121231 Davenport Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 121232 Vanmarcke Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 12124 Comparisons of the Three Seismic-Analysis Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 122 Seismic Random-Excitation Fields
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1221 Power Spectral Density of Spatially Varying Ground Acceleration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1222 Several Coherence Models
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12221 FengndashHu Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12222 Harichandran ndashVanmarcke Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12223 LohndashYeh Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12224 OliveirandashHaondashPenzien Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12225 LucondashWong Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12226 QundashWangndashWang Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1223 Generation of Ground Acceleration Power Spectral Density Curves from Acceleration Response Spectrum Curves
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12231 Kaul Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12232 Iteration Scheme
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1224 Seismic Equations of Motion of Long-Span Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1225 Seismic Waves and Their Geometrical Expressions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 123 Pseudoexcitation Method for Structural Random Vibration Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1231 Structures Subjected to Stationary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12311 Single Stationary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12312 Multiple Stationary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1232 Structures Subjected to Nonstationary Random Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12321 Structures Subjected to Uniformly Modulated Evolutionary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 123211 Single Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 123212 Multiple Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12322 Structures Subjected to Nonuniformly Modulated Evolutionary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 123221 Single Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 123222 Multiple Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1233 Precise Integration Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12331 Precise Integration of Exponential Matrices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12332 Particular Solutions and Precise Integration Formulas for Various Forms of Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 123321 Linear Loading Form (HPD-L Form)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 123322 Sinusoidal Loading Form (HPD-S Form)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 123323 Exponentially Decaying Sinusoidal Loading Form (HPD-E Form)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 124 Long-Span Structures Subjected to Stationary Random Ground Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1241 The Solution of Equations of Motion Using the Pseudoexcitation Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1242 Numerical Comparisons with Other Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12421 Song-Hua-Jiang Suspension Bridge
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 124211 All Supports Move Uniformly
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 124212 Wave Passage Effect Is Taken into Account
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 124213 Wave-Passage Effect and Incoherence Effect Are Jointly Taken into Account
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 12422 San Joaquin Concrete Bridge
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 125 Long-Span Structures Subjected to Nonstationary Random Ground Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1251 Modulation Functions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1252 The Formulas for Nonstationary Multiexcitation Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1253 Expected Extreme Values of Nonstationary Random Processes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1254 Numerical Comparisons with the Corresponding Stationary Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 126 Conclusions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 53191ch13
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Chapter 13 Seismic Qualification of Equipment
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 131 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 132 Distribution Qualification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1321 Drive-Signal Generation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1322 Distribution Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1323 Test Procedures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 133 Seismic Qualification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1331 Stages of Seismic Qualification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1332 Test Preliminaries
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1333 Single-Frequency Testing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1334 Multifrequency Testing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1335 Generation of RRS Specifications
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 53191ch14
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Chapter 14 Human Response to Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 141 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 142 Vibration Excitations on Humans
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1421 Excitation Characteristics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 143 Human Response to Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1431 Vibration Perception
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1432 Frequency Weighting Curve
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1433 Iso-Perception Curves
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1434 Detection Threshold Curve
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 144 Regulation of Human Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1441 Acceptable Vibration Levels in Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1442 Whole-Body Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1443 HandndashArm Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
Page 20: Vibration Monitoring, Testing, and Instrumentationpreview.kingborn.net › 646000 › d1a74678d91943e5ba1d5e... · The MEMS Handbook, Second Edition MEMS: Introduction and Fundamentals

Representative segments of typical acceleration RRS curves have slope n as given by

a frac14 k1vn eth114THORN

It should be clear from Equation 113 that the maximum output power is given by

pmax frac14 k2v2n21 eth115THORN

This is an increasing function for n 1=2 and a decreasing function for n 1=2 It follows that the power

rating corresponds to the highest point of contact between the acceleration RRS curve and a line of slope

equal to 12 A similar relationship may be derived if velocity RRS curves (having slopes n2 1) are used

1213 Stroke Rating

From Equation 18 it should be clear that the Fourier spectrum xs of the exciter displacement time

history can be expressed as

xs frac14 2zrarethvTHORN=jv2 eth116THORNAn estimate for stroke rating is

xmax frac14 2zrfrac12larethvTHORNl=v2 max eth117THORNThis is of the form

xmax frac14 kvn22 eth118THORNIt follows that the stroke rating corresponds to the highest point of contact between the acceleration

RRS curve and a line of slope equal to two

Example 11

A test package of overall mass 100 kg is to be

subjected to dynamic excitation represented by the

acceleration RRS (at 5 damping) as shown in

Figure 14 The estimated damping of the test

package is 7 The test package is known to have a

resonance within the frequency range of the

specified test Determine the exciter specifications

for the test

Solution

From the development presented in the previous

section it is clear that the point F (or P) in

Figure 14 corresponds to the force and output

power ratings and the point S corresponds to

the stroke rating The co-ordinates of these

critical points are F P frac14 eth42 Hz 40 gTHORN and S frac14 eth08 Hz 075 gTHORN Equation 110 gives the force

rating as

Fmax frac14 100 pound eth005=007THORN pound 40 pound 981 N frac14 2803 N

Equation 113 gives the power rating as

pmax frac14 2 pound 100 pound eth0052=007THORN pound frac12eth40 pound 981THORN2=42 pound 2p watts frac14 417 W

Equation 117 gives the stroke rating as

xmax frac14 2 pound 005 pound frac12eth075 pound 98THORN=eth08 pound 2pTHORN2 m frac14 3 cm

Acc

eler

atio

n(g

)

Con

stan

t Dis

plac

emen

t

Constant Velo

city

Frequency (Hz)

S

FP

0101

10 10 100

10

10

FIGURE 14 Test excitation specified by an accelera-

tion RRS (5 damping)

Vibration Monitoring Testing and Instrumentation1-8

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copy 2007 by Taylor amp Francis Group LLC

1214 Hydraulic Shakers

A typical hydraulic shaker consists of a piston-cylinder arrangement (also called a ram) a servo-valve a

fluid pump and a driving electric motor Hydraulic fluid (oil) is pressurized (typical operating pressure

4000 psi) and pumped into the cylinder through a servo-valve by means of a pump that is driven by an

electric motor (typical power 150 hp) The flow (typical rate 100 galmin) that enters the cylinder is

controlled (modulated) by the servo-valve which in effect controls the resulting piston (ram) motion

A typical servo-valve consists of a two-stage spool valve which provides a pressure difference and a

controlled (modulated) flow to the piston which sets it in motion

The servo-valve itself is moved by means of a linear torque motor which is driven by the excitation-

input signal (electrical) A primary function of the servo-valve is to provide a stabilizing feedback to the

ram In this respect the servo-valve complements the main control system of the test setup The ram is

coupled to the shaker table by means of a link with some flexibility The cylinder frame is mounted on the

support foundation with swivel joints This allows for some angular and lateral misalignment which

might be caused primarily by test-object dynamics as the table moves

Two-degree-of-freedom (Two-DoF) testing requires two independent sets of actuators and three-DoF

testing requires three independent actuator sets Each independent actuator set can consist of several

actuators operated in parallel using the same pump and the same excitation-input signal to the torque

motors

If the test table is directly supported on the vertical actuators they must withstand the total dead

weight (ie the weight of the test table the test object the mounting fixtures and the instrumentation)

This is requirement is usually prevented by providing a pressurized air cushion in the gap between the

test table and the foundation walls Air should be pressurized so as to balance the total dead weight

exactly (typical required gage pressure 3 psi)

Figure 15(a) shows the basic components of a typical hydraulic shaker The corresponding

operational block diagram is shown in Figure 15(b) It is desirable to locate the actuators in a pit in the

test laboratory so that the test tabletop is flushed with the test laboratory floor under no-load conditions

This minimizes the effort required to place the test object on the test table Otherwise the test object has

to be lifted onto the test table with a forklift Also installation of an aircushion to support the system

dead weight is difficult under these circumstances of elevated mounting

Hydraulic actuators are most suitable for heavy load testing and are widely used in industrial and civil

engineering applications They canbeoperated at very low frequencies (almost direct current [DC]) aswell

as at intermediate frequencies (see Table 11) Large displacements (stroke) are possible at low frequencies

Hydraulic shakers have the advantage of providing high flexibility of operation during the test their

capabilities include variable-force and constant-force testing and wide-band random-input testing The

velocity and acceleration capabilities of hydraulic shakers are moderate Although any general excitation-

input motion (for example sine wave sine beat wide-band random) can be used in hydraulic shakers

faithful reproduction of these signals is virtually impossible at high frequencies because of distortion and

higher-order harmonics introduced by the high noise levels that are common in hydraulic systems This

is only a minor drawback in heavy-duty intermediate-frequency applications Dynamic interactions are

reduced through feedback control

1215 Inertial Shakers

In inertial shakers or ldquomechanical excitersrdquo the force that causes the shaker-table motion is generated by

inertia forces (accelerating masses) Counter-rotating-mass inertial shakers are typical in this category

To understand their principle of operation consider two equal masses rotating in opposite directions at

the same angular speed v and in the same circle of radius r (see Figure 16) This produces a resultant

force equal to 2mv2r cos vt in a fixed direction (the direction of symmetry of the two rotating arms)

Consequently a sinusoidal force with a frequency of v and an amplitude proportional to v2 is generated

This reaction force is applied to the shaker table

Figure 17 shows a sketch of a typical counter-rotating-mass inertial shaker It consists of two identical

rods rotating at the same speed in opposite directions Each rod has a series of slots in which to

Vibration Instrumentation 1-9

53191mdash522007mdash1201mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

place weights In this manner the magnitude of

the eccentric mass can be varied to achieve various

force capabilities The rods are driven by a

variable-speed electric motor through a gear

mechanism that usually provides several speed

ratios A speed ratio is selected depending on the

required test-frequency range The whole system is

symmetrically supported on a carriage that is

directly connected to the test table The test object

is mounted on the test table The preferred

mounting configuration is horizontal so that the

excitation force is applied to the test object in a

horizontal direction In this configuration there

are no variable gravity moments (weight pounddistance to center of gravity) acting on the drive

mechanism Figure 17 shows the vertical con-

figuration In dynamic testing of large structures

the carriage can be mounted directly on the

structure at a location where the excitation force

should be applied By incorporating two pairs of

counter-rotating masses it is possible to generate

test moments as well as test forces

FIGURE 15 A typical hydraulic shaker arrangement (a) schematic diagram (b) operational block diagram

m m

2mw2r cos wt

wtw w

wt

FIGURE 16 Principle of operation of a counter-

rotating-mass inertial shaker

Vibration Monitoring Testing and Instrumentation1-10

53191mdash522007mdash1201mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

Reaction-type shakers driven by inertia are widely used for the prototype testing of civil engineering

structures Their first application dates back to 1935 Inertial shakers are capable of producing

intermediate excitation forces The force generated is limited by the strength of the carriage frame The

frequency range of operation and the maximum velocity and acceleration capabilities are also

intermediate for inertial shakers whereas the maximum displacement capability is typically low A major

limitation of inertial shakers is that their excitation force is exclusively sinusoidal and that the force

amplitude is directly proportional to the square of the excitation frequency As a result complex and

random excitation testing constant-force testing (for example transmissibility tests and constant-force

sine-sweep tests) and flexibility to vary the force amplitude or the displacement amplitude during a test

are not generally feasible with this type of shakers Excitation frequency and amplitude can be varied

during testing however by incorporating a variable-speed drive for the motor The sinusoidal excitation

generated by inertial shakers is virtually undistorted which gives them an advantage over the other types

of shakers when used in sine-dwell and sine-sweep tests Small portable shakers with low-force capability

are available for use in on-site testing

1216 Electromagnetic Shakers

In electromagnetic shakers or ldquoelectrodynamic excitersrdquo the motion is generated using the principle of

operation of an electric motor Specifically the excitation force is produced when a variable excitation

signal (electrical) is passed through a moving coil placed in a magnetic field

The components of a commercial electromagnetic shaker are shown in Figure 18 A steady magnetic

field is generated by a stationary electromagnet that consists of field coils wound on a ferromagnetic base

that is rigidly attached to a protective shell structure The shaker head has a coil wound around it When

the excitation electrical signal is passed through this drive coil the shaker head which is supported on

flexure mounts will be set in motion The shaker head consists of the test table on which the test object

is mounted Shakers with interchangeable heads are available The choice of appropriate shaker head is

based on the geometry and mounting features of the test object The shaker head can be turned to

different angles by means of a swivel joint In this manner different directions of excitation (in biaxial

and triaxial testing) can be obtained

FIGURE 17 Sketch of a counter-rotating-mass inertial shaker

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copy 2007 by Taylor amp Francis Group LLC

122 Dynamics of Electromagnetic Shakers

Consider a single axis electromagnetic shaker (Figure 18) with a test object having a single natural

frequency of importance within the test frequency range The dynamic interactions between the shaker

and the test object give rise to two significant natural frequencies (and correspondingly two significant

resonances) These appear as peaks in the frequency response curve of the test setup Furthermore the

natural frequency (resonance) of the test package alone causes a ldquotroughrdquo or depression (antiresonance)

in the frequency response curve of the overall test setup To explain this characteristic consider the

dynamic model shown in Figure 19 The following mechanical parameters are defined for

Figure 19(a) m k and b are the mass stiffness and equivalent viscous damping constant respectively

of the test package and me ke and be are the corresponding parameters of the exciter (shaker) Also in

the equivalent electrical circuit of the shaker head as shown in Figure 19(b) the following electrical

parameters are defined Re and Le are the resistance and (leakage) inductance and kb is the back

electromotive force (back emf) of the linear motor Assuming that the gravitational forces are supported

FIGURE 18 Schematic sectional view of a typical electromagnetic shaker manufactured by Bruel and Kjaer

Denmark

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by the static deflections of the flexible elements and that the displacements are measured from the static

equilibrium position we have the following system equations

Test object meuroy frac14 2kethy2 yeTHORN2 beth_y2 _yeTHORN eth119THORNShaker head me euroye frac14 fe thorn kethy2 yeTHORN thorn beth_y2 _yeTHORN2 key 2 be _ye eth120THORN

Electrical Lediedt

thorn Reie thorn kb _ye frac14 vethtTHORN eth121THORN

The electromagnetic force fe generated in the shaker head is a result of the interaction of the magnetic

field generated by the current ie with coil of the moving shaker head and the constant magnetic field

(stator) in which the head coil is located Here we have

fe frac14 kbie eth122THORNNote that v(t) is the voltage signal that is applied by the amplifier to the shaker coil ye is the displacement

of the shaker head and y is the displacement response of the test package

It is assumed that kb has consistent electrical and mechanical units (Vmsec and NA) Usually

the electrical time constant of the shaker is quite small compared with the primarily mechanical

time constants of the shaker and the test package In such cases the Ledie=dt term in Equation 121 may

be neglected Consequently the equations from Equation 119 through Equation 122 may be

expressed in the Laplace (frequency) domain with the Laplace variable s taking the place of the derivative

d=dt as

ethms2 thorn bsthorn kTHORNy frac14 ethbsthorn kTHORNye eth123THORN

FIGURE 19 Dynamic models of an electromagnetic shaker and a flexible test package (a) mechanical model

(b) electrical model

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frac12mes2 thorn ethbthorn beTHORNsthorn ethkthorn keTHORN ye frac14 ethbsthorn kTHORNy thorn kb

Rev2

k2bs

Reye eth124THORN

It follows that the transfer function of the shaker head motion with respect to the excitation voltage is

given by

yevfrac14 kb

Re

DethsTHORNDdethsTHORN eth125THORN

where DethsTHORN is the characteristic function of the primary dynamics of the test object

DethsTHORN frac14 ms2 thorn bsthorn k eth126THORN

and DdethsTHORN is the characteristic function of the primary dynamic interactions between the shaker and thetest object

DcethsTHORN frac14 mmes4 thorn frac12methbe thorn bthorn boTHORN thornmeb s

3 thorn frac12methke thorn kTHORN thornmekthorn bethbe thorn boTHORN s2thorn frac12bke thorn ethbe thorn boTHORNk sthorn kke

eth127THORN

where

bo frac14 k2bRe

eth128THORN

It is clear that under low damping conditions DdethsTHORN will produce two resonances as it is fourth order in sand similarly DethsTHORN will produce one antiresonance (trough) corresponding to the resonance of the testobject Note that in the frequency domain s frac14 jv and hence the frequency response function given by

Equation 125 is in fact

yevfrac14 kb

Rb

DethjvTHORNDdethjvTHORN eth129THORN

The magnitude of this frequency response function for a typical test system is sketched in Figure 110

Note that this curve is for the ldquoopen-looprdquo case where there is no feedback from the shaker controller

In practice the shaker controller will be able

to compensate for the resonances and anti-

resonances to some degree depending on its

effectiveness

The main advantages of electromagnetic

shakers are their high frequency range of

operation their high degree of operating flexi-

bility and the high level of accuracy of the

generated shaker motion Faithful reproduction

of complex excitations is possible because of the

advanced electronics and control systems used in

this type of shakers Electromagnetic shakers are

not suitable for heavy-duty applications (large test

objects) however High test-input accelerations

are possible at high frequencies when electromag-

netic shakers are used but their displacement and

velocity capabilities are limited to low or

intermediate values (see Table 11)

100

10

1 10 100Excitation Frequency (Hz)

Antiresonance

Resonance

Shak

erD

ispl

acem

entM

agni

tude

Resonance

1000

FIGURE 110 Frequency response curve of a typical

electromagnetic shaker with a test object

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1221 Transient Exciters

Other varieties of exciters are commonly used in

transient-type vibration testing In these tests

either an impulsive force or an initial excitation is

applied to the test object and the resulting

response is monitored The excitations and the

responses are ldquotransientrdquo in this case Hammer

test drop tests and pluck tests fall into this

category For example a hammer test may be

conducted by hitting the object with an instru-

mented hammer and then measuring the response

of the object The hammer has a force sensor at its

tip as sketched in Figure 111 A piezoelectric or

strain-gage type force sensor may be used More

sophisticated hammers have impedance heads in

place of force sensors An impedance head

measures force and acceleration simultaneously

The results of a hammer test will depend on many

factors for example the dynamics of the hammer

body how firmly the hammer is held during the

impact how quickly the impact is applied and

whether there are multiple impacts

13 Control System

The two primary functions of the shaker control system in vibration testing are (1) to guarantee that the

specified excitation is applied to the test object and (2) to ensure that the dynamic stability (motion

constraints) of the test setup is preserved An operational block diagram illustrating these control

functions is given in Figure 112 The reference input to the control system represents the desired

excitation force that should be applied to the test object In the absence of any control however the force

reaching the test object will be distorted primarily because of (1) dynamic interactions and

nonlinearities of the shaker the test table the mounting fixtures the auxiliary instruments and the test

object itself (2) noise and errors in the signal generator amplifiers filters and other equipment and (3)

external loads and disturbances acting on the test object and other components (for example external

restraints aerodynamic forces friction) To compensate for these distorting factors response

measurements (displacements velocities acceleration and so on) are made at various locations in the

test setup and are used to control the system dynamics In particular the responses of the shaker the test

table and the test object are measured These responses are used to compare the actual excitation felt by

FIGURE 111 An instrumented hammer used in bump

tests or hammer tests

ExcitationInput

(Reference)

Feedback Paths

DriveSignal

ShakerResponse

TestTable

TestObject

Test ObjectResponse

Test TableResponseExciter

(Shaker)(Ram)

Controllerand

Amplifier

FIGURE 112 Operational block diagram illustrating a general shaker control system

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the test object at the shaker interface with the desired (specified) input The drive signal to the shaker is

modified depending on the error that is present

Two types of control are commonly employed in shaker apparatus simple manual control and

complex automatic control Manual control normally consists of simple open-loop trial-and-error

methods of manual adjustments (or calibration) of the control equipment to obtain a desired dynamic

response The actual response is usually monitored (on an oscilloscope or frequency analyzer screen for

example) during manual-control operations The pretest adjustments in manual control can be very

time-consuming as a result the test object might be subjected to overtesting which could produce

cumulative damage is undesirable and could defeat the test purpose Furthermore the calibration

procedure for the experimental setup must be repeated for each new test object

The disadvantages ofmanual control suggest that automatic control is desirable in complex test schemes

in which high accuracy of testing is desired The first step of automatic control involves automatic

measurement of the system response using control sensors and transducers The measurement is then fed

back into the control system which instantaneously determines the best drive signal to actuate the shaker

in order to get the desired excitation This may be done by either analog or digital methods

Primitive control systems require an accurate mathematical description of the test object This

dependency of the control system on the knowledge of test-object dynamics is clearly undesirable

Performance of a good control system should not be considerably affected by the dynamic interactions

and nonlinearities of the test object or by the nature of the excitation Proper selection of feedback signals

and control-system components can reduce such effects and will make the system robust

In the response-spectrum method of vibration testing it is customary to use displacement control at

low frequencies velocity control at intermediate frequency and acceleration control at high frequencies

This necessitates feedback of displacement velocity and acceleration responses Generally however the

most important feedback is the velocity feedback In sine-sweep tests the shaker velocity must change

steadily over the frequency band of interest In particular the velocity control must be precise near the

resonances of the test object Velocity (speed) feedback has a stabilizing effect on the dynamics which is

desirable This effect is particularly useful in ensuring stability in motion when testing is done near

resonances of lightly damped test objects On the contrary displacement (position) feedback can have a

destabilizing effect on some systems particularly when high feedback gains are used

The controller usually consists of various instruments equipment and computation hardware and

software Often the functions of the data-acquisition and processing system overlap with those of the

controller to some extent As an example consider the digital-controller of vibration testing apparatus

First the responses are measured through sensors (and transducers) filtered and amplified

(conditioned) These data channels may be passed through a multiplexer whose purpose is to select

one data channel at a time for processing Most modern data acquisition hardware does not need a

separate multiplexer to handle multiple signals The analog data are converted into digital data using

analog-to-digital converters (ADCs) The resulting sampled data are stored on a disk or as a block data in

the computer memory The reference input signal (typically a signal recorded on an FM tape) is also

sampled (if it is not already in the digital form) using an ADC and fed into the computer Digital

processing is done on the reference signal and the response data with the objective of computing the

command signal to drive the shaker The digital command signal is converted into an analog signal using

a digital-to-analog converter (DAC) and amplified (conditioned) before it is used to drive the exciter

The nature of the control components depends to a large extent on the nature and objectives of the

particular test to be conducted Some of the basic components in a shaker controller are described in

the following subsections

131 Components of a Shaker Controller

1311 Compressor

A compressor circuit is incorporated in automatic excitation control devices to control the excitation-

input level automatically The level of control depends on the feedback signal from a control sensor and

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copy 2007 by Taylor amp Francis Group LLC

the specified (reference) excitation signal Usually the compressor circuit is included in the excitation-

signal generator (for example in a sine generator) The control by this means may be done on the basis of

a single-frequency component (eg the fundamental frequency)

1312 Equalizer (Spectrum Shaper)

Random-signal equalizers are used to shape the spectrum of a random signal in a desired manner In

essence and equalizer consists of a bank of narrow-band filters (for example 80 filters) in parallel over

the operating frequency range By passing the signal through each filter the spectral density (or the mean

square value) of the signal in that narrow frequency band (for example each one-third-octave band) is

determined This is compared with the desired spectral level and automatic adjustment is made in that

filter in case there is an error In some systems response-spectrum analysis is made in place of power

spectral density analysis In that case the equalizer consists of a bank of simple oscillators whose

resonant frequencies are distributed over the operating frequency range of the equalizer The feedback

signal is passed through each oscillator and the peak value of its output is determined This value is

compared with the desired response spectrum value at that frequency If there is an error automatic gain

adjustment is made in the appropriate excitation signal components

Random-noise equalizers are used in conjunction with random signal generators They receive

feedback signals from the control sensors In some digital control systems there are algorithms (software)

that are used to iteratively converge the spectrum of the excitation signal felt by the test object into the

desired spectrum

1313 Tracking Filter

Many vibration tests are based on single-frequency excitations In such cases the control functions

should be performed on the basis of the amplitudes of the fundamental-frequency component of the

signal A tracking filter is simply a frequency-tuned band-pass filter It automatically tunes the center

frequency of its very narrow-band-pass filter to the frequency of a carrier signal Then when a noisy

signal is passed through the tuned filter the output of the filter will be the required fundamental

frequency component in the signal Tracking filters also are useful in obtaining amplitudendashfrequency

plots using an XndashY plotter In such cases the frequency value comes from the signal generator (sweep

oscillator) which produces the carrier signal to the tracking filter The tracking filter then determines the

corresponding amplitude of a signal that is fed into it Most tracking filters have dual channels so that two

signals can be handled (tracked) simultaneously

1314 Excitation Controller (Amplitude Servo-Monitor)

An excitation controller is typically an integral part of the signal generator It can be set so that automatic

sweep between two frequency limits can be performed at a selected sweep rate (linear or logarithmic)

More advanced excitation controllers have the capability of an automatic switch-over between constant-

displacement constant-velocity and constant-acceleration excitation-input control at specified

frequencies over the sweep frequency interval Consequently integrator circuits should be present

within the excitation controller unit to determine velocities and displacements from acceleration signals

Sometimes integration is performed by a separate unit called a vibration meter This unit also offers

the operator the capability of selecting the desired level of each signal (acceleration velocity or

displacement) There is an automatic cut-off level for large displacement values that could result from

noise in acceleration signals A compressor is also a subcomponent of the excitation controller The

complete unit is sometimes known as an amplitude servo-monitor

132 Signal-Generating Equipment

Shakers are force-generating devices that are operated using drive (excitation) signals generated from a

source The excitation-signal source is known as the signal generator Three major types of signal

generators are used in vibration testing applications (1) oscillators (2) random-signal generators and

(3) storage devices In some units oscillators and random-signal generators are combined We shall

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copy 2007 by Taylor amp Francis Group LLC

discuss these two generators separately however because of their difference in function It also should be

noted that almost any digital signal (deterministic or random) can be generated by a digital computer

using a suitable computer program the signal eventually can be passed through a DAC to obtain

the corresponding analog signal These lsquodigitalrsquo signal generators along with analog sources such as

magnetic tape players (FM) are classified into the category of storage devices

The dynamic range of equipment is the ratio of the maximum and minimum output levels (expressed

in decibels) at which it is capable of operating without significant error This is an important specification

for many types of equipment particularly for signal-generating devices The output level of the signal

generator should be set to a value within its dynamic range

1321 Oscillators

Oscillators are essentially single-frequency generators Typically sine signals are generated but other

waveforms (such as rectangular and triangular pulses) are also available in most oscillators Normally

an oscillator has two modes of operation (1) sweeping up and down between two frequency limits and

(2) dwelling at a specified frequency In the sweep operation the sweep rate should be specified This can

be done either on a linear scale (Hzmin) or on a logarithmic scale (octavesmin) In the dwell operation

the frequency points (or intervals) should be specified In either case a desired signal level can be chosen

using the gain-control knob An oscillator that is operated exclusively in the sweep mode is called a sweep

oscillator

The early generation of oscillators employed variable inductor-capacitor types of electronic circuits to

generate signals oscillating at a desired frequency The oscillator is tuned to the required frequency by

varying the capacitance or inductance parameters A DC voltage is applied to energize the capacitor

and to obtain the desired oscillating voltage signal which subsequently is amplified and conditioned

Modern oscillators use operational amplifier circuits along with resistor capacitor and semiconductor

(SC) elements Also common are crystal (quartz) parallel-resonance oscillators used to generate voltage

signals accurately at a fixed frequency The circuit is activated using a DC-voltage source Other

frequencies of interest are obtained by passing this high-frequency signal through a frequency converter

The signal is then conditioned (amplified and filtered) Required shaping (for example rectangular

pulse) is obtained using a shape circuit Finally the required signal level is obtained by passing the

resulting signal through a variable-gain amplifier A block diagram of an oscillator illustrating various

stages in the generation of a periodic signal is given in Figure 113

A typical oscillator offers a choice of several (typically six) linear and logarithmic frequency ranges and

a sizable level of control capability (for example 80 dB) Upper and lower frequency limits in a sweep can

be preset on the front panel to any of the available frequency ranges Sweep-rate settings are continuously

DC Voltage

Oscillator

FrequencySpecification

FrequencyConverter

FilterAmplifier

ShaperPeriodicSignal

FrequencyCounter

Fixed-FrequencySignal

Variable-GainOutput

Amplifier

SignalSpecification

LevelSpecification

FIGURE 113 Block diagram of an oscillator-type signal generator

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copy 2007 by Taylor amp Francis Group LLC

  • 53191fm
    • Vibration Monitoring Testing and Instrumentation
      • Preface
      • Acknowledgments
      • Editor-in-Chief
      • Contributors
      • Contents
      • Related Titles
          • 53191ch1
            • Table of Contents
            • Chapter 1 Vibration Instrumentation
              • Summary
              • 11 Introduction
              • 12 Vibration Exciters
                • 121 Shaker Selection
                  • 1211 Force Rating
                  • 1212 Power Rating
                  • 1213 Stroke Rating
                  • 1214 Hydraulic Shakers
                  • 1215 Inertial Shakers
                  • 1216 Electromagnetic Shakers
                    • 122 Dynamics of Electromagnetic Shakers
                      • 1221 Transient Exciters
                          • 13 Control System
                            • 131 Components of a Shaker Controller
                              • 1311 Compressor
                              • 1312 Equalizer (Spectrum Shaper)
                              • 1313 Tracking Filter
                              • 1314 Excitation Controller (Amplitude Servo-Monitor)
                                • 132 Signal-Generating Equipment
                                  • 1321 Oscillators
                                  • 1322 Random Signal Generators
                                  • 1323 Tape Players
                                  • 1324 Data Processing
                                      • 14 Performance Specification
                                        • 141 Parameters for Performance Specification
                                          • 1411 Time-Domain Specifications
                                          • 1412 Frequency-Domain Specifications
                                            • 142 Linearity
                                            • 143 Instrument Ratings
                                              • 1431 Rating Parameters
                                                • 144 Accuracy and Precision
                                                  • 15 Motion Sensors and Transducers
                                                    • 151 Potentiometer
                                                      • 1511 Potentiometer Resolution
                                                      • 1512 Optical Potentiometer
                                                        • 152 Variable-Inductance Transducers
                                                          • 1521 Mutual-Induction Transducers
                                                          • 1522 Linear-Variable Differential Transformer
                                                          • 1523 Signal Conditioning
                                                            • 153 Mutual-Induction Proximity Sensor
                                                            • 154 Selfinduction Transducers
                                                            • 155 Permanent-Magnet Transducers
                                                            • 156 Alternating Current Permanent-Magnet Tachometer
                                                            • 157 Alternating Current Induction Tachometer
                                                            • 158 Eddy Current Transducers
                                                            • 159 Variable-Capacitance Transducers
                                                              • 1591 Capacitive Displacement Sensors
                                                              • 1592 Capacitive Angular Velocity Sensor
                                                              • 1593 Capacitance Bridge Circuit
                                                                • 1510 Piezoelectric Transducers
                                                                  • 15101 Sensitivity
                                                                  • 15102 Piezoelectric Accelerometer
                                                                  • 15103 Charge Amplifier
                                                                      • 16 Torque Force and Other Sensors
                                                                        • 161 Strain Gage Sensors
                                                                          • 1611 Equations for Strain Gage Measurements
                                                                          • 1612 Bridge Sensitivity
                                                                          • 1613 The Bridge Constant
                                                                          • 1614 The Calibration Constant
                                                                          • 1615 Data Acquisition
                                                                          • 1616 Accuracy Considerations
                                                                          • 1617 Semiconductor Strain Gages
                                                                          • 1618 Force and Torque Sensors
                                                                          • 1619 Strain Gage Torque Sensors
                                                                          • 16110 Deflection Torque Sensors
                                                                          • 16111 Variable-Reluctance Torque Sensor
                                                                          • 16112 Reaction Torque Sensors
                                                                            • 162 Miscellaneous Sensors
                                                                              • 1621 Stroboscope
                                                                              • 1622 Fiber Optic Sensors and Lasers
                                                                              • 1623 Fiber-Optic Gyroscope
                                                                              • 1624 Laser Doppler Interferometer
                                                                              • 1625 Ultrasonic Sensors
                                                                              • 1626 Gyroscopic Sensors
                                                                                  • References
                                                                                  • Appendix 1A Virtual Instrumentation for Data Acquisition Analysis and Presentation
                                                                                    • Summary
                                                                                    • List of Abbreviations
                                                                                    • 1A1 Dynamic Signals
                                                                                      • 1A11 Acquiring and Simulating Dynamic Signals
                                                                                        • 1A111 Aliasing
                                                                                        • 1A112 Time Continuity
                                                                                            • 1A2 Measurement Configuration Considerations
                                                                                              • 1A21 Input Signal Considerations
                                                                                                • 1A211 Input Pseudodifferential and Differential Configuration
                                                                                                • 1A212 Gain
                                                                                                • 1A213 Input Coupling
                                                                                                • 1A214 Integrated Electronic Piezoelectric Excitation
                                                                                                • 1A215 Nyquist Frequency and Bandwidth
                                                                                                • 1A216 Analog-to-Digital Conversion
                                                                                                • 1A217 Antialias Filters
                                                                                                • 1A218 Input Filter Delay
                                                                                                • 1A219 Overload Detection
                                                                                                  • 1A22 Output Signal Considerations
                                                                                                    • 1A221 Output Pseudodifferential and Differential Configuration
                                                                                                    • 1A222 Attenuation
                                                                                                    • 1A223 Digital-to-Analog Conversion
                                                                                                    • 1A224 Anti-imaging and Interpolation Filters
                                                                                                    • 1A225 Output Filter Delay
                                                                                                        • 1A3 Scaling and Calibration
                                                                                                          • 1A31 Scaling to Engineering Units
                                                                                                          • 1A32 Performing System Calibration
                                                                                                            • 1A321 Propagation Delay Calibration
                                                                                                                • 1A4 Limit Testing Analysis
                                                                                                                  • 1A41 Limit Testing Overview
                                                                                                                  • 1A42 Using the SVT Limit Testing VI
                                                                                                                    • 1A5 Integration
                                                                                                                      • 1A51 Introduction to Integration
                                                                                                                      • 1A52 Implementing Integration
                                                                                                                        • 1A521 Challenges when Integrating Vibration Data
                                                                                                                          • 1A53 Time-Domain Integration
                                                                                                                            • 1A531 Single-Shot Acquisition and Integration
                                                                                                                            • 1A532 Continuous Acquisition and Integration
                                                                                                                              • 1A54 Frequency-Domain Integration
                                                                                                                                • 1A6 Vibration-Level Measurements
                                                                                                                                  • 1A61 Measuring the Root Mean Square Level
                                                                                                                                    • 1A611 Single-Shot Buffered Acquisition
                                                                                                                                    • 1A612 Continuous Signal Acquisition
                                                                                                                                      • 1A62 Performing a Running RMS Level Measurement
                                                                                                                                      • 1A63 Computing the Peak Level
                                                                                                                                      • 1A64 Computing the Crest Factor
                                                                                                                                        • 1A7 Frequency Analysis
                                                                                                                                          • 1A71 FFT Fundamentals
                                                                                                                                            • 1A711 Number of Samples
                                                                                                                                            • 1A712 Frequency Resolution
                                                                                                                                            • 1A713 Maximum Resolvable Frequency
                                                                                                                                            • 1A714 Minimum Resolvable Frequency
                                                                                                                                            • 1A715 Number of Spectral Lines
                                                                                                                                            • 1A716 Relationship between Time-Domain and Frequency-Domain Specifications and Parameters
                                                                                                                                              • 1A72 Increasing Frequency Resolution
                                                                                                                                                • 1A721 Zoom FFT Analysis
                                                                                                                                                • 1A722 Frequency Resolution of the Zoom FFT VIs
                                                                                                                                                • 1A723 Zoom Measurement
                                                                                                                                                • 1A724 Zoom Settings
                                                                                                                                                • 1A725 Subset Analysis
                                                                                                                                                    • 1A8 Transient Analysis
                                                                                                                                                      • 1A81 Transient Analysis with the Sound and Vibration Toolkit
                                                                                                                                                      • 1A82 Performing an STFT vs Time
                                                                                                                                                        • 1A821 Selecting the FFT Block Size
                                                                                                                                                        • 1A822 Overlapping
                                                                                                                                                        • 1A823 Using the SVT STFT vs Time VI
                                                                                                                                                          • 1A83 Performing an STFT vs Rotational Speed
                                                                                                                                                            • 1A831 Converting the Pulse Train to Rotational Speed
                                                                                                                                                            • 1A832 STFT vs RPM
                                                                                                                                                              • 1A84 Measuring a Shock Response Spectrum
                                                                                                                                                                • 1A9 Waterfall Display
                                                                                                                                                                  • 1A91 Using the Display VIs
                                                                                                                                                                    • 1A911 Initializing the Display
                                                                                                                                                                    • 1A912 Sending Data to the Display
                                                                                                                                                                    • 1A913 Waterfall Display for Frequency Analysis
                                                                                                                                                                    • 1A914 Waterfall Display for Transient Analysis
                                                                                                                                                                    • 1A915 Waterfall Display for Octave Spectra
                                                                                                                                                                        • 1A10 Swept-Sine Measurements
                                                                                                                                                                          • 1A101 Swept-Sine Overview
                                                                                                                                                                          • 1A102 Choosing Swept-Sine vs FFT Measurements
                                                                                                                                                                          • 1A103 Taking a Swept-Sine Measurement
                                                                                                                                                                          • 1A104 Swept-Sine Measurement Example
                                                                                                                                                                              • Bibliography
                                                                                                                                                                              • Related Titles
                                                                                                                                                                                  • 53191ch2
                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                    • Chapter 2 Signal Conditioning and Modification
                                                                                                                                                                                      • Summary
                                                                                                                                                                                      • 21 Introduction
                                                                                                                                                                                      • 22 Amplifiers
                                                                                                                                                                                        • 221 Operational Amplifier
                                                                                                                                                                                        • 222 Use of Feedback in Opamp
                                                                                                                                                                                        • 223 Voltage Current and Power Amplifiers
                                                                                                                                                                                          • 2231 Charge Amplifiers
                                                                                                                                                                                            • 224 Instrumentation Amplifiers
                                                                                                                                                                                              • 2241 Differential Amplifier
                                                                                                                                                                                              • 2242 Common Mode
                                                                                                                                                                                                • 225 Amplifier Performance Ratings
                                                                                                                                                                                                  • 2251 Common-Mode Rejection Ratio
                                                                                                                                                                                                    • 226 Component Interconnection
                                                                                                                                                                                                      • 2261 Impedance Characteristics
                                                                                                                                                                                                      • 2262 Cascade Connection of Devices
                                                                                                                                                                                                      • 2263 AC-Coupled Ampliers
                                                                                                                                                                                                          • 23 Analog Filters
                                                                                                                                                                                                            • 231 Passive Filters and Active Filters
                                                                                                                                                                                                              • 2311 Number of Poles
                                                                                                                                                                                                                • 232 Low-Pass Filters
                                                                                                                                                                                                                  • 2321 Low-Pass Butterworth Filter
                                                                                                                                                                                                                    • 233 High-Pass Filters
                                                                                                                                                                                                                    • 234 Band-Pass Filters
                                                                                                                                                                                                                      • 2341 Resonance-Type Band-Pass Filters
                                                                                                                                                                                                                        • 235 Band-Reject Filters
                                                                                                                                                                                                                          • 24 Modulators and Demodulators
                                                                                                                                                                                                                            • 241 Amplitude Modulation
                                                                                                                                                                                                                              • 2411 Modulation Theorem
                                                                                                                                                                                                                              • 2412 Side Frequencies and Side Bands
                                                                                                                                                                                                                                • 242 Application of Amplitude Modulation
                                                                                                                                                                                                                                  • 2421 Fault Detection and Diagnosis
                                                                                                                                                                                                                                    • 243 Demodulation
                                                                                                                                                                                                                                      • 25 Analog ndashDigital Conversion
                                                                                                                                                                                                                                        • 251 Digital-to-Analog Conversion
                                                                                                                                                                                                                                          • 2511 DAC Error Sources
                                                                                                                                                                                                                                            • 252 Analog-to-Digital Conversion
                                                                                                                                                                                                                                            • 253 Analog-to-Digital Converter Performance Characteristics
                                                                                                                                                                                                                                              • 2531 Resolution and Quantization Error
                                                                                                                                                                                                                                              • 2532 Monotonicity Nonlinearity and Offset Error
                                                                                                                                                                                                                                              • 2533 Analog-to-Digital Converter Conversion Rate
                                                                                                                                                                                                                                                • 254 Sample-and-Hold Circuitry
                                                                                                                                                                                                                                                • 255 Digital Filters
                                                                                                                                                                                                                                                  • 2551 Software Implementation and Hardware Implementation
                                                                                                                                                                                                                                                      • 26 Bridge Circuits
                                                                                                                                                                                                                                                        • 261 Wheatstone Bridge
                                                                                                                                                                                                                                                        • 262 Constant-Current Bridge
                                                                                                                                                                                                                                                        • 263 Bridge Amplifiers
                                                                                                                                                                                                                                                          • 2631 Half-Bridge Circuits
                                                                                                                                                                                                                                                            • 264 Impedance Bridges
                                                                                                                                                                                                                                                              • 2641 Owen Bridge
                                                                                                                                                                                                                                                              • 2642 Wien-Bridge Oscillator
                                                                                                                                                                                                                                                                  • 27 Linearizing Devices
                                                                                                                                                                                                                                                                    • 271 Linearization by Software
                                                                                                                                                                                                                                                                    • 272 Linearization by Hardware Logic
                                                                                                                                                                                                                                                                    • 273 Analog Linearizing Circuitry
                                                                                                                                                                                                                                                                    • 274 Offsetting Circuitry
                                                                                                                                                                                                                                                                    • 275 Proportional-Output Circuitry
                                                                                                                                                                                                                                                                      • 2751 Curve-Shaping Circuitry
                                                                                                                                                                                                                                                                          • 28 Miscellaneous Signal Modification Circuitry
                                                                                                                                                                                                                                                                            • 281 Phase Shifters
                                                                                                                                                                                                                                                                            • 282 Voltage-to-Frequency Converter
                                                                                                                                                                                                                                                                            • 283 Frequency-to-Voltage Converter
                                                                                                                                                                                                                                                                            • 284 Voltage-to-Current Converters
                                                                                                                                                                                                                                                                            • 285 Peak-Hold Circuits
                                                                                                                                                                                                                                                                              • 29 Signal Analyzers and Display Devices
                                                                                                                                                                                                                                                                                • 291 Signal Analyzers
                                                                                                                                                                                                                                                                                • 292 Oscilloscopes
                                                                                                                                                                                                                                                                                  • 2921 Triggering
                                                                                                                                                                                                                                                                                  • 2922 Lissajous Patterns
                                                                                                                                                                                                                                                                                  • 2923 Digital Oscilloscopes
                                                                                                                                                                                                                                                                                      • Bibliography
                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                          • 53191ch3
                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                            • Chapter 3 Vibration Testing
                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                              • 31 Introduction
                                                                                                                                                                                                                                                                                              • 32 Representation of a Vibration Environment
                                                                                                                                                                                                                                                                                                • 321 Test Signals
                                                                                                                                                                                                                                                                                                  • 3211 Stochastic vs Deterministic Signals
                                                                                                                                                                                                                                                                                                    • 322 Deterministic Signal Representation
                                                                                                                                                                                                                                                                                                      • 3221 Single-Frequency Signals
                                                                                                                                                                                                                                                                                                      • 3222 Sine Sweep
                                                                                                                                                                                                                                                                                                      • 3223 Sine Dwell
                                                                                                                                                                                                                                                                                                      • 3224 Decaying Sine
                                                                                                                                                                                                                                                                                                      • 3225 Sine Beat
                                                                                                                                                                                                                                                                                                      • 3226 Sine Beat with Pauses
                                                                                                                                                                                                                                                                                                      • 3227 Multifrequency Signals
                                                                                                                                                                                                                                                                                                      • 3228 Actual Excitation Records
                                                                                                                                                                                                                                                                                                      • 3229 Simulated Excitation Signals
                                                                                                                                                                                                                                                                                                        • 323 Stochastic Signal Representation
                                                                                                                                                                                                                                                                                                          • 3231 Ergodic Random Signals
                                                                                                                                                                                                                                                                                                          • 3232 Stationary Random Signals
                                                                                                                                                                                                                                                                                                          • 3233 Independent and Uncorrelated Signals
                                                                                                                                                                                                                                                                                                          • 3234 Transmission of Random Excitations
                                                                                                                                                                                                                                                                                                            • 324 Frequency-Domain Representations
                                                                                                                                                                                                                                                                                                              • 3241 Fourier Spectrum Method
                                                                                                                                                                                                                                                                                                              • 3242 Power Spectral Density Method
                                                                                                                                                                                                                                                                                                                • 325 Response Spectrum
                                                                                                                                                                                                                                                                                                                  • 3251 Displacement Velocity and Acceleration Spectra
                                                                                                                                                                                                                                                                                                                  • 3252 Response-Spectra Plotting Paper
                                                                                                                                                                                                                                                                                                                  • 3253 Zero-Period Acceleration
                                                                                                                                                                                                                                                                                                                  • 3254 Uses of Response Spectra
                                                                                                                                                                                                                                                                                                                    • 326 Comparison of Various Representations
                                                                                                                                                                                                                                                                                                                      • 33 Pretest Procedures
                                                                                                                                                                                                                                                                                                                        • 331 Purpose of Testing
                                                                                                                                                                                                                                                                                                                        • 332 Service Functions
                                                                                                                                                                                                                                                                                                                          • 3321 Active Equipment
                                                                                                                                                                                                                                                                                                                          • 3322 Passive Equipment
                                                                                                                                                                                                                                                                                                                          • 3323 Functional Testing
                                                                                                                                                                                                                                                                                                                            • 333 Information Acquisition
                                                                                                                                                                                                                                                                                                                              • 3331 Interface Details
                                                                                                                                                                                                                                                                                                                              • 3332 Effect of Neglecting Interface Dynamics
                                                                                                                                                                                                                                                                                                                              • 3333 Effects of Damping
                                                                                                                                                                                                                                                                                                                              • 3334 Effects of Inertia
                                                                                                                                                                                                                                                                                                                              • 3335 Effect of Natural Frequency
                                                                                                                                                                                                                                                                                                                              • 3336 Effect of Excitation Frequency
                                                                                                                                                                                                                                                                                                                              • 3337 Other Effects of Interface
                                                                                                                                                                                                                                                                                                                                • 334 Test-Program Planning
                                                                                                                                                                                                                                                                                                                                  • 3341 Testing of Cabinet-Mounted Equipment
                                                                                                                                                                                                                                                                                                                                    • 335 Pretest Inspection
                                                                                                                                                                                                                                                                                                                                      • 34 Testing Procedures
                                                                                                                                                                                                                                                                                                                                        • 341 Resonance Search
                                                                                                                                                                                                                                                                                                                                        • 342 Methods of Determining Frequency-Response Functions
                                                                                                                                                                                                                                                                                                                                          • 3421 Fourier Transform Method
                                                                                                                                                                                                                                                                                                                                          • 3422 Spectral Density Method
                                                                                                                                                                                                                                                                                                                                          • 3423 Harmonic Excitation Method
                                                                                                                                                                                                                                                                                                                                            • 343 Resonance-Search Test Methods
                                                                                                                                                                                                                                                                                                                                              • 3431 Hammer (Bump) Test and Drop Test
                                                                                                                                                                                                                                                                                                                                              • 3432 Pluck Test
                                                                                                                                                                                                                                                                                                                                              • 3433 Shaker Tests
                                                                                                                                                                                                                                                                                                                                                • 344 Mechanical Aging
                                                                                                                                                                                                                                                                                                                                                  • 3441 Equivalence for Mechanical Aging
                                                                                                                                                                                                                                                                                                                                                  • 3442 Excitation-Intensity Equivalence
                                                                                                                                                                                                                                                                                                                                                  • 3443 Dynamic-Excitation Equivalence
                                                                                                                                                                                                                                                                                                                                                  • 3444 Cumulative Damage Theory
                                                                                                                                                                                                                                                                                                                                                    • 345 Test-Response Spectrum Generation
                                                                                                                                                                                                                                                                                                                                                    • 346 Instrument Calibration
                                                                                                                                                                                                                                                                                                                                                    • 347 Test-Object Mounting
                                                                                                                                                                                                                                                                                                                                                    • 348 Test-Input Considerations
                                                                                                                                                                                                                                                                                                                                                      • 3481 Test Nomenclature
                                                                                                                                                                                                                                                                                                                                                      • 3482 Testing with Uncorrelated Excitations
                                                                                                                                                                                                                                                                                                                                                      • 3483 Symmetrical Rectilinear Testing
                                                                                                                                                                                                                                                                                                                                                      • 3484 Geometry vs Dynamics
                                                                                                                                                                                                                                                                                                                                                      • 3485 Some Limitations
                                                                                                                                                                                                                                                                                                                                                      • 3486 Testing Black Boxes
                                                                                                                                                                                                                                                                                                                                                      • 3487 Phasing of Excitations
                                                                                                                                                                                                                                                                                                                                                      • 3488 Testing a Gray or White Box
                                                                                                                                                                                                                                                                                                                                                      • 3489 Overtesting in Multitest Sequences
                                                                                                                                                                                                                                                                                                                                                          • 35 Some Practical Information
                                                                                                                                                                                                                                                                                                                                                            • 351 Random Vibration Test Example
                                                                                                                                                                                                                                                                                                                                                            • 352 Vibration Shakers and Control Systems
                                                                                                                                                                                                                                                                                                                                                              • Bibliography
                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                  • 53191ch4
                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                    • Chapter 4 Experimental Modal Analysis
                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                      • 41 Introduction
                                                                                                                                                                                                                                                                                                                                                                      • 42 Frequency-Domain Formulation
                                                                                                                                                                                                                                                                                                                                                                        • 421 Transfer-Function Matrix
                                                                                                                                                                                                                                                                                                                                                                        • 422 Principle of Reciprocity
                                                                                                                                                                                                                                                                                                                                                                          • 43 Experimental Model Development
                                                                                                                                                                                                                                                                                                                                                                            • 431 Extraction of the Time-Domain Model
                                                                                                                                                                                                                                                                                                                                                                              • 44 Curve Fitting of Transfer Functions
                                                                                                                                                                                                                                                                                                                                                                                • 441 Problem Identification
                                                                                                                                                                                                                                                                                                                                                                                • 442 Single- and Multi-Degree-of-Freedom Techniques
                                                                                                                                                                                                                                                                                                                                                                                • 443 Single-Degree-of-Freedom Parameter Extraction in the Frequency Domain
                                                                                                                                                                                                                                                                                                                                                                                  • 4431 Circle-Fit Method
                                                                                                                                                                                                                                                                                                                                                                                    • Case of Viscous Damping
                                                                                                                                                                                                                                                                                                                                                                                    • Case of Hysteretic Damping
                                                                                                                                                                                                                                                                                                                                                                                      • 4432 Peak-Picking Method
                                                                                                                                                                                                                                                                                                                                                                                        • 444 Multi-Degree of Freedom Curve Fitting
                                                                                                                                                                                                                                                                                                                                                                                          • 4441 Formulation of the Method
                                                                                                                                                                                                                                                                                                                                                                                            • 445 A Comment on Static Modes and Rigid-Body Modes
                                                                                                                                                                                                                                                                                                                                                                                            • 446 Residue Extraction
                                                                                                                                                                                                                                                                                                                                                                                              • 45 Laboratory Experiments
                                                                                                                                                                                                                                                                                                                                                                                                • 451 Lumped-Parameter System
                                                                                                                                                                                                                                                                                                                                                                                                  • 4511 Frequency-Domain Test
                                                                                                                                                                                                                                                                                                                                                                                                  • 4512 Time-Domain Tests
                                                                                                                                                                                                                                                                                                                                                                                                    • 452 Distributed-Parameter System
                                                                                                                                                                                                                                                                                                                                                                                                      • 46 Commercial EMA Systems
                                                                                                                                                                                                                                                                                                                                                                                                        • 461 System Configuration
                                                                                                                                                                                                                                                                                                                                                                                                          • 4611 FFT Analysis Options
                                                                                                                                                                                                                                                                                                                                                                                                          • 4612 Modal Analysis Components
                                                                                                                                                                                                                                                                                                                                                                                                              • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                  • 53191ch5
                                                                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                    • Chapter 5 Mechanical Shock
                                                                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                      • 51 Definitions
                                                                                                                                                                                                                                                                                                                                                                                                                        • 511 Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 512 Simple (or Perfect) Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 513 Half-Sine Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 514 Versed-Sine (or Haversine) Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 515 Terminal Peak Sawtooth Shock or Final Peak Sawtooth Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 516 Rectangular Shock
                                                                                                                                                                                                                                                                                                                                                                                                                          • 5161 Trapezoidal Shock
                                                                                                                                                                                                                                                                                                                                                                                                                              • 52 Description in the Time Domain
                                                                                                                                                                                                                                                                                                                                                                                                                              • 53 Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                • 531 Need
                                                                                                                                                                                                                                                                                                                                                                                                                                • 532 Shock Response Spectrum Definition
                                                                                                                                                                                                                                                                                                                                                                                                                                • 533 Response of a Linear One-Degree-of-Freedom System
                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5331 Shock Defined by a Force
                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5332 Shock Defined by an Acceleration
                                                                                                                                                                                                                                                                                                                                                                                                                                    • 534 Definitions
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5341 Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5342 Absolute Acceleration Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5343 Relative Displacement Shock Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5344 Primary Positive Shock Response Spectrum or Initial Positive Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5345 Primary (or Initial) Negative Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5346 Secondary (or Residual) Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5347 Positive (or Maximum Positive) Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5348 Negative (or Maximum Negative) Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5349 Maximax Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53410 Choice of Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                        • 535 Standardized Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5351 Definition
                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5352 Standardized Shock Response Spectra of Simple Shocks
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53521 Half-Sine Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53522 Versed Sine Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53523 Terminal Peak Sawtooth Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53524 Rectangular Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53525 Trapezoidal Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 536 Choice of Damping
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 537 Shock Response Spectra Domains
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 538 Algorithms for Calculation of the Shock Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 539 Choice of the Digitization Frequency of the Signal
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5310 Use of Shock Response Spectra for the Study of Systems with Several Degrees of Freedom
                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 54 Pyroshocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 55 Use of Shock Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 551 Severity Comparison of Several Shocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 552 Test Specification Development from Real Environment Data
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5521 Synthesis of Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5522 Nature of the Specification
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5523 Choice of Shape
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5524 Amplitude
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5525 Duration
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5526 Difficulties
                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 56 Standards
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 561 Types of Standards
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 562 Installation Conditions of Test Item
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 563 Uncertainty Factor
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 564 Bump Test
                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 57 Damage Boundary Curve
                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 571 Definition
                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 572 Analysis of Test Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 58 Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 581 Main Types
                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 582 Impact Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5821 Universal Shock-Test Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 58211 Impact Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 58212 Impulse Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 583 Shock Simulators (Programmers)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5831 Half-Sine Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58311 Shock Duration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58312 Impact Velocity
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58313 Maximum Deformation of the Shock Simulator (Programmer)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58314 Shock Amplitude
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58315 Characteristics of the Target
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5832 Terminal Peak Sawtooth Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5833 Rectangular Pulse ndash Trapezoidal Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5834 Universal Shock Simulator (Programmer)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 58341 Generating a Half-Sine Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 58342 Generating a Terminal Peak Sawtooth Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 58343 Trapezoidal Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 584 Limitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5841 Limitations of the Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5842 Limitations of Shock Simulators
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 585 Pneumatic Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 586 High Impact Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5861 Lightweight High Impact Shock Machine
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5862 Medium Weight High Impact Shock Machine
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 587 Specific Test Facilities
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 59 Generation of Shock Using Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 591 Principle Behind the Generation of a Simple Shape Signal versus Time
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 592 Main Advantages
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 593 Pre- and Postshocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5931 Requirements
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5932 Solutions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 59321 Optimized Pre- and Postpulses
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5933 Incidence on the Shock Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 594 Limitations of Electrodynamic Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5941 Mechanical Limitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 59411 Abacuses
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5942 Electronic Limitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 595 The Use of Electrohydraulic Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 510 Control by a Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 5101 Principle
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 5102 Principal Shapes of Elementary Signals
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 51021 Decaying Sinusoid
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 51022 ZERD Function
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 51023 WAVSIN Waveform
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 5103 Comparison of WAVSIN SHOC Waveforms and Decaying Sinusoid
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 5104 Criticism of Control by a Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 511 Pyrotechnic Shock Simulation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5111 Simulation Using Pyrotechnic Facilities
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5112 Simulation Using Metal-to-Metal Impact
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5113 Simulation Using Electrodynamic Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5114 Simulation Using Conventional Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53191ch6
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Chapter 6 Machine Condition Monitoring and Fault Diagnostics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 61 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 62 Machinery Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 621 Causes of Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 622 Types of Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 623 Frequency of Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 63 Basic Maintenance Strategies
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 631 Run-to-Failure (Breakdown) Maintenance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 632 Scheduled (Preventative) Maintenance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 633 Condition-Based (Predictive Proactive Reliability Centered On-Condition) Maintenance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 64 Factors Which Influence Maintenance Strategy
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 65 Machine Condition Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 651 Periodic Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 652 Continuous Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 66 Transducer Selection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 661 Noncontact Displacement Transducers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 662 Velocity Transducers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 663 Acceleration Transducers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 67 Transducer Location
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 68 Recording and Analysis Instrumentation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 681 Vibration Meters
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 682 Data Collectors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 683 Frequency-Domain Analyzers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 684 Time-Domain Instruments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 685 Tracking Analyzers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 69 Display Formats and Analysis Tools
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 691 Time Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6911 Time-Waveform Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6912 Time-Waveform Indices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6913 Time-Synchronous Averaging
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6914 Negative Averaging
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6915 Orbits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6916 Probability Density Functions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6917 Probability Density Moments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 692 Frequency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6921 Band-Pass Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6922 Shock Pulse (Spike Energy)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6923 Enveloped Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6924 Signature Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6925 Cascades (Waterfall Plots)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6926 Masks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6927 Frequency-Domain Indices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 693 Modal Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 694 Quefrency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 610 Fault Detection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 6101 Standards
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61011 Standards Based on Machinery Type
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61012 Standards Based on Vibration Severity
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 6102 Acceptance Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 61021 Statistical Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 6103 Frequency-Domain Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61031 Limited Band Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61032 Constant Bandwidth Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61033 Constant Percentage Bandwidth Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 611 Fault Diagnostics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 6111 Forcing Functions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61111 Unbalance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61112 Misalignment
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61113 Mechanical Looseness
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61114 Soft Foot
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61115 Rubs
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61116 Resonances
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61117 Oil Whirl
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61118 Oil Whip
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61119 Structural Vibrations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 611110 Foundation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 6112 Specific Machine Components
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 61121 Damaged or Worn Rolling-Element Bearings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 61122 Damaged or Worn Gears
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 6113 Specific Machine Types
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61131 Pumps
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61132 Fans
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61133 Electric Motors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61134 Steam and Gas Turbines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61135 Compressors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61136 Reciprocating Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 6114 Advanced Fault Diagnostic Techniques
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 53191ch7
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • Chapter 7 Vibration-Based Tool Condition Monitoring Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 71 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 72 Mechanics of Turning
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 721 General Terms
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 722 Chatter Vibrations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 723 Tool Wear
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7231 Tool Failure Mechanisms
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7232 Tool Failure Modes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7233 Tool Wear Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7234 Tool Wear Stages
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 73 Vibration Signal Recording
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 731 Direct and Indirect Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 732 Sensor Requirements for Tool Wear Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 733 Force Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7331 Direct Measurement Dynamometers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7332 Indirect Force Sensors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7333 Piezoelectric Strain Sensors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7334 Resistance Strain Gauges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7335 Customized Force Sensors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 734 Acceleration Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 735 Acoustic Emission Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 736 Sensor Comparisons
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 74 Signal Processing for Sensor-Based Tool Condition Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 741 Feature Extraction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7411 Time Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7412 Frequency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7413 Statistical Processing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7414 TimendashFrequency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 742 Feature Selection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 75 Wear ModelDecision-Making for Sensor-Based Tool Condition Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 751 Trending Threshold
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 752 Neural Networks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7521 Unsupervised Networks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7522 Supervised Networks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 753 Fuzzy Logic
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 754 Other Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 76 Conclusion
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53191ch8
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Chapter 8 Fault Diagnosis of Helicopter Gearboxes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 81 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 82 Abnormality Scaling
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 83 The Structure-Based Connectionist Network
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 84 Sensor Location Selection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 841 Coverage Index
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 842 Overlap Index
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 843 Monitoring Effectiveness
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 85 A Case Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 851 Structural and Featural Influences
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 852 Evaluation of Influences
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 853 Fault Detection Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 854 Fault Diagnostic Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 8541 Faulty Subsystem Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 8542 Faulty Component Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 855 Sensor Location Evaluation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 856 Sensor Location Validation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 86 Conclusion
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 53191ch9
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Chapter 9 Vibration Suppression and Monitoring in Precision Motion Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 91 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 92 Mechanical Design to Minimize Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 921 Stability and Static Determinacy of Machine Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 922 Two-Dimensional Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 923 Three-Dimensional Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 93 Adaptive Notch Filter
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 931 Fast Fourier Transform
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 932 Simulation and Experiments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 94 Real-Time Vibration Analyzer
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 941 Learning Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 942 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 943 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 944 Experiments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 9441 Input Variables mdash the Evaluation Criteria
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 94411 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 94412 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 9442 Evaluation Rules
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 94421 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 94422 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 9443 Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 94431 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 94432 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 95 Practical Insights and Case Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 96 Conclusions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 53191ch10
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Chapter 10 Vibration and Shock Problems of Civil Engineering Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 101 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 102 Earthquake-Induced Vibration of Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1021 Seismicity and Ground Motions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1022 Influence of Local Site Conditions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1023 Response of Structures to Ground Motions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1024 Dynamic Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10241 Equations of Motion for Linear Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10242 Equations of Motion for Linear Multiple-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1025 Earthquake Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10251 Elastic Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10252 Smoothed Design Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10253 Ductility-Modified Response Spectrum Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1026 Design Philosophy and the Code Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10261 Performance-Based Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1027 Analysis Options for Earthquake Effects
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10271 Dynamic Time History Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10272 Response Spectrum Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 102721 Response Spectrum Analysis of Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 102722 Response Spectrum Analysis of Multi-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10273 Equivalent Static Analysis (Force-Based Approach)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10274 Displacement-Based Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1028 SoilndashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1029 Active and Passive Control Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 10210 Worked Examples
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 103 Dynamic Effects of Wind Loading on Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1031 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1032 Wind Speed
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1033 Design Structures for Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10331 Types of Wind Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10332 Design Criteria
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10333 Static Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1034 Along and Across-Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10341 Along-Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10342 Across-Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1035 Wind Tunnel Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1036 Comfort Criteria Human Response to Building Motion
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1037 Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1038 Comparison with Earthquake Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 104 Vibrations Due to Fluid ndashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1041 Added Mass and Inertial Coupling
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1042 Wave-Induced Vibration of Structure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 105 Blast Loading and Blast Effects on Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1051 Explosions and Blast Phenomenon
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1052 Explosive Air-Blast Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10521 Blast Wave Scaling Laws
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10522 Prediction of Blast Pressure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1053 Gas Explosion Loading and Effect of Internal Explosions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1054 Structural Response to Blast Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10541 Elastic Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10542 Elasto-Plastic Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1055 Material Behaviors at High Strain Rate
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10551 Dynamic Properties of Concrete under High Strain Rates
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10552 Dynamic Properties of Reinforcing Steel under High Strain Rates
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1056 Failure Modes of Blast-Loaded Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10561 Global Structural Behavior
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10562 Localized Structural Behavior
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10563 PressurendashImpulse ( PndashI ) Diagrams
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1057 Blast WavendashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1058 Effect of Ground Shocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10581 Loads from Air-Induced Ground Shock
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10582 Loads from Direct Ground Shock
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1059 Technical Design Manuals for Blast-Resistant Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 10510 Computer Programs for Blast and Shock Effects
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 106 Impact Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1061 Structural Impact between Two Bodies mdash Hard Impact and Soft Impact
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1062 Example mdash Aircraft Impact
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 107 Floor Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1071 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1072 Types of Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10721 Walking
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10722 Rhythmic Activities
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10723 Mechanical Equipment
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10724 Analysis Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1073 Natural Frequency of Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10731 Computing the Natural Frequency
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10732 Computing Deflection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10733 Damping
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10734 Resonance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1074 Vibration Caused by Walking
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10741 Minimum Natural Frequency
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1075 Design for Rhythmic Excitation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10751 Harmonics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10752 Minimum Natural Frequency
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1076 Example mdash Vibration Analysis of a Reinforced Concrete Floor
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 53191ch11
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Chapter 11 Seismic Base Isolation and Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 111 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1111 From Ductility Design to Base Isolation and Control Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1112 The Importance of Reducing Seismic Input and Response
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 112 Seismic Base Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1121 Historical Development of Base Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1122 Basic Principle
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1123 Issues in Seismic Base Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11231 Performance Criteria
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11232 Type of Structure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11233 Site Characteristics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11234 Retrofit Issues
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11235 Design of Building Services
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11236 Expected Life of Isolator
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1124 Seismic Isolation Devices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11241 Laminated Rubber Bearings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11242 Lead Rubber Bearing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11243 Friction-Based Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11244 Other Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1125 Design of Isolation Devices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11251 High-Damping Rubber Bearing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112511 Stability against Buckling
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112512 Stability against Roll Out
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11252 Lead Rubber Bearings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112521 Design of Lead Plug
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112522 Design of Laminated Rubber Bearing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11253 Design of Friction Pendulum System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1126 Verification of Properties of Isolation Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11261 Tests for Isolation Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 112611 System Characterization Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 112612 Prototype Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 112613 Quality Control Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11262 Uniform Building Code Recommendations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112621 Units Dependent on Loading Rates
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112622 Units Dependent on Bilateral Load
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112623 System Adequacy
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1127 Analysis of Base-Isolated Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11271 Modeling of a Superstructure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11272 Modeling of Isolation System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11273 Static Analysis Procedure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11274 Dynamic Analysis Procedure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 112741 Response Spectrum Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 112742 Time-History Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11275 Software for Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1128 Experimental Methods for Isolated Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1129 Implementation of Seismic Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11291 New Construction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112911 Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112912 Bridges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11292 Seismic Retrofit
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112921 Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112922 Bridges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11293 Other Implementations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 11210 Performance during Past Earthquakes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 112101 Performance of Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 112102 Performance of Bridges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 113 Seismic Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1131 Historical Development of Seismic Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1132 Basic Principles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11321 Passive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11322 Active Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11323 Semiactive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11324 Hybrid Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11325 Categorization of Basic Principles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1133 Important Issues in Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11331 SoilndashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11332 DevicendashStructure Interaction and Time Delay
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11333 Design Guidelines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1134 Vibration-Control Devices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11341 Passive Control Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113411 Metallic Yielding Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113412 Friction Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113413 Viscoelastic Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113414 Viscous Fluid Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113415 Tuned Mass Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11342 Active Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113421 Electromagnetic Actuator
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113422 Hydraulic Actuators
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11343 Semiactive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113431 Variable-Orifice Hydraulic Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113432 Controllable Fluid Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113433 Controllable Friction Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11344 Hybrid Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1135 Control Algorithm
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11351 Active Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11352 Semiactive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113521 Common Control Schemes for Controllable Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113522 Special Control Schemes for Controllable Damper
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1136 Experimental Performance Verification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11361 Shaking Table Tests of a Flexible Structural Model with TMD AMD and ATMD
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11362 Substructure Hybrid Test
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113621 Hybrid Tests Using Hydraulic Actuator
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113622 Hybrid Tests Using Shaking Table
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113623 Hybrid Tests Using Inertia-Force-Driven Loading System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1137 Implementations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11371 Semiactive Control of Full-Scale Structures Using Variable Joint Damper System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113711 Background of Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113712 Test System Set Up
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113713 Control Algorithm
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113714 Test Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11372 Application of Structural Control Technologies to Seismic Retrofit of a Cable-Stayed Bridge
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113721 Background of Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113722 Basic Concept of Seismic Retrofit
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113723 Modal Shape Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113724 Time-History Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113725 Soil ndash Structure Interaction Effect
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113726 Semiactive Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53191ch12
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Chapter 12 Seismic Random Vibration of Long-Span Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 121 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1211 Basic Concepts of Random Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12111 Stationary Random Process
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12112 Nonstationary Random Process
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1212 Three Methods for Structural Seismic Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12121 Response Spectrum Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12122 Time-History Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12123 Random Vibration Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 121231 Davenport Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 121232 Vanmarcke Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 12124 Comparisons of the Three Seismic-Analysis Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 122 Seismic Random-Excitation Fields
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1221 Power Spectral Density of Spatially Varying Ground Acceleration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1222 Several Coherence Models
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12221 FengndashHu Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12222 Harichandran ndashVanmarcke Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12223 LohndashYeh Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12224 OliveirandashHaondashPenzien Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12225 LucondashWong Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12226 QundashWangndashWang Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1223 Generation of Ground Acceleration Power Spectral Density Curves from Acceleration Response Spectrum Curves
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12231 Kaul Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12232 Iteration Scheme
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1224 Seismic Equations of Motion of Long-Span Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1225 Seismic Waves and Their Geometrical Expressions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 123 Pseudoexcitation Method for Structural Random Vibration Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1231 Structures Subjected to Stationary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12311 Single Stationary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12312 Multiple Stationary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1232 Structures Subjected to Nonstationary Random Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12321 Structures Subjected to Uniformly Modulated Evolutionary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 123211 Single Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 123212 Multiple Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12322 Structures Subjected to Nonuniformly Modulated Evolutionary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 123221 Single Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 123222 Multiple Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1233 Precise Integration Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12331 Precise Integration of Exponential Matrices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12332 Particular Solutions and Precise Integration Formulas for Various Forms of Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 123321 Linear Loading Form (HPD-L Form)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 123322 Sinusoidal Loading Form (HPD-S Form)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 123323 Exponentially Decaying Sinusoidal Loading Form (HPD-E Form)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 124 Long-Span Structures Subjected to Stationary Random Ground Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1241 The Solution of Equations of Motion Using the Pseudoexcitation Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1242 Numerical Comparisons with Other Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12421 Song-Hua-Jiang Suspension Bridge
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 124211 All Supports Move Uniformly
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 124212 Wave Passage Effect Is Taken into Account
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 124213 Wave-Passage Effect and Incoherence Effect Are Jointly Taken into Account
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 12422 San Joaquin Concrete Bridge
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 125 Long-Span Structures Subjected to Nonstationary Random Ground Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1251 Modulation Functions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1252 The Formulas for Nonstationary Multiexcitation Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1253 Expected Extreme Values of Nonstationary Random Processes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1254 Numerical Comparisons with the Corresponding Stationary Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 126 Conclusions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 53191ch13
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Chapter 13 Seismic Qualification of Equipment
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 131 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 132 Distribution Qualification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1321 Drive-Signal Generation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1322 Distribution Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1323 Test Procedures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 133 Seismic Qualification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1331 Stages of Seismic Qualification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1332 Test Preliminaries
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1333 Single-Frequency Testing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1334 Multifrequency Testing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1335 Generation of RRS Specifications
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 53191ch14
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Chapter 14 Human Response to Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 141 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 142 Vibration Excitations on Humans
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1421 Excitation Characteristics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 143 Human Response to Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1431 Vibration Perception
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1432 Frequency Weighting Curve
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1433 Iso-Perception Curves
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1434 Detection Threshold Curve
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 144 Regulation of Human Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1441 Acceptable Vibration Levels in Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1442 Whole-Body Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1443 HandndashArm Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
Page 21: Vibration Monitoring, Testing, and Instrumentationpreview.kingborn.net › 646000 › d1a74678d91943e5ba1d5e... · The MEMS Handbook, Second Edition MEMS: Introduction and Fundamentals

1214 Hydraulic Shakers

A typical hydraulic shaker consists of a piston-cylinder arrangement (also called a ram) a servo-valve a

fluid pump and a driving electric motor Hydraulic fluid (oil) is pressurized (typical operating pressure

4000 psi) and pumped into the cylinder through a servo-valve by means of a pump that is driven by an

electric motor (typical power 150 hp) The flow (typical rate 100 galmin) that enters the cylinder is

controlled (modulated) by the servo-valve which in effect controls the resulting piston (ram) motion

A typical servo-valve consists of a two-stage spool valve which provides a pressure difference and a

controlled (modulated) flow to the piston which sets it in motion

The servo-valve itself is moved by means of a linear torque motor which is driven by the excitation-

input signal (electrical) A primary function of the servo-valve is to provide a stabilizing feedback to the

ram In this respect the servo-valve complements the main control system of the test setup The ram is

coupled to the shaker table by means of a link with some flexibility The cylinder frame is mounted on the

support foundation with swivel joints This allows for some angular and lateral misalignment which

might be caused primarily by test-object dynamics as the table moves

Two-degree-of-freedom (Two-DoF) testing requires two independent sets of actuators and three-DoF

testing requires three independent actuator sets Each independent actuator set can consist of several

actuators operated in parallel using the same pump and the same excitation-input signal to the torque

motors

If the test table is directly supported on the vertical actuators they must withstand the total dead

weight (ie the weight of the test table the test object the mounting fixtures and the instrumentation)

This is requirement is usually prevented by providing a pressurized air cushion in the gap between the

test table and the foundation walls Air should be pressurized so as to balance the total dead weight

exactly (typical required gage pressure 3 psi)

Figure 15(a) shows the basic components of a typical hydraulic shaker The corresponding

operational block diagram is shown in Figure 15(b) It is desirable to locate the actuators in a pit in the

test laboratory so that the test tabletop is flushed with the test laboratory floor under no-load conditions

This minimizes the effort required to place the test object on the test table Otherwise the test object has

to be lifted onto the test table with a forklift Also installation of an aircushion to support the system

dead weight is difficult under these circumstances of elevated mounting

Hydraulic actuators are most suitable for heavy load testing and are widely used in industrial and civil

engineering applications They canbeoperated at very low frequencies (almost direct current [DC]) aswell

as at intermediate frequencies (see Table 11) Large displacements (stroke) are possible at low frequencies

Hydraulic shakers have the advantage of providing high flexibility of operation during the test their

capabilities include variable-force and constant-force testing and wide-band random-input testing The

velocity and acceleration capabilities of hydraulic shakers are moderate Although any general excitation-

input motion (for example sine wave sine beat wide-band random) can be used in hydraulic shakers

faithful reproduction of these signals is virtually impossible at high frequencies because of distortion and

higher-order harmonics introduced by the high noise levels that are common in hydraulic systems This

is only a minor drawback in heavy-duty intermediate-frequency applications Dynamic interactions are

reduced through feedback control

1215 Inertial Shakers

In inertial shakers or ldquomechanical excitersrdquo the force that causes the shaker-table motion is generated by

inertia forces (accelerating masses) Counter-rotating-mass inertial shakers are typical in this category

To understand their principle of operation consider two equal masses rotating in opposite directions at

the same angular speed v and in the same circle of radius r (see Figure 16) This produces a resultant

force equal to 2mv2r cos vt in a fixed direction (the direction of symmetry of the two rotating arms)

Consequently a sinusoidal force with a frequency of v and an amplitude proportional to v2 is generated

This reaction force is applied to the shaker table

Figure 17 shows a sketch of a typical counter-rotating-mass inertial shaker It consists of two identical

rods rotating at the same speed in opposite directions Each rod has a series of slots in which to

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copy 2007 by Taylor amp Francis Group LLC

place weights In this manner the magnitude of

the eccentric mass can be varied to achieve various

force capabilities The rods are driven by a

variable-speed electric motor through a gear

mechanism that usually provides several speed

ratios A speed ratio is selected depending on the

required test-frequency range The whole system is

symmetrically supported on a carriage that is

directly connected to the test table The test object

is mounted on the test table The preferred

mounting configuration is horizontal so that the

excitation force is applied to the test object in a

horizontal direction In this configuration there

are no variable gravity moments (weight pounddistance to center of gravity) acting on the drive

mechanism Figure 17 shows the vertical con-

figuration In dynamic testing of large structures

the carriage can be mounted directly on the

structure at a location where the excitation force

should be applied By incorporating two pairs of

counter-rotating masses it is possible to generate

test moments as well as test forces

FIGURE 15 A typical hydraulic shaker arrangement (a) schematic diagram (b) operational block diagram

m m

2mw2r cos wt

wtw w

wt

FIGURE 16 Principle of operation of a counter-

rotating-mass inertial shaker

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copy 2007 by Taylor amp Francis Group LLC

Reaction-type shakers driven by inertia are widely used for the prototype testing of civil engineering

structures Their first application dates back to 1935 Inertial shakers are capable of producing

intermediate excitation forces The force generated is limited by the strength of the carriage frame The

frequency range of operation and the maximum velocity and acceleration capabilities are also

intermediate for inertial shakers whereas the maximum displacement capability is typically low A major

limitation of inertial shakers is that their excitation force is exclusively sinusoidal and that the force

amplitude is directly proportional to the square of the excitation frequency As a result complex and

random excitation testing constant-force testing (for example transmissibility tests and constant-force

sine-sweep tests) and flexibility to vary the force amplitude or the displacement amplitude during a test

are not generally feasible with this type of shakers Excitation frequency and amplitude can be varied

during testing however by incorporating a variable-speed drive for the motor The sinusoidal excitation

generated by inertial shakers is virtually undistorted which gives them an advantage over the other types

of shakers when used in sine-dwell and sine-sweep tests Small portable shakers with low-force capability

are available for use in on-site testing

1216 Electromagnetic Shakers

In electromagnetic shakers or ldquoelectrodynamic excitersrdquo the motion is generated using the principle of

operation of an electric motor Specifically the excitation force is produced when a variable excitation

signal (electrical) is passed through a moving coil placed in a magnetic field

The components of a commercial electromagnetic shaker are shown in Figure 18 A steady magnetic

field is generated by a stationary electromagnet that consists of field coils wound on a ferromagnetic base

that is rigidly attached to a protective shell structure The shaker head has a coil wound around it When

the excitation electrical signal is passed through this drive coil the shaker head which is supported on

flexure mounts will be set in motion The shaker head consists of the test table on which the test object

is mounted Shakers with interchangeable heads are available The choice of appropriate shaker head is

based on the geometry and mounting features of the test object The shaker head can be turned to

different angles by means of a swivel joint In this manner different directions of excitation (in biaxial

and triaxial testing) can be obtained

FIGURE 17 Sketch of a counter-rotating-mass inertial shaker

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122 Dynamics of Electromagnetic Shakers

Consider a single axis electromagnetic shaker (Figure 18) with a test object having a single natural

frequency of importance within the test frequency range The dynamic interactions between the shaker

and the test object give rise to two significant natural frequencies (and correspondingly two significant

resonances) These appear as peaks in the frequency response curve of the test setup Furthermore the

natural frequency (resonance) of the test package alone causes a ldquotroughrdquo or depression (antiresonance)

in the frequency response curve of the overall test setup To explain this characteristic consider the

dynamic model shown in Figure 19 The following mechanical parameters are defined for

Figure 19(a) m k and b are the mass stiffness and equivalent viscous damping constant respectively

of the test package and me ke and be are the corresponding parameters of the exciter (shaker) Also in

the equivalent electrical circuit of the shaker head as shown in Figure 19(b) the following electrical

parameters are defined Re and Le are the resistance and (leakage) inductance and kb is the back

electromotive force (back emf) of the linear motor Assuming that the gravitational forces are supported

FIGURE 18 Schematic sectional view of a typical electromagnetic shaker manufactured by Bruel and Kjaer

Denmark

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copy 2007 by Taylor amp Francis Group LLC

by the static deflections of the flexible elements and that the displacements are measured from the static

equilibrium position we have the following system equations

Test object meuroy frac14 2kethy2 yeTHORN2 beth_y2 _yeTHORN eth119THORNShaker head me euroye frac14 fe thorn kethy2 yeTHORN thorn beth_y2 _yeTHORN2 key 2 be _ye eth120THORN

Electrical Lediedt

thorn Reie thorn kb _ye frac14 vethtTHORN eth121THORN

The electromagnetic force fe generated in the shaker head is a result of the interaction of the magnetic

field generated by the current ie with coil of the moving shaker head and the constant magnetic field

(stator) in which the head coil is located Here we have

fe frac14 kbie eth122THORNNote that v(t) is the voltage signal that is applied by the amplifier to the shaker coil ye is the displacement

of the shaker head and y is the displacement response of the test package

It is assumed that kb has consistent electrical and mechanical units (Vmsec and NA) Usually

the electrical time constant of the shaker is quite small compared with the primarily mechanical

time constants of the shaker and the test package In such cases the Ledie=dt term in Equation 121 may

be neglected Consequently the equations from Equation 119 through Equation 122 may be

expressed in the Laplace (frequency) domain with the Laplace variable s taking the place of the derivative

d=dt as

ethms2 thorn bsthorn kTHORNy frac14 ethbsthorn kTHORNye eth123THORN

FIGURE 19 Dynamic models of an electromagnetic shaker and a flexible test package (a) mechanical model

(b) electrical model

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copy 2007 by Taylor amp Francis Group LLC

frac12mes2 thorn ethbthorn beTHORNsthorn ethkthorn keTHORN ye frac14 ethbsthorn kTHORNy thorn kb

Rev2

k2bs

Reye eth124THORN

It follows that the transfer function of the shaker head motion with respect to the excitation voltage is

given by

yevfrac14 kb

Re

DethsTHORNDdethsTHORN eth125THORN

where DethsTHORN is the characteristic function of the primary dynamics of the test object

DethsTHORN frac14 ms2 thorn bsthorn k eth126THORN

and DdethsTHORN is the characteristic function of the primary dynamic interactions between the shaker and thetest object

DcethsTHORN frac14 mmes4 thorn frac12methbe thorn bthorn boTHORN thornmeb s

3 thorn frac12methke thorn kTHORN thornmekthorn bethbe thorn boTHORN s2thorn frac12bke thorn ethbe thorn boTHORNk sthorn kke

eth127THORN

where

bo frac14 k2bRe

eth128THORN

It is clear that under low damping conditions DdethsTHORN will produce two resonances as it is fourth order in sand similarly DethsTHORN will produce one antiresonance (trough) corresponding to the resonance of the testobject Note that in the frequency domain s frac14 jv and hence the frequency response function given by

Equation 125 is in fact

yevfrac14 kb

Rb

DethjvTHORNDdethjvTHORN eth129THORN

The magnitude of this frequency response function for a typical test system is sketched in Figure 110

Note that this curve is for the ldquoopen-looprdquo case where there is no feedback from the shaker controller

In practice the shaker controller will be able

to compensate for the resonances and anti-

resonances to some degree depending on its

effectiveness

The main advantages of electromagnetic

shakers are their high frequency range of

operation their high degree of operating flexi-

bility and the high level of accuracy of the

generated shaker motion Faithful reproduction

of complex excitations is possible because of the

advanced electronics and control systems used in

this type of shakers Electromagnetic shakers are

not suitable for heavy-duty applications (large test

objects) however High test-input accelerations

are possible at high frequencies when electromag-

netic shakers are used but their displacement and

velocity capabilities are limited to low or

intermediate values (see Table 11)

100

10

1 10 100Excitation Frequency (Hz)

Antiresonance

Resonance

Shak

erD

ispl

acem

entM

agni

tude

Resonance

1000

FIGURE 110 Frequency response curve of a typical

electromagnetic shaker with a test object

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1221 Transient Exciters

Other varieties of exciters are commonly used in

transient-type vibration testing In these tests

either an impulsive force or an initial excitation is

applied to the test object and the resulting

response is monitored The excitations and the

responses are ldquotransientrdquo in this case Hammer

test drop tests and pluck tests fall into this

category For example a hammer test may be

conducted by hitting the object with an instru-

mented hammer and then measuring the response

of the object The hammer has a force sensor at its

tip as sketched in Figure 111 A piezoelectric or

strain-gage type force sensor may be used More

sophisticated hammers have impedance heads in

place of force sensors An impedance head

measures force and acceleration simultaneously

The results of a hammer test will depend on many

factors for example the dynamics of the hammer

body how firmly the hammer is held during the

impact how quickly the impact is applied and

whether there are multiple impacts

13 Control System

The two primary functions of the shaker control system in vibration testing are (1) to guarantee that the

specified excitation is applied to the test object and (2) to ensure that the dynamic stability (motion

constraints) of the test setup is preserved An operational block diagram illustrating these control

functions is given in Figure 112 The reference input to the control system represents the desired

excitation force that should be applied to the test object In the absence of any control however the force

reaching the test object will be distorted primarily because of (1) dynamic interactions and

nonlinearities of the shaker the test table the mounting fixtures the auxiliary instruments and the test

object itself (2) noise and errors in the signal generator amplifiers filters and other equipment and (3)

external loads and disturbances acting on the test object and other components (for example external

restraints aerodynamic forces friction) To compensate for these distorting factors response

measurements (displacements velocities acceleration and so on) are made at various locations in the

test setup and are used to control the system dynamics In particular the responses of the shaker the test

table and the test object are measured These responses are used to compare the actual excitation felt by

FIGURE 111 An instrumented hammer used in bump

tests or hammer tests

ExcitationInput

(Reference)

Feedback Paths

DriveSignal

ShakerResponse

TestTable

TestObject

Test ObjectResponse

Test TableResponseExciter

(Shaker)(Ram)

Controllerand

Amplifier

FIGURE 112 Operational block diagram illustrating a general shaker control system

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copy 2007 by Taylor amp Francis Group LLC

the test object at the shaker interface with the desired (specified) input The drive signal to the shaker is

modified depending on the error that is present

Two types of control are commonly employed in shaker apparatus simple manual control and

complex automatic control Manual control normally consists of simple open-loop trial-and-error

methods of manual adjustments (or calibration) of the control equipment to obtain a desired dynamic

response The actual response is usually monitored (on an oscilloscope or frequency analyzer screen for

example) during manual-control operations The pretest adjustments in manual control can be very

time-consuming as a result the test object might be subjected to overtesting which could produce

cumulative damage is undesirable and could defeat the test purpose Furthermore the calibration

procedure for the experimental setup must be repeated for each new test object

The disadvantages ofmanual control suggest that automatic control is desirable in complex test schemes

in which high accuracy of testing is desired The first step of automatic control involves automatic

measurement of the system response using control sensors and transducers The measurement is then fed

back into the control system which instantaneously determines the best drive signal to actuate the shaker

in order to get the desired excitation This may be done by either analog or digital methods

Primitive control systems require an accurate mathematical description of the test object This

dependency of the control system on the knowledge of test-object dynamics is clearly undesirable

Performance of a good control system should not be considerably affected by the dynamic interactions

and nonlinearities of the test object or by the nature of the excitation Proper selection of feedback signals

and control-system components can reduce such effects and will make the system robust

In the response-spectrum method of vibration testing it is customary to use displacement control at

low frequencies velocity control at intermediate frequency and acceleration control at high frequencies

This necessitates feedback of displacement velocity and acceleration responses Generally however the

most important feedback is the velocity feedback In sine-sweep tests the shaker velocity must change

steadily over the frequency band of interest In particular the velocity control must be precise near the

resonances of the test object Velocity (speed) feedback has a stabilizing effect on the dynamics which is

desirable This effect is particularly useful in ensuring stability in motion when testing is done near

resonances of lightly damped test objects On the contrary displacement (position) feedback can have a

destabilizing effect on some systems particularly when high feedback gains are used

The controller usually consists of various instruments equipment and computation hardware and

software Often the functions of the data-acquisition and processing system overlap with those of the

controller to some extent As an example consider the digital-controller of vibration testing apparatus

First the responses are measured through sensors (and transducers) filtered and amplified

(conditioned) These data channels may be passed through a multiplexer whose purpose is to select

one data channel at a time for processing Most modern data acquisition hardware does not need a

separate multiplexer to handle multiple signals The analog data are converted into digital data using

analog-to-digital converters (ADCs) The resulting sampled data are stored on a disk or as a block data in

the computer memory The reference input signal (typically a signal recorded on an FM tape) is also

sampled (if it is not already in the digital form) using an ADC and fed into the computer Digital

processing is done on the reference signal and the response data with the objective of computing the

command signal to drive the shaker The digital command signal is converted into an analog signal using

a digital-to-analog converter (DAC) and amplified (conditioned) before it is used to drive the exciter

The nature of the control components depends to a large extent on the nature and objectives of the

particular test to be conducted Some of the basic components in a shaker controller are described in

the following subsections

131 Components of a Shaker Controller

1311 Compressor

A compressor circuit is incorporated in automatic excitation control devices to control the excitation-

input level automatically The level of control depends on the feedback signal from a control sensor and

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copy 2007 by Taylor amp Francis Group LLC

the specified (reference) excitation signal Usually the compressor circuit is included in the excitation-

signal generator (for example in a sine generator) The control by this means may be done on the basis of

a single-frequency component (eg the fundamental frequency)

1312 Equalizer (Spectrum Shaper)

Random-signal equalizers are used to shape the spectrum of a random signal in a desired manner In

essence and equalizer consists of a bank of narrow-band filters (for example 80 filters) in parallel over

the operating frequency range By passing the signal through each filter the spectral density (or the mean

square value) of the signal in that narrow frequency band (for example each one-third-octave band) is

determined This is compared with the desired spectral level and automatic adjustment is made in that

filter in case there is an error In some systems response-spectrum analysis is made in place of power

spectral density analysis In that case the equalizer consists of a bank of simple oscillators whose

resonant frequencies are distributed over the operating frequency range of the equalizer The feedback

signal is passed through each oscillator and the peak value of its output is determined This value is

compared with the desired response spectrum value at that frequency If there is an error automatic gain

adjustment is made in the appropriate excitation signal components

Random-noise equalizers are used in conjunction with random signal generators They receive

feedback signals from the control sensors In some digital control systems there are algorithms (software)

that are used to iteratively converge the spectrum of the excitation signal felt by the test object into the

desired spectrum

1313 Tracking Filter

Many vibration tests are based on single-frequency excitations In such cases the control functions

should be performed on the basis of the amplitudes of the fundamental-frequency component of the

signal A tracking filter is simply a frequency-tuned band-pass filter It automatically tunes the center

frequency of its very narrow-band-pass filter to the frequency of a carrier signal Then when a noisy

signal is passed through the tuned filter the output of the filter will be the required fundamental

frequency component in the signal Tracking filters also are useful in obtaining amplitudendashfrequency

plots using an XndashY plotter In such cases the frequency value comes from the signal generator (sweep

oscillator) which produces the carrier signal to the tracking filter The tracking filter then determines the

corresponding amplitude of a signal that is fed into it Most tracking filters have dual channels so that two

signals can be handled (tracked) simultaneously

1314 Excitation Controller (Amplitude Servo-Monitor)

An excitation controller is typically an integral part of the signal generator It can be set so that automatic

sweep between two frequency limits can be performed at a selected sweep rate (linear or logarithmic)

More advanced excitation controllers have the capability of an automatic switch-over between constant-

displacement constant-velocity and constant-acceleration excitation-input control at specified

frequencies over the sweep frequency interval Consequently integrator circuits should be present

within the excitation controller unit to determine velocities and displacements from acceleration signals

Sometimes integration is performed by a separate unit called a vibration meter This unit also offers

the operator the capability of selecting the desired level of each signal (acceleration velocity or

displacement) There is an automatic cut-off level for large displacement values that could result from

noise in acceleration signals A compressor is also a subcomponent of the excitation controller The

complete unit is sometimes known as an amplitude servo-monitor

132 Signal-Generating Equipment

Shakers are force-generating devices that are operated using drive (excitation) signals generated from a

source The excitation-signal source is known as the signal generator Three major types of signal

generators are used in vibration testing applications (1) oscillators (2) random-signal generators and

(3) storage devices In some units oscillators and random-signal generators are combined We shall

Vibration Instrumentation 1-17

53191mdash522007mdash1202mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

discuss these two generators separately however because of their difference in function It also should be

noted that almost any digital signal (deterministic or random) can be generated by a digital computer

using a suitable computer program the signal eventually can be passed through a DAC to obtain

the corresponding analog signal These lsquodigitalrsquo signal generators along with analog sources such as

magnetic tape players (FM) are classified into the category of storage devices

The dynamic range of equipment is the ratio of the maximum and minimum output levels (expressed

in decibels) at which it is capable of operating without significant error This is an important specification

for many types of equipment particularly for signal-generating devices The output level of the signal

generator should be set to a value within its dynamic range

1321 Oscillators

Oscillators are essentially single-frequency generators Typically sine signals are generated but other

waveforms (such as rectangular and triangular pulses) are also available in most oscillators Normally

an oscillator has two modes of operation (1) sweeping up and down between two frequency limits and

(2) dwelling at a specified frequency In the sweep operation the sweep rate should be specified This can

be done either on a linear scale (Hzmin) or on a logarithmic scale (octavesmin) In the dwell operation

the frequency points (or intervals) should be specified In either case a desired signal level can be chosen

using the gain-control knob An oscillator that is operated exclusively in the sweep mode is called a sweep

oscillator

The early generation of oscillators employed variable inductor-capacitor types of electronic circuits to

generate signals oscillating at a desired frequency The oscillator is tuned to the required frequency by

varying the capacitance or inductance parameters A DC voltage is applied to energize the capacitor

and to obtain the desired oscillating voltage signal which subsequently is amplified and conditioned

Modern oscillators use operational amplifier circuits along with resistor capacitor and semiconductor

(SC) elements Also common are crystal (quartz) parallel-resonance oscillators used to generate voltage

signals accurately at a fixed frequency The circuit is activated using a DC-voltage source Other

frequencies of interest are obtained by passing this high-frequency signal through a frequency converter

The signal is then conditioned (amplified and filtered) Required shaping (for example rectangular

pulse) is obtained using a shape circuit Finally the required signal level is obtained by passing the

resulting signal through a variable-gain amplifier A block diagram of an oscillator illustrating various

stages in the generation of a periodic signal is given in Figure 113

A typical oscillator offers a choice of several (typically six) linear and logarithmic frequency ranges and

a sizable level of control capability (for example 80 dB) Upper and lower frequency limits in a sweep can

be preset on the front panel to any of the available frequency ranges Sweep-rate settings are continuously

DC Voltage

Oscillator

FrequencySpecification

FrequencyConverter

FilterAmplifier

ShaperPeriodicSignal

FrequencyCounter

Fixed-FrequencySignal

Variable-GainOutput

Amplifier

SignalSpecification

LevelSpecification

FIGURE 113 Block diagram of an oscillator-type signal generator

Vibration Monitoring Testing and Instrumentation1-18

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copy 2007 by Taylor amp Francis Group LLC

  • 53191fm
    • Vibration Monitoring Testing and Instrumentation
      • Preface
      • Acknowledgments
      • Editor-in-Chief
      • Contributors
      • Contents
      • Related Titles
          • 53191ch1
            • Table of Contents
            • Chapter 1 Vibration Instrumentation
              • Summary
              • 11 Introduction
              • 12 Vibration Exciters
                • 121 Shaker Selection
                  • 1211 Force Rating
                  • 1212 Power Rating
                  • 1213 Stroke Rating
                  • 1214 Hydraulic Shakers
                  • 1215 Inertial Shakers
                  • 1216 Electromagnetic Shakers
                    • 122 Dynamics of Electromagnetic Shakers
                      • 1221 Transient Exciters
                          • 13 Control System
                            • 131 Components of a Shaker Controller
                              • 1311 Compressor
                              • 1312 Equalizer (Spectrum Shaper)
                              • 1313 Tracking Filter
                              • 1314 Excitation Controller (Amplitude Servo-Monitor)
                                • 132 Signal-Generating Equipment
                                  • 1321 Oscillators
                                  • 1322 Random Signal Generators
                                  • 1323 Tape Players
                                  • 1324 Data Processing
                                      • 14 Performance Specification
                                        • 141 Parameters for Performance Specification
                                          • 1411 Time-Domain Specifications
                                          • 1412 Frequency-Domain Specifications
                                            • 142 Linearity
                                            • 143 Instrument Ratings
                                              • 1431 Rating Parameters
                                                • 144 Accuracy and Precision
                                                  • 15 Motion Sensors and Transducers
                                                    • 151 Potentiometer
                                                      • 1511 Potentiometer Resolution
                                                      • 1512 Optical Potentiometer
                                                        • 152 Variable-Inductance Transducers
                                                          • 1521 Mutual-Induction Transducers
                                                          • 1522 Linear-Variable Differential Transformer
                                                          • 1523 Signal Conditioning
                                                            • 153 Mutual-Induction Proximity Sensor
                                                            • 154 Selfinduction Transducers
                                                            • 155 Permanent-Magnet Transducers
                                                            • 156 Alternating Current Permanent-Magnet Tachometer
                                                            • 157 Alternating Current Induction Tachometer
                                                            • 158 Eddy Current Transducers
                                                            • 159 Variable-Capacitance Transducers
                                                              • 1591 Capacitive Displacement Sensors
                                                              • 1592 Capacitive Angular Velocity Sensor
                                                              • 1593 Capacitance Bridge Circuit
                                                                • 1510 Piezoelectric Transducers
                                                                  • 15101 Sensitivity
                                                                  • 15102 Piezoelectric Accelerometer
                                                                  • 15103 Charge Amplifier
                                                                      • 16 Torque Force and Other Sensors
                                                                        • 161 Strain Gage Sensors
                                                                          • 1611 Equations for Strain Gage Measurements
                                                                          • 1612 Bridge Sensitivity
                                                                          • 1613 The Bridge Constant
                                                                          • 1614 The Calibration Constant
                                                                          • 1615 Data Acquisition
                                                                          • 1616 Accuracy Considerations
                                                                          • 1617 Semiconductor Strain Gages
                                                                          • 1618 Force and Torque Sensors
                                                                          • 1619 Strain Gage Torque Sensors
                                                                          • 16110 Deflection Torque Sensors
                                                                          • 16111 Variable-Reluctance Torque Sensor
                                                                          • 16112 Reaction Torque Sensors
                                                                            • 162 Miscellaneous Sensors
                                                                              • 1621 Stroboscope
                                                                              • 1622 Fiber Optic Sensors and Lasers
                                                                              • 1623 Fiber-Optic Gyroscope
                                                                              • 1624 Laser Doppler Interferometer
                                                                              • 1625 Ultrasonic Sensors
                                                                              • 1626 Gyroscopic Sensors
                                                                                  • References
                                                                                  • Appendix 1A Virtual Instrumentation for Data Acquisition Analysis and Presentation
                                                                                    • Summary
                                                                                    • List of Abbreviations
                                                                                    • 1A1 Dynamic Signals
                                                                                      • 1A11 Acquiring and Simulating Dynamic Signals
                                                                                        • 1A111 Aliasing
                                                                                        • 1A112 Time Continuity
                                                                                            • 1A2 Measurement Configuration Considerations
                                                                                              • 1A21 Input Signal Considerations
                                                                                                • 1A211 Input Pseudodifferential and Differential Configuration
                                                                                                • 1A212 Gain
                                                                                                • 1A213 Input Coupling
                                                                                                • 1A214 Integrated Electronic Piezoelectric Excitation
                                                                                                • 1A215 Nyquist Frequency and Bandwidth
                                                                                                • 1A216 Analog-to-Digital Conversion
                                                                                                • 1A217 Antialias Filters
                                                                                                • 1A218 Input Filter Delay
                                                                                                • 1A219 Overload Detection
                                                                                                  • 1A22 Output Signal Considerations
                                                                                                    • 1A221 Output Pseudodifferential and Differential Configuration
                                                                                                    • 1A222 Attenuation
                                                                                                    • 1A223 Digital-to-Analog Conversion
                                                                                                    • 1A224 Anti-imaging and Interpolation Filters
                                                                                                    • 1A225 Output Filter Delay
                                                                                                        • 1A3 Scaling and Calibration
                                                                                                          • 1A31 Scaling to Engineering Units
                                                                                                          • 1A32 Performing System Calibration
                                                                                                            • 1A321 Propagation Delay Calibration
                                                                                                                • 1A4 Limit Testing Analysis
                                                                                                                  • 1A41 Limit Testing Overview
                                                                                                                  • 1A42 Using the SVT Limit Testing VI
                                                                                                                    • 1A5 Integration
                                                                                                                      • 1A51 Introduction to Integration
                                                                                                                      • 1A52 Implementing Integration
                                                                                                                        • 1A521 Challenges when Integrating Vibration Data
                                                                                                                          • 1A53 Time-Domain Integration
                                                                                                                            • 1A531 Single-Shot Acquisition and Integration
                                                                                                                            • 1A532 Continuous Acquisition and Integration
                                                                                                                              • 1A54 Frequency-Domain Integration
                                                                                                                                • 1A6 Vibration-Level Measurements
                                                                                                                                  • 1A61 Measuring the Root Mean Square Level
                                                                                                                                    • 1A611 Single-Shot Buffered Acquisition
                                                                                                                                    • 1A612 Continuous Signal Acquisition
                                                                                                                                      • 1A62 Performing a Running RMS Level Measurement
                                                                                                                                      • 1A63 Computing the Peak Level
                                                                                                                                      • 1A64 Computing the Crest Factor
                                                                                                                                        • 1A7 Frequency Analysis
                                                                                                                                          • 1A71 FFT Fundamentals
                                                                                                                                            • 1A711 Number of Samples
                                                                                                                                            • 1A712 Frequency Resolution
                                                                                                                                            • 1A713 Maximum Resolvable Frequency
                                                                                                                                            • 1A714 Minimum Resolvable Frequency
                                                                                                                                            • 1A715 Number of Spectral Lines
                                                                                                                                            • 1A716 Relationship between Time-Domain and Frequency-Domain Specifications and Parameters
                                                                                                                                              • 1A72 Increasing Frequency Resolution
                                                                                                                                                • 1A721 Zoom FFT Analysis
                                                                                                                                                • 1A722 Frequency Resolution of the Zoom FFT VIs
                                                                                                                                                • 1A723 Zoom Measurement
                                                                                                                                                • 1A724 Zoom Settings
                                                                                                                                                • 1A725 Subset Analysis
                                                                                                                                                    • 1A8 Transient Analysis
                                                                                                                                                      • 1A81 Transient Analysis with the Sound and Vibration Toolkit
                                                                                                                                                      • 1A82 Performing an STFT vs Time
                                                                                                                                                        • 1A821 Selecting the FFT Block Size
                                                                                                                                                        • 1A822 Overlapping
                                                                                                                                                        • 1A823 Using the SVT STFT vs Time VI
                                                                                                                                                          • 1A83 Performing an STFT vs Rotational Speed
                                                                                                                                                            • 1A831 Converting the Pulse Train to Rotational Speed
                                                                                                                                                            • 1A832 STFT vs RPM
                                                                                                                                                              • 1A84 Measuring a Shock Response Spectrum
                                                                                                                                                                • 1A9 Waterfall Display
                                                                                                                                                                  • 1A91 Using the Display VIs
                                                                                                                                                                    • 1A911 Initializing the Display
                                                                                                                                                                    • 1A912 Sending Data to the Display
                                                                                                                                                                    • 1A913 Waterfall Display for Frequency Analysis
                                                                                                                                                                    • 1A914 Waterfall Display for Transient Analysis
                                                                                                                                                                    • 1A915 Waterfall Display for Octave Spectra
                                                                                                                                                                        • 1A10 Swept-Sine Measurements
                                                                                                                                                                          • 1A101 Swept-Sine Overview
                                                                                                                                                                          • 1A102 Choosing Swept-Sine vs FFT Measurements
                                                                                                                                                                          • 1A103 Taking a Swept-Sine Measurement
                                                                                                                                                                          • 1A104 Swept-Sine Measurement Example
                                                                                                                                                                              • Bibliography
                                                                                                                                                                              • Related Titles
                                                                                                                                                                                  • 53191ch2
                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                    • Chapter 2 Signal Conditioning and Modification
                                                                                                                                                                                      • Summary
                                                                                                                                                                                      • 21 Introduction
                                                                                                                                                                                      • 22 Amplifiers
                                                                                                                                                                                        • 221 Operational Amplifier
                                                                                                                                                                                        • 222 Use of Feedback in Opamp
                                                                                                                                                                                        • 223 Voltage Current and Power Amplifiers
                                                                                                                                                                                          • 2231 Charge Amplifiers
                                                                                                                                                                                            • 224 Instrumentation Amplifiers
                                                                                                                                                                                              • 2241 Differential Amplifier
                                                                                                                                                                                              • 2242 Common Mode
                                                                                                                                                                                                • 225 Amplifier Performance Ratings
                                                                                                                                                                                                  • 2251 Common-Mode Rejection Ratio
                                                                                                                                                                                                    • 226 Component Interconnection
                                                                                                                                                                                                      • 2261 Impedance Characteristics
                                                                                                                                                                                                      • 2262 Cascade Connection of Devices
                                                                                                                                                                                                      • 2263 AC-Coupled Ampliers
                                                                                                                                                                                                          • 23 Analog Filters
                                                                                                                                                                                                            • 231 Passive Filters and Active Filters
                                                                                                                                                                                                              • 2311 Number of Poles
                                                                                                                                                                                                                • 232 Low-Pass Filters
                                                                                                                                                                                                                  • 2321 Low-Pass Butterworth Filter
                                                                                                                                                                                                                    • 233 High-Pass Filters
                                                                                                                                                                                                                    • 234 Band-Pass Filters
                                                                                                                                                                                                                      • 2341 Resonance-Type Band-Pass Filters
                                                                                                                                                                                                                        • 235 Band-Reject Filters
                                                                                                                                                                                                                          • 24 Modulators and Demodulators
                                                                                                                                                                                                                            • 241 Amplitude Modulation
                                                                                                                                                                                                                              • 2411 Modulation Theorem
                                                                                                                                                                                                                              • 2412 Side Frequencies and Side Bands
                                                                                                                                                                                                                                • 242 Application of Amplitude Modulation
                                                                                                                                                                                                                                  • 2421 Fault Detection and Diagnosis
                                                                                                                                                                                                                                    • 243 Demodulation
                                                                                                                                                                                                                                      • 25 Analog ndashDigital Conversion
                                                                                                                                                                                                                                        • 251 Digital-to-Analog Conversion
                                                                                                                                                                                                                                          • 2511 DAC Error Sources
                                                                                                                                                                                                                                            • 252 Analog-to-Digital Conversion
                                                                                                                                                                                                                                            • 253 Analog-to-Digital Converter Performance Characteristics
                                                                                                                                                                                                                                              • 2531 Resolution and Quantization Error
                                                                                                                                                                                                                                              • 2532 Monotonicity Nonlinearity and Offset Error
                                                                                                                                                                                                                                              • 2533 Analog-to-Digital Converter Conversion Rate
                                                                                                                                                                                                                                                • 254 Sample-and-Hold Circuitry
                                                                                                                                                                                                                                                • 255 Digital Filters
                                                                                                                                                                                                                                                  • 2551 Software Implementation and Hardware Implementation
                                                                                                                                                                                                                                                      • 26 Bridge Circuits
                                                                                                                                                                                                                                                        • 261 Wheatstone Bridge
                                                                                                                                                                                                                                                        • 262 Constant-Current Bridge
                                                                                                                                                                                                                                                        • 263 Bridge Amplifiers
                                                                                                                                                                                                                                                          • 2631 Half-Bridge Circuits
                                                                                                                                                                                                                                                            • 264 Impedance Bridges
                                                                                                                                                                                                                                                              • 2641 Owen Bridge
                                                                                                                                                                                                                                                              • 2642 Wien-Bridge Oscillator
                                                                                                                                                                                                                                                                  • 27 Linearizing Devices
                                                                                                                                                                                                                                                                    • 271 Linearization by Software
                                                                                                                                                                                                                                                                    • 272 Linearization by Hardware Logic
                                                                                                                                                                                                                                                                    • 273 Analog Linearizing Circuitry
                                                                                                                                                                                                                                                                    • 274 Offsetting Circuitry
                                                                                                                                                                                                                                                                    • 275 Proportional-Output Circuitry
                                                                                                                                                                                                                                                                      • 2751 Curve-Shaping Circuitry
                                                                                                                                                                                                                                                                          • 28 Miscellaneous Signal Modification Circuitry
                                                                                                                                                                                                                                                                            • 281 Phase Shifters
                                                                                                                                                                                                                                                                            • 282 Voltage-to-Frequency Converter
                                                                                                                                                                                                                                                                            • 283 Frequency-to-Voltage Converter
                                                                                                                                                                                                                                                                            • 284 Voltage-to-Current Converters
                                                                                                                                                                                                                                                                            • 285 Peak-Hold Circuits
                                                                                                                                                                                                                                                                              • 29 Signal Analyzers and Display Devices
                                                                                                                                                                                                                                                                                • 291 Signal Analyzers
                                                                                                                                                                                                                                                                                • 292 Oscilloscopes
                                                                                                                                                                                                                                                                                  • 2921 Triggering
                                                                                                                                                                                                                                                                                  • 2922 Lissajous Patterns
                                                                                                                                                                                                                                                                                  • 2923 Digital Oscilloscopes
                                                                                                                                                                                                                                                                                      • Bibliography
                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                          • 53191ch3
                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                            • Chapter 3 Vibration Testing
                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                              • 31 Introduction
                                                                                                                                                                                                                                                                                              • 32 Representation of a Vibration Environment
                                                                                                                                                                                                                                                                                                • 321 Test Signals
                                                                                                                                                                                                                                                                                                  • 3211 Stochastic vs Deterministic Signals
                                                                                                                                                                                                                                                                                                    • 322 Deterministic Signal Representation
                                                                                                                                                                                                                                                                                                      • 3221 Single-Frequency Signals
                                                                                                                                                                                                                                                                                                      • 3222 Sine Sweep
                                                                                                                                                                                                                                                                                                      • 3223 Sine Dwell
                                                                                                                                                                                                                                                                                                      • 3224 Decaying Sine
                                                                                                                                                                                                                                                                                                      • 3225 Sine Beat
                                                                                                                                                                                                                                                                                                      • 3226 Sine Beat with Pauses
                                                                                                                                                                                                                                                                                                      • 3227 Multifrequency Signals
                                                                                                                                                                                                                                                                                                      • 3228 Actual Excitation Records
                                                                                                                                                                                                                                                                                                      • 3229 Simulated Excitation Signals
                                                                                                                                                                                                                                                                                                        • 323 Stochastic Signal Representation
                                                                                                                                                                                                                                                                                                          • 3231 Ergodic Random Signals
                                                                                                                                                                                                                                                                                                          • 3232 Stationary Random Signals
                                                                                                                                                                                                                                                                                                          • 3233 Independent and Uncorrelated Signals
                                                                                                                                                                                                                                                                                                          • 3234 Transmission of Random Excitations
                                                                                                                                                                                                                                                                                                            • 324 Frequency-Domain Representations
                                                                                                                                                                                                                                                                                                              • 3241 Fourier Spectrum Method
                                                                                                                                                                                                                                                                                                              • 3242 Power Spectral Density Method
                                                                                                                                                                                                                                                                                                                • 325 Response Spectrum
                                                                                                                                                                                                                                                                                                                  • 3251 Displacement Velocity and Acceleration Spectra
                                                                                                                                                                                                                                                                                                                  • 3252 Response-Spectra Plotting Paper
                                                                                                                                                                                                                                                                                                                  • 3253 Zero-Period Acceleration
                                                                                                                                                                                                                                                                                                                  • 3254 Uses of Response Spectra
                                                                                                                                                                                                                                                                                                                    • 326 Comparison of Various Representations
                                                                                                                                                                                                                                                                                                                      • 33 Pretest Procedures
                                                                                                                                                                                                                                                                                                                        • 331 Purpose of Testing
                                                                                                                                                                                                                                                                                                                        • 332 Service Functions
                                                                                                                                                                                                                                                                                                                          • 3321 Active Equipment
                                                                                                                                                                                                                                                                                                                          • 3322 Passive Equipment
                                                                                                                                                                                                                                                                                                                          • 3323 Functional Testing
                                                                                                                                                                                                                                                                                                                            • 333 Information Acquisition
                                                                                                                                                                                                                                                                                                                              • 3331 Interface Details
                                                                                                                                                                                                                                                                                                                              • 3332 Effect of Neglecting Interface Dynamics
                                                                                                                                                                                                                                                                                                                              • 3333 Effects of Damping
                                                                                                                                                                                                                                                                                                                              • 3334 Effects of Inertia
                                                                                                                                                                                                                                                                                                                              • 3335 Effect of Natural Frequency
                                                                                                                                                                                                                                                                                                                              • 3336 Effect of Excitation Frequency
                                                                                                                                                                                                                                                                                                                              • 3337 Other Effects of Interface
                                                                                                                                                                                                                                                                                                                                • 334 Test-Program Planning
                                                                                                                                                                                                                                                                                                                                  • 3341 Testing of Cabinet-Mounted Equipment
                                                                                                                                                                                                                                                                                                                                    • 335 Pretest Inspection
                                                                                                                                                                                                                                                                                                                                      • 34 Testing Procedures
                                                                                                                                                                                                                                                                                                                                        • 341 Resonance Search
                                                                                                                                                                                                                                                                                                                                        • 342 Methods of Determining Frequency-Response Functions
                                                                                                                                                                                                                                                                                                                                          • 3421 Fourier Transform Method
                                                                                                                                                                                                                                                                                                                                          • 3422 Spectral Density Method
                                                                                                                                                                                                                                                                                                                                          • 3423 Harmonic Excitation Method
                                                                                                                                                                                                                                                                                                                                            • 343 Resonance-Search Test Methods
                                                                                                                                                                                                                                                                                                                                              • 3431 Hammer (Bump) Test and Drop Test
                                                                                                                                                                                                                                                                                                                                              • 3432 Pluck Test
                                                                                                                                                                                                                                                                                                                                              • 3433 Shaker Tests
                                                                                                                                                                                                                                                                                                                                                • 344 Mechanical Aging
                                                                                                                                                                                                                                                                                                                                                  • 3441 Equivalence for Mechanical Aging
                                                                                                                                                                                                                                                                                                                                                  • 3442 Excitation-Intensity Equivalence
                                                                                                                                                                                                                                                                                                                                                  • 3443 Dynamic-Excitation Equivalence
                                                                                                                                                                                                                                                                                                                                                  • 3444 Cumulative Damage Theory
                                                                                                                                                                                                                                                                                                                                                    • 345 Test-Response Spectrum Generation
                                                                                                                                                                                                                                                                                                                                                    • 346 Instrument Calibration
                                                                                                                                                                                                                                                                                                                                                    • 347 Test-Object Mounting
                                                                                                                                                                                                                                                                                                                                                    • 348 Test-Input Considerations
                                                                                                                                                                                                                                                                                                                                                      • 3481 Test Nomenclature
                                                                                                                                                                                                                                                                                                                                                      • 3482 Testing with Uncorrelated Excitations
                                                                                                                                                                                                                                                                                                                                                      • 3483 Symmetrical Rectilinear Testing
                                                                                                                                                                                                                                                                                                                                                      • 3484 Geometry vs Dynamics
                                                                                                                                                                                                                                                                                                                                                      • 3485 Some Limitations
                                                                                                                                                                                                                                                                                                                                                      • 3486 Testing Black Boxes
                                                                                                                                                                                                                                                                                                                                                      • 3487 Phasing of Excitations
                                                                                                                                                                                                                                                                                                                                                      • 3488 Testing a Gray or White Box
                                                                                                                                                                                                                                                                                                                                                      • 3489 Overtesting in Multitest Sequences
                                                                                                                                                                                                                                                                                                                                                          • 35 Some Practical Information
                                                                                                                                                                                                                                                                                                                                                            • 351 Random Vibration Test Example
                                                                                                                                                                                                                                                                                                                                                            • 352 Vibration Shakers and Control Systems
                                                                                                                                                                                                                                                                                                                                                              • Bibliography
                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                  • 53191ch4
                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                    • Chapter 4 Experimental Modal Analysis
                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                      • 41 Introduction
                                                                                                                                                                                                                                                                                                                                                                      • 42 Frequency-Domain Formulation
                                                                                                                                                                                                                                                                                                                                                                        • 421 Transfer-Function Matrix
                                                                                                                                                                                                                                                                                                                                                                        • 422 Principle of Reciprocity
                                                                                                                                                                                                                                                                                                                                                                          • 43 Experimental Model Development
                                                                                                                                                                                                                                                                                                                                                                            • 431 Extraction of the Time-Domain Model
                                                                                                                                                                                                                                                                                                                                                                              • 44 Curve Fitting of Transfer Functions
                                                                                                                                                                                                                                                                                                                                                                                • 441 Problem Identification
                                                                                                                                                                                                                                                                                                                                                                                • 442 Single- and Multi-Degree-of-Freedom Techniques
                                                                                                                                                                                                                                                                                                                                                                                • 443 Single-Degree-of-Freedom Parameter Extraction in the Frequency Domain
                                                                                                                                                                                                                                                                                                                                                                                  • 4431 Circle-Fit Method
                                                                                                                                                                                                                                                                                                                                                                                    • Case of Viscous Damping
                                                                                                                                                                                                                                                                                                                                                                                    • Case of Hysteretic Damping
                                                                                                                                                                                                                                                                                                                                                                                      • 4432 Peak-Picking Method
                                                                                                                                                                                                                                                                                                                                                                                        • 444 Multi-Degree of Freedom Curve Fitting
                                                                                                                                                                                                                                                                                                                                                                                          • 4441 Formulation of the Method
                                                                                                                                                                                                                                                                                                                                                                                            • 445 A Comment on Static Modes and Rigid-Body Modes
                                                                                                                                                                                                                                                                                                                                                                                            • 446 Residue Extraction
                                                                                                                                                                                                                                                                                                                                                                                              • 45 Laboratory Experiments
                                                                                                                                                                                                                                                                                                                                                                                                • 451 Lumped-Parameter System
                                                                                                                                                                                                                                                                                                                                                                                                  • 4511 Frequency-Domain Test
                                                                                                                                                                                                                                                                                                                                                                                                  • 4512 Time-Domain Tests
                                                                                                                                                                                                                                                                                                                                                                                                    • 452 Distributed-Parameter System
                                                                                                                                                                                                                                                                                                                                                                                                      • 46 Commercial EMA Systems
                                                                                                                                                                                                                                                                                                                                                                                                        • 461 System Configuration
                                                                                                                                                                                                                                                                                                                                                                                                          • 4611 FFT Analysis Options
                                                                                                                                                                                                                                                                                                                                                                                                          • 4612 Modal Analysis Components
                                                                                                                                                                                                                                                                                                                                                                                                              • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                  • 53191ch5
                                                                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                    • Chapter 5 Mechanical Shock
                                                                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                      • 51 Definitions
                                                                                                                                                                                                                                                                                                                                                                                                                        • 511 Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 512 Simple (or Perfect) Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 513 Half-Sine Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 514 Versed-Sine (or Haversine) Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 515 Terminal Peak Sawtooth Shock or Final Peak Sawtooth Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 516 Rectangular Shock
                                                                                                                                                                                                                                                                                                                                                                                                                          • 5161 Trapezoidal Shock
                                                                                                                                                                                                                                                                                                                                                                                                                              • 52 Description in the Time Domain
                                                                                                                                                                                                                                                                                                                                                                                                                              • 53 Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                • 531 Need
                                                                                                                                                                                                                                                                                                                                                                                                                                • 532 Shock Response Spectrum Definition
                                                                                                                                                                                                                                                                                                                                                                                                                                • 533 Response of a Linear One-Degree-of-Freedom System
                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5331 Shock Defined by a Force
                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5332 Shock Defined by an Acceleration
                                                                                                                                                                                                                                                                                                                                                                                                                                    • 534 Definitions
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5341 Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5342 Absolute Acceleration Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5343 Relative Displacement Shock Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5344 Primary Positive Shock Response Spectrum or Initial Positive Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5345 Primary (or Initial) Negative Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5346 Secondary (or Residual) Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5347 Positive (or Maximum Positive) Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5348 Negative (or Maximum Negative) Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5349 Maximax Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53410 Choice of Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                        • 535 Standardized Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5351 Definition
                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5352 Standardized Shock Response Spectra of Simple Shocks
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53521 Half-Sine Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53522 Versed Sine Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53523 Terminal Peak Sawtooth Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53524 Rectangular Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53525 Trapezoidal Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 536 Choice of Damping
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 537 Shock Response Spectra Domains
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 538 Algorithms for Calculation of the Shock Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 539 Choice of the Digitization Frequency of the Signal
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5310 Use of Shock Response Spectra for the Study of Systems with Several Degrees of Freedom
                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 54 Pyroshocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 55 Use of Shock Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 551 Severity Comparison of Several Shocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 552 Test Specification Development from Real Environment Data
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5521 Synthesis of Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5522 Nature of the Specification
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5523 Choice of Shape
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5524 Amplitude
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5525 Duration
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5526 Difficulties
                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 56 Standards
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 561 Types of Standards
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 562 Installation Conditions of Test Item
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 563 Uncertainty Factor
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 564 Bump Test
                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 57 Damage Boundary Curve
                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 571 Definition
                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 572 Analysis of Test Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 58 Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 581 Main Types
                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 582 Impact Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5821 Universal Shock-Test Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 58211 Impact Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 58212 Impulse Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 583 Shock Simulators (Programmers)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5831 Half-Sine Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58311 Shock Duration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58312 Impact Velocity
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58313 Maximum Deformation of the Shock Simulator (Programmer)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58314 Shock Amplitude
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58315 Characteristics of the Target
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5832 Terminal Peak Sawtooth Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5833 Rectangular Pulse ndash Trapezoidal Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5834 Universal Shock Simulator (Programmer)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 58341 Generating a Half-Sine Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 58342 Generating a Terminal Peak Sawtooth Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 58343 Trapezoidal Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 584 Limitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5841 Limitations of the Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5842 Limitations of Shock Simulators
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 585 Pneumatic Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 586 High Impact Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5861 Lightweight High Impact Shock Machine
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5862 Medium Weight High Impact Shock Machine
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 587 Specific Test Facilities
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 59 Generation of Shock Using Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 591 Principle Behind the Generation of a Simple Shape Signal versus Time
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 592 Main Advantages
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 593 Pre- and Postshocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5931 Requirements
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5932 Solutions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 59321 Optimized Pre- and Postpulses
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5933 Incidence on the Shock Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 594 Limitations of Electrodynamic Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5941 Mechanical Limitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 59411 Abacuses
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5942 Electronic Limitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 595 The Use of Electrohydraulic Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 510 Control by a Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 5101 Principle
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 5102 Principal Shapes of Elementary Signals
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 51021 Decaying Sinusoid
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 51022 ZERD Function
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 51023 WAVSIN Waveform
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 5103 Comparison of WAVSIN SHOC Waveforms and Decaying Sinusoid
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 5104 Criticism of Control by a Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 511 Pyrotechnic Shock Simulation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5111 Simulation Using Pyrotechnic Facilities
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5112 Simulation Using Metal-to-Metal Impact
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5113 Simulation Using Electrodynamic Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5114 Simulation Using Conventional Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53191ch6
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Chapter 6 Machine Condition Monitoring and Fault Diagnostics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 61 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 62 Machinery Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 621 Causes of Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 622 Types of Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 623 Frequency of Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 63 Basic Maintenance Strategies
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 631 Run-to-Failure (Breakdown) Maintenance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 632 Scheduled (Preventative) Maintenance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 633 Condition-Based (Predictive Proactive Reliability Centered On-Condition) Maintenance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 64 Factors Which Influence Maintenance Strategy
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 65 Machine Condition Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 651 Periodic Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 652 Continuous Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 66 Transducer Selection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 661 Noncontact Displacement Transducers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 662 Velocity Transducers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 663 Acceleration Transducers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 67 Transducer Location
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 68 Recording and Analysis Instrumentation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 681 Vibration Meters
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 682 Data Collectors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 683 Frequency-Domain Analyzers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 684 Time-Domain Instruments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 685 Tracking Analyzers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 69 Display Formats and Analysis Tools
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 691 Time Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6911 Time-Waveform Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6912 Time-Waveform Indices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6913 Time-Synchronous Averaging
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6914 Negative Averaging
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6915 Orbits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6916 Probability Density Functions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6917 Probability Density Moments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 692 Frequency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6921 Band-Pass Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6922 Shock Pulse (Spike Energy)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6923 Enveloped Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6924 Signature Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6925 Cascades (Waterfall Plots)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6926 Masks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6927 Frequency-Domain Indices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 693 Modal Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 694 Quefrency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 610 Fault Detection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 6101 Standards
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61011 Standards Based on Machinery Type
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61012 Standards Based on Vibration Severity
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 6102 Acceptance Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 61021 Statistical Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 6103 Frequency-Domain Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61031 Limited Band Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61032 Constant Bandwidth Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61033 Constant Percentage Bandwidth Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 611 Fault Diagnostics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 6111 Forcing Functions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61111 Unbalance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61112 Misalignment
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61113 Mechanical Looseness
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61114 Soft Foot
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61115 Rubs
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61116 Resonances
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61117 Oil Whirl
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61118 Oil Whip
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61119 Structural Vibrations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 611110 Foundation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 6112 Specific Machine Components
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 61121 Damaged or Worn Rolling-Element Bearings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 61122 Damaged or Worn Gears
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 6113 Specific Machine Types
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61131 Pumps
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61132 Fans
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61133 Electric Motors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61134 Steam and Gas Turbines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61135 Compressors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61136 Reciprocating Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 6114 Advanced Fault Diagnostic Techniques
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 53191ch7
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • Chapter 7 Vibration-Based Tool Condition Monitoring Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 71 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 72 Mechanics of Turning
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 721 General Terms
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 722 Chatter Vibrations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 723 Tool Wear
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7231 Tool Failure Mechanisms
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7232 Tool Failure Modes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7233 Tool Wear Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7234 Tool Wear Stages
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 73 Vibration Signal Recording
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 731 Direct and Indirect Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 732 Sensor Requirements for Tool Wear Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 733 Force Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7331 Direct Measurement Dynamometers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7332 Indirect Force Sensors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7333 Piezoelectric Strain Sensors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7334 Resistance Strain Gauges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7335 Customized Force Sensors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 734 Acceleration Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 735 Acoustic Emission Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 736 Sensor Comparisons
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 74 Signal Processing for Sensor-Based Tool Condition Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 741 Feature Extraction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7411 Time Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7412 Frequency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7413 Statistical Processing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7414 TimendashFrequency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 742 Feature Selection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 75 Wear ModelDecision-Making for Sensor-Based Tool Condition Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 751 Trending Threshold
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 752 Neural Networks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7521 Unsupervised Networks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7522 Supervised Networks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 753 Fuzzy Logic
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 754 Other Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 76 Conclusion
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53191ch8
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Chapter 8 Fault Diagnosis of Helicopter Gearboxes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 81 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 82 Abnormality Scaling
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 83 The Structure-Based Connectionist Network
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 84 Sensor Location Selection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 841 Coverage Index
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 842 Overlap Index
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 843 Monitoring Effectiveness
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 85 A Case Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 851 Structural and Featural Influences
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 852 Evaluation of Influences
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 853 Fault Detection Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 854 Fault Diagnostic Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 8541 Faulty Subsystem Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 8542 Faulty Component Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 855 Sensor Location Evaluation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 856 Sensor Location Validation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 86 Conclusion
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 53191ch9
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Chapter 9 Vibration Suppression and Monitoring in Precision Motion Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 91 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 92 Mechanical Design to Minimize Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 921 Stability and Static Determinacy of Machine Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 922 Two-Dimensional Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 923 Three-Dimensional Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 93 Adaptive Notch Filter
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 931 Fast Fourier Transform
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 932 Simulation and Experiments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 94 Real-Time Vibration Analyzer
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 941 Learning Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 942 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 943 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 944 Experiments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 9441 Input Variables mdash the Evaluation Criteria
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 94411 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 94412 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 9442 Evaluation Rules
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 94421 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 94422 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 9443 Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 94431 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 94432 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 95 Practical Insights and Case Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 96 Conclusions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 53191ch10
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Chapter 10 Vibration and Shock Problems of Civil Engineering Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 101 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 102 Earthquake-Induced Vibration of Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1021 Seismicity and Ground Motions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1022 Influence of Local Site Conditions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1023 Response of Structures to Ground Motions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1024 Dynamic Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10241 Equations of Motion for Linear Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10242 Equations of Motion for Linear Multiple-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1025 Earthquake Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10251 Elastic Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10252 Smoothed Design Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10253 Ductility-Modified Response Spectrum Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1026 Design Philosophy and the Code Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10261 Performance-Based Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1027 Analysis Options for Earthquake Effects
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10271 Dynamic Time History Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10272 Response Spectrum Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 102721 Response Spectrum Analysis of Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 102722 Response Spectrum Analysis of Multi-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10273 Equivalent Static Analysis (Force-Based Approach)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10274 Displacement-Based Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1028 SoilndashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1029 Active and Passive Control Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 10210 Worked Examples
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 103 Dynamic Effects of Wind Loading on Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1031 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1032 Wind Speed
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1033 Design Structures for Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10331 Types of Wind Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10332 Design Criteria
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10333 Static Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1034 Along and Across-Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10341 Along-Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10342 Across-Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1035 Wind Tunnel Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1036 Comfort Criteria Human Response to Building Motion
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1037 Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1038 Comparison with Earthquake Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 104 Vibrations Due to Fluid ndashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1041 Added Mass and Inertial Coupling
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1042 Wave-Induced Vibration of Structure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 105 Blast Loading and Blast Effects on Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1051 Explosions and Blast Phenomenon
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1052 Explosive Air-Blast Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10521 Blast Wave Scaling Laws
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10522 Prediction of Blast Pressure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1053 Gas Explosion Loading and Effect of Internal Explosions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1054 Structural Response to Blast Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10541 Elastic Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10542 Elasto-Plastic Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1055 Material Behaviors at High Strain Rate
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10551 Dynamic Properties of Concrete under High Strain Rates
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10552 Dynamic Properties of Reinforcing Steel under High Strain Rates
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1056 Failure Modes of Blast-Loaded Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10561 Global Structural Behavior
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10562 Localized Structural Behavior
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10563 PressurendashImpulse ( PndashI ) Diagrams
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1057 Blast WavendashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1058 Effect of Ground Shocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10581 Loads from Air-Induced Ground Shock
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10582 Loads from Direct Ground Shock
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1059 Technical Design Manuals for Blast-Resistant Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 10510 Computer Programs for Blast and Shock Effects
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 106 Impact Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1061 Structural Impact between Two Bodies mdash Hard Impact and Soft Impact
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1062 Example mdash Aircraft Impact
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 107 Floor Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1071 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1072 Types of Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10721 Walking
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10722 Rhythmic Activities
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10723 Mechanical Equipment
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10724 Analysis Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1073 Natural Frequency of Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10731 Computing the Natural Frequency
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10732 Computing Deflection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10733 Damping
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10734 Resonance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1074 Vibration Caused by Walking
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10741 Minimum Natural Frequency
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1075 Design for Rhythmic Excitation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10751 Harmonics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10752 Minimum Natural Frequency
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1076 Example mdash Vibration Analysis of a Reinforced Concrete Floor
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 53191ch11
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Chapter 11 Seismic Base Isolation and Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 111 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1111 From Ductility Design to Base Isolation and Control Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1112 The Importance of Reducing Seismic Input and Response
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 112 Seismic Base Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1121 Historical Development of Base Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1122 Basic Principle
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1123 Issues in Seismic Base Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11231 Performance Criteria
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11232 Type of Structure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11233 Site Characteristics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11234 Retrofit Issues
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11235 Design of Building Services
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11236 Expected Life of Isolator
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1124 Seismic Isolation Devices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11241 Laminated Rubber Bearings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11242 Lead Rubber Bearing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11243 Friction-Based Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11244 Other Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1125 Design of Isolation Devices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11251 High-Damping Rubber Bearing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112511 Stability against Buckling
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112512 Stability against Roll Out
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11252 Lead Rubber Bearings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112521 Design of Lead Plug
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112522 Design of Laminated Rubber Bearing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11253 Design of Friction Pendulum System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1126 Verification of Properties of Isolation Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11261 Tests for Isolation Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 112611 System Characterization Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 112612 Prototype Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 112613 Quality Control Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11262 Uniform Building Code Recommendations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112621 Units Dependent on Loading Rates
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112622 Units Dependent on Bilateral Load
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112623 System Adequacy
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1127 Analysis of Base-Isolated Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11271 Modeling of a Superstructure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11272 Modeling of Isolation System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11273 Static Analysis Procedure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11274 Dynamic Analysis Procedure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 112741 Response Spectrum Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 112742 Time-History Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11275 Software for Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1128 Experimental Methods for Isolated Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1129 Implementation of Seismic Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11291 New Construction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112911 Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112912 Bridges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11292 Seismic Retrofit
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112921 Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112922 Bridges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11293 Other Implementations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 11210 Performance during Past Earthquakes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 112101 Performance of Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 112102 Performance of Bridges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 113 Seismic Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1131 Historical Development of Seismic Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1132 Basic Principles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11321 Passive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11322 Active Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11323 Semiactive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11324 Hybrid Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11325 Categorization of Basic Principles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1133 Important Issues in Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11331 SoilndashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11332 DevicendashStructure Interaction and Time Delay
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11333 Design Guidelines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1134 Vibration-Control Devices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11341 Passive Control Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113411 Metallic Yielding Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113412 Friction Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113413 Viscoelastic Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113414 Viscous Fluid Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113415 Tuned Mass Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11342 Active Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113421 Electromagnetic Actuator
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113422 Hydraulic Actuators
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11343 Semiactive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113431 Variable-Orifice Hydraulic Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113432 Controllable Fluid Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113433 Controllable Friction Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11344 Hybrid Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1135 Control Algorithm
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11351 Active Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11352 Semiactive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113521 Common Control Schemes for Controllable Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113522 Special Control Schemes for Controllable Damper
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1136 Experimental Performance Verification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11361 Shaking Table Tests of a Flexible Structural Model with TMD AMD and ATMD
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11362 Substructure Hybrid Test
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113621 Hybrid Tests Using Hydraulic Actuator
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113622 Hybrid Tests Using Shaking Table
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113623 Hybrid Tests Using Inertia-Force-Driven Loading System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1137 Implementations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11371 Semiactive Control of Full-Scale Structures Using Variable Joint Damper System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113711 Background of Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113712 Test System Set Up
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113713 Control Algorithm
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113714 Test Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11372 Application of Structural Control Technologies to Seismic Retrofit of a Cable-Stayed Bridge
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113721 Background of Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113722 Basic Concept of Seismic Retrofit
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113723 Modal Shape Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113724 Time-History Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113725 Soil ndash Structure Interaction Effect
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113726 Semiactive Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53191ch12
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Chapter 12 Seismic Random Vibration of Long-Span Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 121 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1211 Basic Concepts of Random Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12111 Stationary Random Process
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12112 Nonstationary Random Process
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1212 Three Methods for Structural Seismic Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12121 Response Spectrum Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12122 Time-History Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12123 Random Vibration Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 121231 Davenport Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 121232 Vanmarcke Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 12124 Comparisons of the Three Seismic-Analysis Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 122 Seismic Random-Excitation Fields
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1221 Power Spectral Density of Spatially Varying Ground Acceleration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1222 Several Coherence Models
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12221 FengndashHu Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12222 Harichandran ndashVanmarcke Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12223 LohndashYeh Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12224 OliveirandashHaondashPenzien Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12225 LucondashWong Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12226 QundashWangndashWang Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1223 Generation of Ground Acceleration Power Spectral Density Curves from Acceleration Response Spectrum Curves
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12231 Kaul Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12232 Iteration Scheme
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1224 Seismic Equations of Motion of Long-Span Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1225 Seismic Waves and Their Geometrical Expressions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 123 Pseudoexcitation Method for Structural Random Vibration Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1231 Structures Subjected to Stationary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12311 Single Stationary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12312 Multiple Stationary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1232 Structures Subjected to Nonstationary Random Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12321 Structures Subjected to Uniformly Modulated Evolutionary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 123211 Single Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 123212 Multiple Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12322 Structures Subjected to Nonuniformly Modulated Evolutionary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 123221 Single Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 123222 Multiple Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1233 Precise Integration Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12331 Precise Integration of Exponential Matrices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12332 Particular Solutions and Precise Integration Formulas for Various Forms of Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 123321 Linear Loading Form (HPD-L Form)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 123322 Sinusoidal Loading Form (HPD-S Form)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 123323 Exponentially Decaying Sinusoidal Loading Form (HPD-E Form)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 124 Long-Span Structures Subjected to Stationary Random Ground Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1241 The Solution of Equations of Motion Using the Pseudoexcitation Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1242 Numerical Comparisons with Other Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12421 Song-Hua-Jiang Suspension Bridge
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 124211 All Supports Move Uniformly
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 124212 Wave Passage Effect Is Taken into Account
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 124213 Wave-Passage Effect and Incoherence Effect Are Jointly Taken into Account
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 12422 San Joaquin Concrete Bridge
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 125 Long-Span Structures Subjected to Nonstationary Random Ground Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1251 Modulation Functions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1252 The Formulas for Nonstationary Multiexcitation Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1253 Expected Extreme Values of Nonstationary Random Processes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1254 Numerical Comparisons with the Corresponding Stationary Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 126 Conclusions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Related Titles
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                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Chapter 13 Seismic Qualification of Equipment
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 131 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 132 Distribution Qualification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1321 Drive-Signal Generation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1322 Distribution Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1323 Test Procedures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 133 Seismic Qualification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1331 Stages of Seismic Qualification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1332 Test Preliminaries
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1333 Single-Frequency Testing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1334 Multifrequency Testing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1335 Generation of RRS Specifications
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Related Titles
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                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Chapter 14 Human Response to Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 141 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 142 Vibration Excitations on Humans
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1421 Excitation Characteristics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 143 Human Response to Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1431 Vibration Perception
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1432 Frequency Weighting Curve
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1433 Iso-Perception Curves
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1434 Detection Threshold Curve
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 144 Regulation of Human Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1441 Acceptable Vibration Levels in Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1442 Whole-Body Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1443 HandndashArm Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
Page 22: Vibration Monitoring, Testing, and Instrumentationpreview.kingborn.net › 646000 › d1a74678d91943e5ba1d5e... · The MEMS Handbook, Second Edition MEMS: Introduction and Fundamentals

place weights In this manner the magnitude of

the eccentric mass can be varied to achieve various

force capabilities The rods are driven by a

variable-speed electric motor through a gear

mechanism that usually provides several speed

ratios A speed ratio is selected depending on the

required test-frequency range The whole system is

symmetrically supported on a carriage that is

directly connected to the test table The test object

is mounted on the test table The preferred

mounting configuration is horizontal so that the

excitation force is applied to the test object in a

horizontal direction In this configuration there

are no variable gravity moments (weight pounddistance to center of gravity) acting on the drive

mechanism Figure 17 shows the vertical con-

figuration In dynamic testing of large structures

the carriage can be mounted directly on the

structure at a location where the excitation force

should be applied By incorporating two pairs of

counter-rotating masses it is possible to generate

test moments as well as test forces

FIGURE 15 A typical hydraulic shaker arrangement (a) schematic diagram (b) operational block diagram

m m

2mw2r cos wt

wtw w

wt

FIGURE 16 Principle of operation of a counter-

rotating-mass inertial shaker

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copy 2007 by Taylor amp Francis Group LLC

Reaction-type shakers driven by inertia are widely used for the prototype testing of civil engineering

structures Their first application dates back to 1935 Inertial shakers are capable of producing

intermediate excitation forces The force generated is limited by the strength of the carriage frame The

frequency range of operation and the maximum velocity and acceleration capabilities are also

intermediate for inertial shakers whereas the maximum displacement capability is typically low A major

limitation of inertial shakers is that their excitation force is exclusively sinusoidal and that the force

amplitude is directly proportional to the square of the excitation frequency As a result complex and

random excitation testing constant-force testing (for example transmissibility tests and constant-force

sine-sweep tests) and flexibility to vary the force amplitude or the displacement amplitude during a test

are not generally feasible with this type of shakers Excitation frequency and amplitude can be varied

during testing however by incorporating a variable-speed drive for the motor The sinusoidal excitation

generated by inertial shakers is virtually undistorted which gives them an advantage over the other types

of shakers when used in sine-dwell and sine-sweep tests Small portable shakers with low-force capability

are available for use in on-site testing

1216 Electromagnetic Shakers

In electromagnetic shakers or ldquoelectrodynamic excitersrdquo the motion is generated using the principle of

operation of an electric motor Specifically the excitation force is produced when a variable excitation

signal (electrical) is passed through a moving coil placed in a magnetic field

The components of a commercial electromagnetic shaker are shown in Figure 18 A steady magnetic

field is generated by a stationary electromagnet that consists of field coils wound on a ferromagnetic base

that is rigidly attached to a protective shell structure The shaker head has a coil wound around it When

the excitation electrical signal is passed through this drive coil the shaker head which is supported on

flexure mounts will be set in motion The shaker head consists of the test table on which the test object

is mounted Shakers with interchangeable heads are available The choice of appropriate shaker head is

based on the geometry and mounting features of the test object The shaker head can be turned to

different angles by means of a swivel joint In this manner different directions of excitation (in biaxial

and triaxial testing) can be obtained

FIGURE 17 Sketch of a counter-rotating-mass inertial shaker

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copy 2007 by Taylor amp Francis Group LLC

122 Dynamics of Electromagnetic Shakers

Consider a single axis electromagnetic shaker (Figure 18) with a test object having a single natural

frequency of importance within the test frequency range The dynamic interactions between the shaker

and the test object give rise to two significant natural frequencies (and correspondingly two significant

resonances) These appear as peaks in the frequency response curve of the test setup Furthermore the

natural frequency (resonance) of the test package alone causes a ldquotroughrdquo or depression (antiresonance)

in the frequency response curve of the overall test setup To explain this characteristic consider the

dynamic model shown in Figure 19 The following mechanical parameters are defined for

Figure 19(a) m k and b are the mass stiffness and equivalent viscous damping constant respectively

of the test package and me ke and be are the corresponding parameters of the exciter (shaker) Also in

the equivalent electrical circuit of the shaker head as shown in Figure 19(b) the following electrical

parameters are defined Re and Le are the resistance and (leakage) inductance and kb is the back

electromotive force (back emf) of the linear motor Assuming that the gravitational forces are supported

FIGURE 18 Schematic sectional view of a typical electromagnetic shaker manufactured by Bruel and Kjaer

Denmark

Vibration Monitoring Testing and Instrumentation1-12

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by the static deflections of the flexible elements and that the displacements are measured from the static

equilibrium position we have the following system equations

Test object meuroy frac14 2kethy2 yeTHORN2 beth_y2 _yeTHORN eth119THORNShaker head me euroye frac14 fe thorn kethy2 yeTHORN thorn beth_y2 _yeTHORN2 key 2 be _ye eth120THORN

Electrical Lediedt

thorn Reie thorn kb _ye frac14 vethtTHORN eth121THORN

The electromagnetic force fe generated in the shaker head is a result of the interaction of the magnetic

field generated by the current ie with coil of the moving shaker head and the constant magnetic field

(stator) in which the head coil is located Here we have

fe frac14 kbie eth122THORNNote that v(t) is the voltage signal that is applied by the amplifier to the shaker coil ye is the displacement

of the shaker head and y is the displacement response of the test package

It is assumed that kb has consistent electrical and mechanical units (Vmsec and NA) Usually

the electrical time constant of the shaker is quite small compared with the primarily mechanical

time constants of the shaker and the test package In such cases the Ledie=dt term in Equation 121 may

be neglected Consequently the equations from Equation 119 through Equation 122 may be

expressed in the Laplace (frequency) domain with the Laplace variable s taking the place of the derivative

d=dt as

ethms2 thorn bsthorn kTHORNy frac14 ethbsthorn kTHORNye eth123THORN

FIGURE 19 Dynamic models of an electromagnetic shaker and a flexible test package (a) mechanical model

(b) electrical model

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frac12mes2 thorn ethbthorn beTHORNsthorn ethkthorn keTHORN ye frac14 ethbsthorn kTHORNy thorn kb

Rev2

k2bs

Reye eth124THORN

It follows that the transfer function of the shaker head motion with respect to the excitation voltage is

given by

yevfrac14 kb

Re

DethsTHORNDdethsTHORN eth125THORN

where DethsTHORN is the characteristic function of the primary dynamics of the test object

DethsTHORN frac14 ms2 thorn bsthorn k eth126THORN

and DdethsTHORN is the characteristic function of the primary dynamic interactions between the shaker and thetest object

DcethsTHORN frac14 mmes4 thorn frac12methbe thorn bthorn boTHORN thornmeb s

3 thorn frac12methke thorn kTHORN thornmekthorn bethbe thorn boTHORN s2thorn frac12bke thorn ethbe thorn boTHORNk sthorn kke

eth127THORN

where

bo frac14 k2bRe

eth128THORN

It is clear that under low damping conditions DdethsTHORN will produce two resonances as it is fourth order in sand similarly DethsTHORN will produce one antiresonance (trough) corresponding to the resonance of the testobject Note that in the frequency domain s frac14 jv and hence the frequency response function given by

Equation 125 is in fact

yevfrac14 kb

Rb

DethjvTHORNDdethjvTHORN eth129THORN

The magnitude of this frequency response function for a typical test system is sketched in Figure 110

Note that this curve is for the ldquoopen-looprdquo case where there is no feedback from the shaker controller

In practice the shaker controller will be able

to compensate for the resonances and anti-

resonances to some degree depending on its

effectiveness

The main advantages of electromagnetic

shakers are their high frequency range of

operation their high degree of operating flexi-

bility and the high level of accuracy of the

generated shaker motion Faithful reproduction

of complex excitations is possible because of the

advanced electronics and control systems used in

this type of shakers Electromagnetic shakers are

not suitable for heavy-duty applications (large test

objects) however High test-input accelerations

are possible at high frequencies when electromag-

netic shakers are used but their displacement and

velocity capabilities are limited to low or

intermediate values (see Table 11)

100

10

1 10 100Excitation Frequency (Hz)

Antiresonance

Resonance

Shak

erD

ispl

acem

entM

agni

tude

Resonance

1000

FIGURE 110 Frequency response curve of a typical

electromagnetic shaker with a test object

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1221 Transient Exciters

Other varieties of exciters are commonly used in

transient-type vibration testing In these tests

either an impulsive force or an initial excitation is

applied to the test object and the resulting

response is monitored The excitations and the

responses are ldquotransientrdquo in this case Hammer

test drop tests and pluck tests fall into this

category For example a hammer test may be

conducted by hitting the object with an instru-

mented hammer and then measuring the response

of the object The hammer has a force sensor at its

tip as sketched in Figure 111 A piezoelectric or

strain-gage type force sensor may be used More

sophisticated hammers have impedance heads in

place of force sensors An impedance head

measures force and acceleration simultaneously

The results of a hammer test will depend on many

factors for example the dynamics of the hammer

body how firmly the hammer is held during the

impact how quickly the impact is applied and

whether there are multiple impacts

13 Control System

The two primary functions of the shaker control system in vibration testing are (1) to guarantee that the

specified excitation is applied to the test object and (2) to ensure that the dynamic stability (motion

constraints) of the test setup is preserved An operational block diagram illustrating these control

functions is given in Figure 112 The reference input to the control system represents the desired

excitation force that should be applied to the test object In the absence of any control however the force

reaching the test object will be distorted primarily because of (1) dynamic interactions and

nonlinearities of the shaker the test table the mounting fixtures the auxiliary instruments and the test

object itself (2) noise and errors in the signal generator amplifiers filters and other equipment and (3)

external loads and disturbances acting on the test object and other components (for example external

restraints aerodynamic forces friction) To compensate for these distorting factors response

measurements (displacements velocities acceleration and so on) are made at various locations in the

test setup and are used to control the system dynamics In particular the responses of the shaker the test

table and the test object are measured These responses are used to compare the actual excitation felt by

FIGURE 111 An instrumented hammer used in bump

tests or hammer tests

ExcitationInput

(Reference)

Feedback Paths

DriveSignal

ShakerResponse

TestTable

TestObject

Test ObjectResponse

Test TableResponseExciter

(Shaker)(Ram)

Controllerand

Amplifier

FIGURE 112 Operational block diagram illustrating a general shaker control system

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the test object at the shaker interface with the desired (specified) input The drive signal to the shaker is

modified depending on the error that is present

Two types of control are commonly employed in shaker apparatus simple manual control and

complex automatic control Manual control normally consists of simple open-loop trial-and-error

methods of manual adjustments (or calibration) of the control equipment to obtain a desired dynamic

response The actual response is usually monitored (on an oscilloscope or frequency analyzer screen for

example) during manual-control operations The pretest adjustments in manual control can be very

time-consuming as a result the test object might be subjected to overtesting which could produce

cumulative damage is undesirable and could defeat the test purpose Furthermore the calibration

procedure for the experimental setup must be repeated for each new test object

The disadvantages ofmanual control suggest that automatic control is desirable in complex test schemes

in which high accuracy of testing is desired The first step of automatic control involves automatic

measurement of the system response using control sensors and transducers The measurement is then fed

back into the control system which instantaneously determines the best drive signal to actuate the shaker

in order to get the desired excitation This may be done by either analog or digital methods

Primitive control systems require an accurate mathematical description of the test object This

dependency of the control system on the knowledge of test-object dynamics is clearly undesirable

Performance of a good control system should not be considerably affected by the dynamic interactions

and nonlinearities of the test object or by the nature of the excitation Proper selection of feedback signals

and control-system components can reduce such effects and will make the system robust

In the response-spectrum method of vibration testing it is customary to use displacement control at

low frequencies velocity control at intermediate frequency and acceleration control at high frequencies

This necessitates feedback of displacement velocity and acceleration responses Generally however the

most important feedback is the velocity feedback In sine-sweep tests the shaker velocity must change

steadily over the frequency band of interest In particular the velocity control must be precise near the

resonances of the test object Velocity (speed) feedback has a stabilizing effect on the dynamics which is

desirable This effect is particularly useful in ensuring stability in motion when testing is done near

resonances of lightly damped test objects On the contrary displacement (position) feedback can have a

destabilizing effect on some systems particularly when high feedback gains are used

The controller usually consists of various instruments equipment and computation hardware and

software Often the functions of the data-acquisition and processing system overlap with those of the

controller to some extent As an example consider the digital-controller of vibration testing apparatus

First the responses are measured through sensors (and transducers) filtered and amplified

(conditioned) These data channels may be passed through a multiplexer whose purpose is to select

one data channel at a time for processing Most modern data acquisition hardware does not need a

separate multiplexer to handle multiple signals The analog data are converted into digital data using

analog-to-digital converters (ADCs) The resulting sampled data are stored on a disk or as a block data in

the computer memory The reference input signal (typically a signal recorded on an FM tape) is also

sampled (if it is not already in the digital form) using an ADC and fed into the computer Digital

processing is done on the reference signal and the response data with the objective of computing the

command signal to drive the shaker The digital command signal is converted into an analog signal using

a digital-to-analog converter (DAC) and amplified (conditioned) before it is used to drive the exciter

The nature of the control components depends to a large extent on the nature and objectives of the

particular test to be conducted Some of the basic components in a shaker controller are described in

the following subsections

131 Components of a Shaker Controller

1311 Compressor

A compressor circuit is incorporated in automatic excitation control devices to control the excitation-

input level automatically The level of control depends on the feedback signal from a control sensor and

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the specified (reference) excitation signal Usually the compressor circuit is included in the excitation-

signal generator (for example in a sine generator) The control by this means may be done on the basis of

a single-frequency component (eg the fundamental frequency)

1312 Equalizer (Spectrum Shaper)

Random-signal equalizers are used to shape the spectrum of a random signal in a desired manner In

essence and equalizer consists of a bank of narrow-band filters (for example 80 filters) in parallel over

the operating frequency range By passing the signal through each filter the spectral density (or the mean

square value) of the signal in that narrow frequency band (for example each one-third-octave band) is

determined This is compared with the desired spectral level and automatic adjustment is made in that

filter in case there is an error In some systems response-spectrum analysis is made in place of power

spectral density analysis In that case the equalizer consists of a bank of simple oscillators whose

resonant frequencies are distributed over the operating frequency range of the equalizer The feedback

signal is passed through each oscillator and the peak value of its output is determined This value is

compared with the desired response spectrum value at that frequency If there is an error automatic gain

adjustment is made in the appropriate excitation signal components

Random-noise equalizers are used in conjunction with random signal generators They receive

feedback signals from the control sensors In some digital control systems there are algorithms (software)

that are used to iteratively converge the spectrum of the excitation signal felt by the test object into the

desired spectrum

1313 Tracking Filter

Many vibration tests are based on single-frequency excitations In such cases the control functions

should be performed on the basis of the amplitudes of the fundamental-frequency component of the

signal A tracking filter is simply a frequency-tuned band-pass filter It automatically tunes the center

frequency of its very narrow-band-pass filter to the frequency of a carrier signal Then when a noisy

signal is passed through the tuned filter the output of the filter will be the required fundamental

frequency component in the signal Tracking filters also are useful in obtaining amplitudendashfrequency

plots using an XndashY plotter In such cases the frequency value comes from the signal generator (sweep

oscillator) which produces the carrier signal to the tracking filter The tracking filter then determines the

corresponding amplitude of a signal that is fed into it Most tracking filters have dual channels so that two

signals can be handled (tracked) simultaneously

1314 Excitation Controller (Amplitude Servo-Monitor)

An excitation controller is typically an integral part of the signal generator It can be set so that automatic

sweep between two frequency limits can be performed at a selected sweep rate (linear or logarithmic)

More advanced excitation controllers have the capability of an automatic switch-over between constant-

displacement constant-velocity and constant-acceleration excitation-input control at specified

frequencies over the sweep frequency interval Consequently integrator circuits should be present

within the excitation controller unit to determine velocities and displacements from acceleration signals

Sometimes integration is performed by a separate unit called a vibration meter This unit also offers

the operator the capability of selecting the desired level of each signal (acceleration velocity or

displacement) There is an automatic cut-off level for large displacement values that could result from

noise in acceleration signals A compressor is also a subcomponent of the excitation controller The

complete unit is sometimes known as an amplitude servo-monitor

132 Signal-Generating Equipment

Shakers are force-generating devices that are operated using drive (excitation) signals generated from a

source The excitation-signal source is known as the signal generator Three major types of signal

generators are used in vibration testing applications (1) oscillators (2) random-signal generators and

(3) storage devices In some units oscillators and random-signal generators are combined We shall

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copy 2007 by Taylor amp Francis Group LLC

discuss these two generators separately however because of their difference in function It also should be

noted that almost any digital signal (deterministic or random) can be generated by a digital computer

using a suitable computer program the signal eventually can be passed through a DAC to obtain

the corresponding analog signal These lsquodigitalrsquo signal generators along with analog sources such as

magnetic tape players (FM) are classified into the category of storage devices

The dynamic range of equipment is the ratio of the maximum and minimum output levels (expressed

in decibels) at which it is capable of operating without significant error This is an important specification

for many types of equipment particularly for signal-generating devices The output level of the signal

generator should be set to a value within its dynamic range

1321 Oscillators

Oscillators are essentially single-frequency generators Typically sine signals are generated but other

waveforms (such as rectangular and triangular pulses) are also available in most oscillators Normally

an oscillator has two modes of operation (1) sweeping up and down between two frequency limits and

(2) dwelling at a specified frequency In the sweep operation the sweep rate should be specified This can

be done either on a linear scale (Hzmin) or on a logarithmic scale (octavesmin) In the dwell operation

the frequency points (or intervals) should be specified In either case a desired signal level can be chosen

using the gain-control knob An oscillator that is operated exclusively in the sweep mode is called a sweep

oscillator

The early generation of oscillators employed variable inductor-capacitor types of electronic circuits to

generate signals oscillating at a desired frequency The oscillator is tuned to the required frequency by

varying the capacitance or inductance parameters A DC voltage is applied to energize the capacitor

and to obtain the desired oscillating voltage signal which subsequently is amplified and conditioned

Modern oscillators use operational amplifier circuits along with resistor capacitor and semiconductor

(SC) elements Also common are crystal (quartz) parallel-resonance oscillators used to generate voltage

signals accurately at a fixed frequency The circuit is activated using a DC-voltage source Other

frequencies of interest are obtained by passing this high-frequency signal through a frequency converter

The signal is then conditioned (amplified and filtered) Required shaping (for example rectangular

pulse) is obtained using a shape circuit Finally the required signal level is obtained by passing the

resulting signal through a variable-gain amplifier A block diagram of an oscillator illustrating various

stages in the generation of a periodic signal is given in Figure 113

A typical oscillator offers a choice of several (typically six) linear and logarithmic frequency ranges and

a sizable level of control capability (for example 80 dB) Upper and lower frequency limits in a sweep can

be preset on the front panel to any of the available frequency ranges Sweep-rate settings are continuously

DC Voltage

Oscillator

FrequencySpecification

FrequencyConverter

FilterAmplifier

ShaperPeriodicSignal

FrequencyCounter

Fixed-FrequencySignal

Variable-GainOutput

Amplifier

SignalSpecification

LevelSpecification

FIGURE 113 Block diagram of an oscillator-type signal generator

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copy 2007 by Taylor amp Francis Group LLC

  • 53191fm
    • Vibration Monitoring Testing and Instrumentation
      • Preface
      • Acknowledgments
      • Editor-in-Chief
      • Contributors
      • Contents
      • Related Titles
          • 53191ch1
            • Table of Contents
            • Chapter 1 Vibration Instrumentation
              • Summary
              • 11 Introduction
              • 12 Vibration Exciters
                • 121 Shaker Selection
                  • 1211 Force Rating
                  • 1212 Power Rating
                  • 1213 Stroke Rating
                  • 1214 Hydraulic Shakers
                  • 1215 Inertial Shakers
                  • 1216 Electromagnetic Shakers
                    • 122 Dynamics of Electromagnetic Shakers
                      • 1221 Transient Exciters
                          • 13 Control System
                            • 131 Components of a Shaker Controller
                              • 1311 Compressor
                              • 1312 Equalizer (Spectrum Shaper)
                              • 1313 Tracking Filter
                              • 1314 Excitation Controller (Amplitude Servo-Monitor)
                                • 132 Signal-Generating Equipment
                                  • 1321 Oscillators
                                  • 1322 Random Signal Generators
                                  • 1323 Tape Players
                                  • 1324 Data Processing
                                      • 14 Performance Specification
                                        • 141 Parameters for Performance Specification
                                          • 1411 Time-Domain Specifications
                                          • 1412 Frequency-Domain Specifications
                                            • 142 Linearity
                                            • 143 Instrument Ratings
                                              • 1431 Rating Parameters
                                                • 144 Accuracy and Precision
                                                  • 15 Motion Sensors and Transducers
                                                    • 151 Potentiometer
                                                      • 1511 Potentiometer Resolution
                                                      • 1512 Optical Potentiometer
                                                        • 152 Variable-Inductance Transducers
                                                          • 1521 Mutual-Induction Transducers
                                                          • 1522 Linear-Variable Differential Transformer
                                                          • 1523 Signal Conditioning
                                                            • 153 Mutual-Induction Proximity Sensor
                                                            • 154 Selfinduction Transducers
                                                            • 155 Permanent-Magnet Transducers
                                                            • 156 Alternating Current Permanent-Magnet Tachometer
                                                            • 157 Alternating Current Induction Tachometer
                                                            • 158 Eddy Current Transducers
                                                            • 159 Variable-Capacitance Transducers
                                                              • 1591 Capacitive Displacement Sensors
                                                              • 1592 Capacitive Angular Velocity Sensor
                                                              • 1593 Capacitance Bridge Circuit
                                                                • 1510 Piezoelectric Transducers
                                                                  • 15101 Sensitivity
                                                                  • 15102 Piezoelectric Accelerometer
                                                                  • 15103 Charge Amplifier
                                                                      • 16 Torque Force and Other Sensors
                                                                        • 161 Strain Gage Sensors
                                                                          • 1611 Equations for Strain Gage Measurements
                                                                          • 1612 Bridge Sensitivity
                                                                          • 1613 The Bridge Constant
                                                                          • 1614 The Calibration Constant
                                                                          • 1615 Data Acquisition
                                                                          • 1616 Accuracy Considerations
                                                                          • 1617 Semiconductor Strain Gages
                                                                          • 1618 Force and Torque Sensors
                                                                          • 1619 Strain Gage Torque Sensors
                                                                          • 16110 Deflection Torque Sensors
                                                                          • 16111 Variable-Reluctance Torque Sensor
                                                                          • 16112 Reaction Torque Sensors
                                                                            • 162 Miscellaneous Sensors
                                                                              • 1621 Stroboscope
                                                                              • 1622 Fiber Optic Sensors and Lasers
                                                                              • 1623 Fiber-Optic Gyroscope
                                                                              • 1624 Laser Doppler Interferometer
                                                                              • 1625 Ultrasonic Sensors
                                                                              • 1626 Gyroscopic Sensors
                                                                                  • References
                                                                                  • Appendix 1A Virtual Instrumentation for Data Acquisition Analysis and Presentation
                                                                                    • Summary
                                                                                    • List of Abbreviations
                                                                                    • 1A1 Dynamic Signals
                                                                                      • 1A11 Acquiring and Simulating Dynamic Signals
                                                                                        • 1A111 Aliasing
                                                                                        • 1A112 Time Continuity
                                                                                            • 1A2 Measurement Configuration Considerations
                                                                                              • 1A21 Input Signal Considerations
                                                                                                • 1A211 Input Pseudodifferential and Differential Configuration
                                                                                                • 1A212 Gain
                                                                                                • 1A213 Input Coupling
                                                                                                • 1A214 Integrated Electronic Piezoelectric Excitation
                                                                                                • 1A215 Nyquist Frequency and Bandwidth
                                                                                                • 1A216 Analog-to-Digital Conversion
                                                                                                • 1A217 Antialias Filters
                                                                                                • 1A218 Input Filter Delay
                                                                                                • 1A219 Overload Detection
                                                                                                  • 1A22 Output Signal Considerations
                                                                                                    • 1A221 Output Pseudodifferential and Differential Configuration
                                                                                                    • 1A222 Attenuation
                                                                                                    • 1A223 Digital-to-Analog Conversion
                                                                                                    • 1A224 Anti-imaging and Interpolation Filters
                                                                                                    • 1A225 Output Filter Delay
                                                                                                        • 1A3 Scaling and Calibration
                                                                                                          • 1A31 Scaling to Engineering Units
                                                                                                          • 1A32 Performing System Calibration
                                                                                                            • 1A321 Propagation Delay Calibration
                                                                                                                • 1A4 Limit Testing Analysis
                                                                                                                  • 1A41 Limit Testing Overview
                                                                                                                  • 1A42 Using the SVT Limit Testing VI
                                                                                                                    • 1A5 Integration
                                                                                                                      • 1A51 Introduction to Integration
                                                                                                                      • 1A52 Implementing Integration
                                                                                                                        • 1A521 Challenges when Integrating Vibration Data
                                                                                                                          • 1A53 Time-Domain Integration
                                                                                                                            • 1A531 Single-Shot Acquisition and Integration
                                                                                                                            • 1A532 Continuous Acquisition and Integration
                                                                                                                              • 1A54 Frequency-Domain Integration
                                                                                                                                • 1A6 Vibration-Level Measurements
                                                                                                                                  • 1A61 Measuring the Root Mean Square Level
                                                                                                                                    • 1A611 Single-Shot Buffered Acquisition
                                                                                                                                    • 1A612 Continuous Signal Acquisition
                                                                                                                                      • 1A62 Performing a Running RMS Level Measurement
                                                                                                                                      • 1A63 Computing the Peak Level
                                                                                                                                      • 1A64 Computing the Crest Factor
                                                                                                                                        • 1A7 Frequency Analysis
                                                                                                                                          • 1A71 FFT Fundamentals
                                                                                                                                            • 1A711 Number of Samples
                                                                                                                                            • 1A712 Frequency Resolution
                                                                                                                                            • 1A713 Maximum Resolvable Frequency
                                                                                                                                            • 1A714 Minimum Resolvable Frequency
                                                                                                                                            • 1A715 Number of Spectral Lines
                                                                                                                                            • 1A716 Relationship between Time-Domain and Frequency-Domain Specifications and Parameters
                                                                                                                                              • 1A72 Increasing Frequency Resolution
                                                                                                                                                • 1A721 Zoom FFT Analysis
                                                                                                                                                • 1A722 Frequency Resolution of the Zoom FFT VIs
                                                                                                                                                • 1A723 Zoom Measurement
                                                                                                                                                • 1A724 Zoom Settings
                                                                                                                                                • 1A725 Subset Analysis
                                                                                                                                                    • 1A8 Transient Analysis
                                                                                                                                                      • 1A81 Transient Analysis with the Sound and Vibration Toolkit
                                                                                                                                                      • 1A82 Performing an STFT vs Time
                                                                                                                                                        • 1A821 Selecting the FFT Block Size
                                                                                                                                                        • 1A822 Overlapping
                                                                                                                                                        • 1A823 Using the SVT STFT vs Time VI
                                                                                                                                                          • 1A83 Performing an STFT vs Rotational Speed
                                                                                                                                                            • 1A831 Converting the Pulse Train to Rotational Speed
                                                                                                                                                            • 1A832 STFT vs RPM
                                                                                                                                                              • 1A84 Measuring a Shock Response Spectrum
                                                                                                                                                                • 1A9 Waterfall Display
                                                                                                                                                                  • 1A91 Using the Display VIs
                                                                                                                                                                    • 1A911 Initializing the Display
                                                                                                                                                                    • 1A912 Sending Data to the Display
                                                                                                                                                                    • 1A913 Waterfall Display for Frequency Analysis
                                                                                                                                                                    • 1A914 Waterfall Display for Transient Analysis
                                                                                                                                                                    • 1A915 Waterfall Display for Octave Spectra
                                                                                                                                                                        • 1A10 Swept-Sine Measurements
                                                                                                                                                                          • 1A101 Swept-Sine Overview
                                                                                                                                                                          • 1A102 Choosing Swept-Sine vs FFT Measurements
                                                                                                                                                                          • 1A103 Taking a Swept-Sine Measurement
                                                                                                                                                                          • 1A104 Swept-Sine Measurement Example
                                                                                                                                                                              • Bibliography
                                                                                                                                                                              • Related Titles
                                                                                                                                                                                  • 53191ch2
                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                    • Chapter 2 Signal Conditioning and Modification
                                                                                                                                                                                      • Summary
                                                                                                                                                                                      • 21 Introduction
                                                                                                                                                                                      • 22 Amplifiers
                                                                                                                                                                                        • 221 Operational Amplifier
                                                                                                                                                                                        • 222 Use of Feedback in Opamp
                                                                                                                                                                                        • 223 Voltage Current and Power Amplifiers
                                                                                                                                                                                          • 2231 Charge Amplifiers
                                                                                                                                                                                            • 224 Instrumentation Amplifiers
                                                                                                                                                                                              • 2241 Differential Amplifier
                                                                                                                                                                                              • 2242 Common Mode
                                                                                                                                                                                                • 225 Amplifier Performance Ratings
                                                                                                                                                                                                  • 2251 Common-Mode Rejection Ratio
                                                                                                                                                                                                    • 226 Component Interconnection
                                                                                                                                                                                                      • 2261 Impedance Characteristics
                                                                                                                                                                                                      • 2262 Cascade Connection of Devices
                                                                                                                                                                                                      • 2263 AC-Coupled Ampliers
                                                                                                                                                                                                          • 23 Analog Filters
                                                                                                                                                                                                            • 231 Passive Filters and Active Filters
                                                                                                                                                                                                              • 2311 Number of Poles
                                                                                                                                                                                                                • 232 Low-Pass Filters
                                                                                                                                                                                                                  • 2321 Low-Pass Butterworth Filter
                                                                                                                                                                                                                    • 233 High-Pass Filters
                                                                                                                                                                                                                    • 234 Band-Pass Filters
                                                                                                                                                                                                                      • 2341 Resonance-Type Band-Pass Filters
                                                                                                                                                                                                                        • 235 Band-Reject Filters
                                                                                                                                                                                                                          • 24 Modulators and Demodulators
                                                                                                                                                                                                                            • 241 Amplitude Modulation
                                                                                                                                                                                                                              • 2411 Modulation Theorem
                                                                                                                                                                                                                              • 2412 Side Frequencies and Side Bands
                                                                                                                                                                                                                                • 242 Application of Amplitude Modulation
                                                                                                                                                                                                                                  • 2421 Fault Detection and Diagnosis
                                                                                                                                                                                                                                    • 243 Demodulation
                                                                                                                                                                                                                                      • 25 Analog ndashDigital Conversion
                                                                                                                                                                                                                                        • 251 Digital-to-Analog Conversion
                                                                                                                                                                                                                                          • 2511 DAC Error Sources
                                                                                                                                                                                                                                            • 252 Analog-to-Digital Conversion
                                                                                                                                                                                                                                            • 253 Analog-to-Digital Converter Performance Characteristics
                                                                                                                                                                                                                                              • 2531 Resolution and Quantization Error
                                                                                                                                                                                                                                              • 2532 Monotonicity Nonlinearity and Offset Error
                                                                                                                                                                                                                                              • 2533 Analog-to-Digital Converter Conversion Rate
                                                                                                                                                                                                                                                • 254 Sample-and-Hold Circuitry
                                                                                                                                                                                                                                                • 255 Digital Filters
                                                                                                                                                                                                                                                  • 2551 Software Implementation and Hardware Implementation
                                                                                                                                                                                                                                                      • 26 Bridge Circuits
                                                                                                                                                                                                                                                        • 261 Wheatstone Bridge
                                                                                                                                                                                                                                                        • 262 Constant-Current Bridge
                                                                                                                                                                                                                                                        • 263 Bridge Amplifiers
                                                                                                                                                                                                                                                          • 2631 Half-Bridge Circuits
                                                                                                                                                                                                                                                            • 264 Impedance Bridges
                                                                                                                                                                                                                                                              • 2641 Owen Bridge
                                                                                                                                                                                                                                                              • 2642 Wien-Bridge Oscillator
                                                                                                                                                                                                                                                                  • 27 Linearizing Devices
                                                                                                                                                                                                                                                                    • 271 Linearization by Software
                                                                                                                                                                                                                                                                    • 272 Linearization by Hardware Logic
                                                                                                                                                                                                                                                                    • 273 Analog Linearizing Circuitry
                                                                                                                                                                                                                                                                    • 274 Offsetting Circuitry
                                                                                                                                                                                                                                                                    • 275 Proportional-Output Circuitry
                                                                                                                                                                                                                                                                      • 2751 Curve-Shaping Circuitry
                                                                                                                                                                                                                                                                          • 28 Miscellaneous Signal Modification Circuitry
                                                                                                                                                                                                                                                                            • 281 Phase Shifters
                                                                                                                                                                                                                                                                            • 282 Voltage-to-Frequency Converter
                                                                                                                                                                                                                                                                            • 283 Frequency-to-Voltage Converter
                                                                                                                                                                                                                                                                            • 284 Voltage-to-Current Converters
                                                                                                                                                                                                                                                                            • 285 Peak-Hold Circuits
                                                                                                                                                                                                                                                                              • 29 Signal Analyzers and Display Devices
                                                                                                                                                                                                                                                                                • 291 Signal Analyzers
                                                                                                                                                                                                                                                                                • 292 Oscilloscopes
                                                                                                                                                                                                                                                                                  • 2921 Triggering
                                                                                                                                                                                                                                                                                  • 2922 Lissajous Patterns
                                                                                                                                                                                                                                                                                  • 2923 Digital Oscilloscopes
                                                                                                                                                                                                                                                                                      • Bibliography
                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                          • 53191ch3
                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                            • Chapter 3 Vibration Testing
                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                              • 31 Introduction
                                                                                                                                                                                                                                                                                              • 32 Representation of a Vibration Environment
                                                                                                                                                                                                                                                                                                • 321 Test Signals
                                                                                                                                                                                                                                                                                                  • 3211 Stochastic vs Deterministic Signals
                                                                                                                                                                                                                                                                                                    • 322 Deterministic Signal Representation
                                                                                                                                                                                                                                                                                                      • 3221 Single-Frequency Signals
                                                                                                                                                                                                                                                                                                      • 3222 Sine Sweep
                                                                                                                                                                                                                                                                                                      • 3223 Sine Dwell
                                                                                                                                                                                                                                                                                                      • 3224 Decaying Sine
                                                                                                                                                                                                                                                                                                      • 3225 Sine Beat
                                                                                                                                                                                                                                                                                                      • 3226 Sine Beat with Pauses
                                                                                                                                                                                                                                                                                                      • 3227 Multifrequency Signals
                                                                                                                                                                                                                                                                                                      • 3228 Actual Excitation Records
                                                                                                                                                                                                                                                                                                      • 3229 Simulated Excitation Signals
                                                                                                                                                                                                                                                                                                        • 323 Stochastic Signal Representation
                                                                                                                                                                                                                                                                                                          • 3231 Ergodic Random Signals
                                                                                                                                                                                                                                                                                                          • 3232 Stationary Random Signals
                                                                                                                                                                                                                                                                                                          • 3233 Independent and Uncorrelated Signals
                                                                                                                                                                                                                                                                                                          • 3234 Transmission of Random Excitations
                                                                                                                                                                                                                                                                                                            • 324 Frequency-Domain Representations
                                                                                                                                                                                                                                                                                                              • 3241 Fourier Spectrum Method
                                                                                                                                                                                                                                                                                                              • 3242 Power Spectral Density Method
                                                                                                                                                                                                                                                                                                                • 325 Response Spectrum
                                                                                                                                                                                                                                                                                                                  • 3251 Displacement Velocity and Acceleration Spectra
                                                                                                                                                                                                                                                                                                                  • 3252 Response-Spectra Plotting Paper
                                                                                                                                                                                                                                                                                                                  • 3253 Zero-Period Acceleration
                                                                                                                                                                                                                                                                                                                  • 3254 Uses of Response Spectra
                                                                                                                                                                                                                                                                                                                    • 326 Comparison of Various Representations
                                                                                                                                                                                                                                                                                                                      • 33 Pretest Procedures
                                                                                                                                                                                                                                                                                                                        • 331 Purpose of Testing
                                                                                                                                                                                                                                                                                                                        • 332 Service Functions
                                                                                                                                                                                                                                                                                                                          • 3321 Active Equipment
                                                                                                                                                                                                                                                                                                                          • 3322 Passive Equipment
                                                                                                                                                                                                                                                                                                                          • 3323 Functional Testing
                                                                                                                                                                                                                                                                                                                            • 333 Information Acquisition
                                                                                                                                                                                                                                                                                                                              • 3331 Interface Details
                                                                                                                                                                                                                                                                                                                              • 3332 Effect of Neglecting Interface Dynamics
                                                                                                                                                                                                                                                                                                                              • 3333 Effects of Damping
                                                                                                                                                                                                                                                                                                                              • 3334 Effects of Inertia
                                                                                                                                                                                                                                                                                                                              • 3335 Effect of Natural Frequency
                                                                                                                                                                                                                                                                                                                              • 3336 Effect of Excitation Frequency
                                                                                                                                                                                                                                                                                                                              • 3337 Other Effects of Interface
                                                                                                                                                                                                                                                                                                                                • 334 Test-Program Planning
                                                                                                                                                                                                                                                                                                                                  • 3341 Testing of Cabinet-Mounted Equipment
                                                                                                                                                                                                                                                                                                                                    • 335 Pretest Inspection
                                                                                                                                                                                                                                                                                                                                      • 34 Testing Procedures
                                                                                                                                                                                                                                                                                                                                        • 341 Resonance Search
                                                                                                                                                                                                                                                                                                                                        • 342 Methods of Determining Frequency-Response Functions
                                                                                                                                                                                                                                                                                                                                          • 3421 Fourier Transform Method
                                                                                                                                                                                                                                                                                                                                          • 3422 Spectral Density Method
                                                                                                                                                                                                                                                                                                                                          • 3423 Harmonic Excitation Method
                                                                                                                                                                                                                                                                                                                                            • 343 Resonance-Search Test Methods
                                                                                                                                                                                                                                                                                                                                              • 3431 Hammer (Bump) Test and Drop Test
                                                                                                                                                                                                                                                                                                                                              • 3432 Pluck Test
                                                                                                                                                                                                                                                                                                                                              • 3433 Shaker Tests
                                                                                                                                                                                                                                                                                                                                                • 344 Mechanical Aging
                                                                                                                                                                                                                                                                                                                                                  • 3441 Equivalence for Mechanical Aging
                                                                                                                                                                                                                                                                                                                                                  • 3442 Excitation-Intensity Equivalence
                                                                                                                                                                                                                                                                                                                                                  • 3443 Dynamic-Excitation Equivalence
                                                                                                                                                                                                                                                                                                                                                  • 3444 Cumulative Damage Theory
                                                                                                                                                                                                                                                                                                                                                    • 345 Test-Response Spectrum Generation
                                                                                                                                                                                                                                                                                                                                                    • 346 Instrument Calibration
                                                                                                                                                                                                                                                                                                                                                    • 347 Test-Object Mounting
                                                                                                                                                                                                                                                                                                                                                    • 348 Test-Input Considerations
                                                                                                                                                                                                                                                                                                                                                      • 3481 Test Nomenclature
                                                                                                                                                                                                                                                                                                                                                      • 3482 Testing with Uncorrelated Excitations
                                                                                                                                                                                                                                                                                                                                                      • 3483 Symmetrical Rectilinear Testing
                                                                                                                                                                                                                                                                                                                                                      • 3484 Geometry vs Dynamics
                                                                                                                                                                                                                                                                                                                                                      • 3485 Some Limitations
                                                                                                                                                                                                                                                                                                                                                      • 3486 Testing Black Boxes
                                                                                                                                                                                                                                                                                                                                                      • 3487 Phasing of Excitations
                                                                                                                                                                                                                                                                                                                                                      • 3488 Testing a Gray or White Box
                                                                                                                                                                                                                                                                                                                                                      • 3489 Overtesting in Multitest Sequences
                                                                                                                                                                                                                                                                                                                                                          • 35 Some Practical Information
                                                                                                                                                                                                                                                                                                                                                            • 351 Random Vibration Test Example
                                                                                                                                                                                                                                                                                                                                                            • 352 Vibration Shakers and Control Systems
                                                                                                                                                                                                                                                                                                                                                              • Bibliography
                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                  • 53191ch4
                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                    • Chapter 4 Experimental Modal Analysis
                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                      • 41 Introduction
                                                                                                                                                                                                                                                                                                                                                                      • 42 Frequency-Domain Formulation
                                                                                                                                                                                                                                                                                                                                                                        • 421 Transfer-Function Matrix
                                                                                                                                                                                                                                                                                                                                                                        • 422 Principle of Reciprocity
                                                                                                                                                                                                                                                                                                                                                                          • 43 Experimental Model Development
                                                                                                                                                                                                                                                                                                                                                                            • 431 Extraction of the Time-Domain Model
                                                                                                                                                                                                                                                                                                                                                                              • 44 Curve Fitting of Transfer Functions
                                                                                                                                                                                                                                                                                                                                                                                • 441 Problem Identification
                                                                                                                                                                                                                                                                                                                                                                                • 442 Single- and Multi-Degree-of-Freedom Techniques
                                                                                                                                                                                                                                                                                                                                                                                • 443 Single-Degree-of-Freedom Parameter Extraction in the Frequency Domain
                                                                                                                                                                                                                                                                                                                                                                                  • 4431 Circle-Fit Method
                                                                                                                                                                                                                                                                                                                                                                                    • Case of Viscous Damping
                                                                                                                                                                                                                                                                                                                                                                                    • Case of Hysteretic Damping
                                                                                                                                                                                                                                                                                                                                                                                      • 4432 Peak-Picking Method
                                                                                                                                                                                                                                                                                                                                                                                        • 444 Multi-Degree of Freedom Curve Fitting
                                                                                                                                                                                                                                                                                                                                                                                          • 4441 Formulation of the Method
                                                                                                                                                                                                                                                                                                                                                                                            • 445 A Comment on Static Modes and Rigid-Body Modes
                                                                                                                                                                                                                                                                                                                                                                                            • 446 Residue Extraction
                                                                                                                                                                                                                                                                                                                                                                                              • 45 Laboratory Experiments
                                                                                                                                                                                                                                                                                                                                                                                                • 451 Lumped-Parameter System
                                                                                                                                                                                                                                                                                                                                                                                                  • 4511 Frequency-Domain Test
                                                                                                                                                                                                                                                                                                                                                                                                  • 4512 Time-Domain Tests
                                                                                                                                                                                                                                                                                                                                                                                                    • 452 Distributed-Parameter System
                                                                                                                                                                                                                                                                                                                                                                                                      • 46 Commercial EMA Systems
                                                                                                                                                                                                                                                                                                                                                                                                        • 461 System Configuration
                                                                                                                                                                                                                                                                                                                                                                                                          • 4611 FFT Analysis Options
                                                                                                                                                                                                                                                                                                                                                                                                          • 4612 Modal Analysis Components
                                                                                                                                                                                                                                                                                                                                                                                                              • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                  • 53191ch5
                                                                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                    • Chapter 5 Mechanical Shock
                                                                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                      • 51 Definitions
                                                                                                                                                                                                                                                                                                                                                                                                                        • 511 Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 512 Simple (or Perfect) Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 513 Half-Sine Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 514 Versed-Sine (or Haversine) Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 515 Terminal Peak Sawtooth Shock or Final Peak Sawtooth Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 516 Rectangular Shock
                                                                                                                                                                                                                                                                                                                                                                                                                          • 5161 Trapezoidal Shock
                                                                                                                                                                                                                                                                                                                                                                                                                              • 52 Description in the Time Domain
                                                                                                                                                                                                                                                                                                                                                                                                                              • 53 Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                • 531 Need
                                                                                                                                                                                                                                                                                                                                                                                                                                • 532 Shock Response Spectrum Definition
                                                                                                                                                                                                                                                                                                                                                                                                                                • 533 Response of a Linear One-Degree-of-Freedom System
                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5331 Shock Defined by a Force
                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5332 Shock Defined by an Acceleration
                                                                                                                                                                                                                                                                                                                                                                                                                                    • 534 Definitions
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5341 Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5342 Absolute Acceleration Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5343 Relative Displacement Shock Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5344 Primary Positive Shock Response Spectrum or Initial Positive Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5345 Primary (or Initial) Negative Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5346 Secondary (or Residual) Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5347 Positive (or Maximum Positive) Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5348 Negative (or Maximum Negative) Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5349 Maximax Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53410 Choice of Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                        • 535 Standardized Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5351 Definition
                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5352 Standardized Shock Response Spectra of Simple Shocks
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53521 Half-Sine Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53522 Versed Sine Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53523 Terminal Peak Sawtooth Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53524 Rectangular Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53525 Trapezoidal Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 536 Choice of Damping
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 537 Shock Response Spectra Domains
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 538 Algorithms for Calculation of the Shock Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 539 Choice of the Digitization Frequency of the Signal
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5310 Use of Shock Response Spectra for the Study of Systems with Several Degrees of Freedom
                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 54 Pyroshocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 55 Use of Shock Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 551 Severity Comparison of Several Shocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 552 Test Specification Development from Real Environment Data
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5521 Synthesis of Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5522 Nature of the Specification
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5523 Choice of Shape
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5524 Amplitude
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5525 Duration
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5526 Difficulties
                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 56 Standards
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 561 Types of Standards
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 562 Installation Conditions of Test Item
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 563 Uncertainty Factor
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 564 Bump Test
                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 57 Damage Boundary Curve
                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 571 Definition
                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 572 Analysis of Test Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 58 Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 581 Main Types
                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 582 Impact Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5821 Universal Shock-Test Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 58211 Impact Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 58212 Impulse Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 583 Shock Simulators (Programmers)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5831 Half-Sine Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58311 Shock Duration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58312 Impact Velocity
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58313 Maximum Deformation of the Shock Simulator (Programmer)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58314 Shock Amplitude
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58315 Characteristics of the Target
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5832 Terminal Peak Sawtooth Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5833 Rectangular Pulse ndash Trapezoidal Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5834 Universal Shock Simulator (Programmer)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 58341 Generating a Half-Sine Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 58342 Generating a Terminal Peak Sawtooth Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 58343 Trapezoidal Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 584 Limitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5841 Limitations of the Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5842 Limitations of Shock Simulators
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 585 Pneumatic Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 586 High Impact Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5861 Lightweight High Impact Shock Machine
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5862 Medium Weight High Impact Shock Machine
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 587 Specific Test Facilities
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 59 Generation of Shock Using Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 591 Principle Behind the Generation of a Simple Shape Signal versus Time
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 592 Main Advantages
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 593 Pre- and Postshocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5931 Requirements
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5932 Solutions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 59321 Optimized Pre- and Postpulses
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5933 Incidence on the Shock Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 594 Limitations of Electrodynamic Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5941 Mechanical Limitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 59411 Abacuses
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5942 Electronic Limitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 595 The Use of Electrohydraulic Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 510 Control by a Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 5101 Principle
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 5102 Principal Shapes of Elementary Signals
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 51021 Decaying Sinusoid
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 51022 ZERD Function
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 51023 WAVSIN Waveform
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 5103 Comparison of WAVSIN SHOC Waveforms and Decaying Sinusoid
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 5104 Criticism of Control by a Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 511 Pyrotechnic Shock Simulation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5111 Simulation Using Pyrotechnic Facilities
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5112 Simulation Using Metal-to-Metal Impact
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5113 Simulation Using Electrodynamic Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5114 Simulation Using Conventional Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53191ch6
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Chapter 6 Machine Condition Monitoring and Fault Diagnostics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 61 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 62 Machinery Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 621 Causes of Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 622 Types of Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 623 Frequency of Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 63 Basic Maintenance Strategies
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 631 Run-to-Failure (Breakdown) Maintenance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 632 Scheduled (Preventative) Maintenance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 633 Condition-Based (Predictive Proactive Reliability Centered On-Condition) Maintenance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 64 Factors Which Influence Maintenance Strategy
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 65 Machine Condition Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 651 Periodic Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 652 Continuous Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 66 Transducer Selection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 661 Noncontact Displacement Transducers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 662 Velocity Transducers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 663 Acceleration Transducers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 67 Transducer Location
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 68 Recording and Analysis Instrumentation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 681 Vibration Meters
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 682 Data Collectors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 683 Frequency-Domain Analyzers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 684 Time-Domain Instruments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 685 Tracking Analyzers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 69 Display Formats and Analysis Tools
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 691 Time Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6911 Time-Waveform Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6912 Time-Waveform Indices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6913 Time-Synchronous Averaging
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6914 Negative Averaging
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6915 Orbits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6916 Probability Density Functions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6917 Probability Density Moments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 692 Frequency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6921 Band-Pass Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6922 Shock Pulse (Spike Energy)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6923 Enveloped Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6924 Signature Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6925 Cascades (Waterfall Plots)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6926 Masks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6927 Frequency-Domain Indices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 693 Modal Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 694 Quefrency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 610 Fault Detection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 6101 Standards
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61011 Standards Based on Machinery Type
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61012 Standards Based on Vibration Severity
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 6102 Acceptance Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 61021 Statistical Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 6103 Frequency-Domain Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61031 Limited Band Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61032 Constant Bandwidth Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61033 Constant Percentage Bandwidth Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 611 Fault Diagnostics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 6111 Forcing Functions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61111 Unbalance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61112 Misalignment
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61113 Mechanical Looseness
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61114 Soft Foot
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61115 Rubs
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61116 Resonances
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61117 Oil Whirl
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61118 Oil Whip
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61119 Structural Vibrations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 611110 Foundation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 6112 Specific Machine Components
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 61121 Damaged or Worn Rolling-Element Bearings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 61122 Damaged or Worn Gears
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 6113 Specific Machine Types
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61131 Pumps
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61132 Fans
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61133 Electric Motors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61134 Steam and Gas Turbines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61135 Compressors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61136 Reciprocating Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 6114 Advanced Fault Diagnostic Techniques
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 53191ch7
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • Chapter 7 Vibration-Based Tool Condition Monitoring Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 71 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 72 Mechanics of Turning
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 721 General Terms
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 722 Chatter Vibrations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 723 Tool Wear
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7231 Tool Failure Mechanisms
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7232 Tool Failure Modes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7233 Tool Wear Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7234 Tool Wear Stages
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 73 Vibration Signal Recording
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 731 Direct and Indirect Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 732 Sensor Requirements for Tool Wear Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 733 Force Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7331 Direct Measurement Dynamometers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7332 Indirect Force Sensors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7333 Piezoelectric Strain Sensors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7334 Resistance Strain Gauges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7335 Customized Force Sensors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 734 Acceleration Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 735 Acoustic Emission Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 736 Sensor Comparisons
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 74 Signal Processing for Sensor-Based Tool Condition Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 741 Feature Extraction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7411 Time Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7412 Frequency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7413 Statistical Processing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7414 TimendashFrequency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 742 Feature Selection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 75 Wear ModelDecision-Making for Sensor-Based Tool Condition Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 751 Trending Threshold
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 752 Neural Networks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7521 Unsupervised Networks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7522 Supervised Networks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 753 Fuzzy Logic
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 754 Other Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 76 Conclusion
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53191ch8
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Chapter 8 Fault Diagnosis of Helicopter Gearboxes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 81 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 82 Abnormality Scaling
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 83 The Structure-Based Connectionist Network
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 84 Sensor Location Selection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 841 Coverage Index
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 842 Overlap Index
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 843 Monitoring Effectiveness
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 85 A Case Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 851 Structural and Featural Influences
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 852 Evaluation of Influences
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 853 Fault Detection Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 854 Fault Diagnostic Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 8541 Faulty Subsystem Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 8542 Faulty Component Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 855 Sensor Location Evaluation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 856 Sensor Location Validation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 86 Conclusion
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 53191ch9
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Chapter 9 Vibration Suppression and Monitoring in Precision Motion Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 91 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 92 Mechanical Design to Minimize Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 921 Stability and Static Determinacy of Machine Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 922 Two-Dimensional Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 923 Three-Dimensional Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 93 Adaptive Notch Filter
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 931 Fast Fourier Transform
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 932 Simulation and Experiments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 94 Real-Time Vibration Analyzer
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 941 Learning Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 942 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 943 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 944 Experiments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 9441 Input Variables mdash the Evaluation Criteria
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 94411 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 94412 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 9442 Evaluation Rules
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 94421 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 94422 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 9443 Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 94431 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 94432 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 95 Practical Insights and Case Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 96 Conclusions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 53191ch10
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Chapter 10 Vibration and Shock Problems of Civil Engineering Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 101 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 102 Earthquake-Induced Vibration of Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1021 Seismicity and Ground Motions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1022 Influence of Local Site Conditions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1023 Response of Structures to Ground Motions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1024 Dynamic Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10241 Equations of Motion for Linear Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10242 Equations of Motion for Linear Multiple-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1025 Earthquake Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10251 Elastic Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10252 Smoothed Design Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10253 Ductility-Modified Response Spectrum Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1026 Design Philosophy and the Code Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10261 Performance-Based Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1027 Analysis Options for Earthquake Effects
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10271 Dynamic Time History Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10272 Response Spectrum Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 102721 Response Spectrum Analysis of Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 102722 Response Spectrum Analysis of Multi-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10273 Equivalent Static Analysis (Force-Based Approach)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10274 Displacement-Based Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1028 SoilndashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1029 Active and Passive Control Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 10210 Worked Examples
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 103 Dynamic Effects of Wind Loading on Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1031 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1032 Wind Speed
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1033 Design Structures for Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10331 Types of Wind Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10332 Design Criteria
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10333 Static Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1034 Along and Across-Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10341 Along-Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10342 Across-Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1035 Wind Tunnel Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1036 Comfort Criteria Human Response to Building Motion
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1037 Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1038 Comparison with Earthquake Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 104 Vibrations Due to Fluid ndashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1041 Added Mass and Inertial Coupling
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1042 Wave-Induced Vibration of Structure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 105 Blast Loading and Blast Effects on Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1051 Explosions and Blast Phenomenon
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1052 Explosive Air-Blast Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10521 Blast Wave Scaling Laws
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10522 Prediction of Blast Pressure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1053 Gas Explosion Loading and Effect of Internal Explosions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1054 Structural Response to Blast Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10541 Elastic Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10542 Elasto-Plastic Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1055 Material Behaviors at High Strain Rate
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10551 Dynamic Properties of Concrete under High Strain Rates
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10552 Dynamic Properties of Reinforcing Steel under High Strain Rates
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1056 Failure Modes of Blast-Loaded Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10561 Global Structural Behavior
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10562 Localized Structural Behavior
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10563 PressurendashImpulse ( PndashI ) Diagrams
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1057 Blast WavendashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1058 Effect of Ground Shocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10581 Loads from Air-Induced Ground Shock
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10582 Loads from Direct Ground Shock
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1059 Technical Design Manuals for Blast-Resistant Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 10510 Computer Programs for Blast and Shock Effects
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 106 Impact Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1061 Structural Impact between Two Bodies mdash Hard Impact and Soft Impact
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1062 Example mdash Aircraft Impact
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 107 Floor Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1071 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1072 Types of Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10721 Walking
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10722 Rhythmic Activities
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10723 Mechanical Equipment
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10724 Analysis Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1073 Natural Frequency of Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10731 Computing the Natural Frequency
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10732 Computing Deflection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10733 Damping
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10734 Resonance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1074 Vibration Caused by Walking
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10741 Minimum Natural Frequency
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1075 Design for Rhythmic Excitation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10751 Harmonics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10752 Minimum Natural Frequency
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1076 Example mdash Vibration Analysis of a Reinforced Concrete Floor
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Related Titles
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                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Chapter 11 Seismic Base Isolation and Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 111 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1111 From Ductility Design to Base Isolation and Control Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1112 The Importance of Reducing Seismic Input and Response
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 112 Seismic Base Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1121 Historical Development of Base Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1122 Basic Principle
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1123 Issues in Seismic Base Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11231 Performance Criteria
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11232 Type of Structure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11233 Site Characteristics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11234 Retrofit Issues
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11235 Design of Building Services
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11236 Expected Life of Isolator
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1124 Seismic Isolation Devices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11241 Laminated Rubber Bearings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11242 Lead Rubber Bearing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11243 Friction-Based Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11244 Other Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1125 Design of Isolation Devices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11251 High-Damping Rubber Bearing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112511 Stability against Buckling
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112512 Stability against Roll Out
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11252 Lead Rubber Bearings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112521 Design of Lead Plug
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112522 Design of Laminated Rubber Bearing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11253 Design of Friction Pendulum System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1126 Verification of Properties of Isolation Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11261 Tests for Isolation Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 112611 System Characterization Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 112612 Prototype Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 112613 Quality Control Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11262 Uniform Building Code Recommendations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112621 Units Dependent on Loading Rates
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112622 Units Dependent on Bilateral Load
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112623 System Adequacy
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1127 Analysis of Base-Isolated Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11271 Modeling of a Superstructure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11272 Modeling of Isolation System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11273 Static Analysis Procedure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11274 Dynamic Analysis Procedure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 112741 Response Spectrum Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 112742 Time-History Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11275 Software for Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1128 Experimental Methods for Isolated Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1129 Implementation of Seismic Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11291 New Construction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112911 Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112912 Bridges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11292 Seismic Retrofit
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112921 Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112922 Bridges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11293 Other Implementations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 11210 Performance during Past Earthquakes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 112101 Performance of Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 112102 Performance of Bridges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 113 Seismic Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1131 Historical Development of Seismic Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1132 Basic Principles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11321 Passive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11322 Active Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11323 Semiactive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11324 Hybrid Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11325 Categorization of Basic Principles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1133 Important Issues in Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11331 SoilndashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11332 DevicendashStructure Interaction and Time Delay
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11333 Design Guidelines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1134 Vibration-Control Devices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11341 Passive Control Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113411 Metallic Yielding Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113412 Friction Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113413 Viscoelastic Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113414 Viscous Fluid Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113415 Tuned Mass Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11342 Active Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113421 Electromagnetic Actuator
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113422 Hydraulic Actuators
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11343 Semiactive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113431 Variable-Orifice Hydraulic Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113432 Controllable Fluid Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113433 Controllable Friction Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11344 Hybrid Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1135 Control Algorithm
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11351 Active Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11352 Semiactive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113521 Common Control Schemes for Controllable Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113522 Special Control Schemes for Controllable Damper
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1136 Experimental Performance Verification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11361 Shaking Table Tests of a Flexible Structural Model with TMD AMD and ATMD
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11362 Substructure Hybrid Test
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113621 Hybrid Tests Using Hydraulic Actuator
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113622 Hybrid Tests Using Shaking Table
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113623 Hybrid Tests Using Inertia-Force-Driven Loading System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1137 Implementations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11371 Semiactive Control of Full-Scale Structures Using Variable Joint Damper System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113711 Background of Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113712 Test System Set Up
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113713 Control Algorithm
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113714 Test Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11372 Application of Structural Control Technologies to Seismic Retrofit of a Cable-Stayed Bridge
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113721 Background of Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113722 Basic Concept of Seismic Retrofit
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113723 Modal Shape Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113724 Time-History Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113725 Soil ndash Structure Interaction Effect
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113726 Semiactive Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Bibliography
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                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Chapter 12 Seismic Random Vibration of Long-Span Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 121 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1211 Basic Concepts of Random Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12111 Stationary Random Process
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12112 Nonstationary Random Process
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1212 Three Methods for Structural Seismic Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12121 Response Spectrum Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12122 Time-History Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12123 Random Vibration Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 121231 Davenport Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 121232 Vanmarcke Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 12124 Comparisons of the Three Seismic-Analysis Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 122 Seismic Random-Excitation Fields
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1221 Power Spectral Density of Spatially Varying Ground Acceleration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1222 Several Coherence Models
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12221 FengndashHu Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12222 Harichandran ndashVanmarcke Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12223 LohndashYeh Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12224 OliveirandashHaondashPenzien Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12225 LucondashWong Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12226 QundashWangndashWang Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1223 Generation of Ground Acceleration Power Spectral Density Curves from Acceleration Response Spectrum Curves
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12231 Kaul Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12232 Iteration Scheme
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1224 Seismic Equations of Motion of Long-Span Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1225 Seismic Waves and Their Geometrical Expressions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 123 Pseudoexcitation Method for Structural Random Vibration Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1231 Structures Subjected to Stationary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12311 Single Stationary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12312 Multiple Stationary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1232 Structures Subjected to Nonstationary Random Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12321 Structures Subjected to Uniformly Modulated Evolutionary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 123211 Single Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 123212 Multiple Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12322 Structures Subjected to Nonuniformly Modulated Evolutionary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 123221 Single Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 123222 Multiple Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1233 Precise Integration Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12331 Precise Integration of Exponential Matrices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12332 Particular Solutions and Precise Integration Formulas for Various Forms of Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 123321 Linear Loading Form (HPD-L Form)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 123322 Sinusoidal Loading Form (HPD-S Form)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 123323 Exponentially Decaying Sinusoidal Loading Form (HPD-E Form)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 124 Long-Span Structures Subjected to Stationary Random Ground Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1241 The Solution of Equations of Motion Using the Pseudoexcitation Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1242 Numerical Comparisons with Other Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12421 Song-Hua-Jiang Suspension Bridge
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 124211 All Supports Move Uniformly
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 124212 Wave Passage Effect Is Taken into Account
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 124213 Wave-Passage Effect and Incoherence Effect Are Jointly Taken into Account
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 12422 San Joaquin Concrete Bridge
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 125 Long-Span Structures Subjected to Nonstationary Random Ground Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1251 Modulation Functions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1252 The Formulas for Nonstationary Multiexcitation Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1253 Expected Extreme Values of Nonstationary Random Processes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1254 Numerical Comparisons with the Corresponding Stationary Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 126 Conclusions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 53191ch13
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Chapter 13 Seismic Qualification of Equipment
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 131 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 132 Distribution Qualification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1321 Drive-Signal Generation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1322 Distribution Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1323 Test Procedures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 133 Seismic Qualification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1331 Stages of Seismic Qualification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1332 Test Preliminaries
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1333 Single-Frequency Testing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1334 Multifrequency Testing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1335 Generation of RRS Specifications
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 53191ch14
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Chapter 14 Human Response to Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 141 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 142 Vibration Excitations on Humans
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1421 Excitation Characteristics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 143 Human Response to Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1431 Vibration Perception
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1432 Frequency Weighting Curve
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1433 Iso-Perception Curves
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1434 Detection Threshold Curve
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 144 Regulation of Human Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1441 Acceptable Vibration Levels in Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1442 Whole-Body Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1443 HandndashArm Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
Page 23: Vibration Monitoring, Testing, and Instrumentationpreview.kingborn.net › 646000 › d1a74678d91943e5ba1d5e... · The MEMS Handbook, Second Edition MEMS: Introduction and Fundamentals

Reaction-type shakers driven by inertia are widely used for the prototype testing of civil engineering

structures Their first application dates back to 1935 Inertial shakers are capable of producing

intermediate excitation forces The force generated is limited by the strength of the carriage frame The

frequency range of operation and the maximum velocity and acceleration capabilities are also

intermediate for inertial shakers whereas the maximum displacement capability is typically low A major

limitation of inertial shakers is that their excitation force is exclusively sinusoidal and that the force

amplitude is directly proportional to the square of the excitation frequency As a result complex and

random excitation testing constant-force testing (for example transmissibility tests and constant-force

sine-sweep tests) and flexibility to vary the force amplitude or the displacement amplitude during a test

are not generally feasible with this type of shakers Excitation frequency and amplitude can be varied

during testing however by incorporating a variable-speed drive for the motor The sinusoidal excitation

generated by inertial shakers is virtually undistorted which gives them an advantage over the other types

of shakers when used in sine-dwell and sine-sweep tests Small portable shakers with low-force capability

are available for use in on-site testing

1216 Electromagnetic Shakers

In electromagnetic shakers or ldquoelectrodynamic excitersrdquo the motion is generated using the principle of

operation of an electric motor Specifically the excitation force is produced when a variable excitation

signal (electrical) is passed through a moving coil placed in a magnetic field

The components of a commercial electromagnetic shaker are shown in Figure 18 A steady magnetic

field is generated by a stationary electromagnet that consists of field coils wound on a ferromagnetic base

that is rigidly attached to a protective shell structure The shaker head has a coil wound around it When

the excitation electrical signal is passed through this drive coil the shaker head which is supported on

flexure mounts will be set in motion The shaker head consists of the test table on which the test object

is mounted Shakers with interchangeable heads are available The choice of appropriate shaker head is

based on the geometry and mounting features of the test object The shaker head can be turned to

different angles by means of a swivel joint In this manner different directions of excitation (in biaxial

and triaxial testing) can be obtained

FIGURE 17 Sketch of a counter-rotating-mass inertial shaker

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copy 2007 by Taylor amp Francis Group LLC

122 Dynamics of Electromagnetic Shakers

Consider a single axis electromagnetic shaker (Figure 18) with a test object having a single natural

frequency of importance within the test frequency range The dynamic interactions between the shaker

and the test object give rise to two significant natural frequencies (and correspondingly two significant

resonances) These appear as peaks in the frequency response curve of the test setup Furthermore the

natural frequency (resonance) of the test package alone causes a ldquotroughrdquo or depression (antiresonance)

in the frequency response curve of the overall test setup To explain this characteristic consider the

dynamic model shown in Figure 19 The following mechanical parameters are defined for

Figure 19(a) m k and b are the mass stiffness and equivalent viscous damping constant respectively

of the test package and me ke and be are the corresponding parameters of the exciter (shaker) Also in

the equivalent electrical circuit of the shaker head as shown in Figure 19(b) the following electrical

parameters are defined Re and Le are the resistance and (leakage) inductance and kb is the back

electromotive force (back emf) of the linear motor Assuming that the gravitational forces are supported

FIGURE 18 Schematic sectional view of a typical electromagnetic shaker manufactured by Bruel and Kjaer

Denmark

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copy 2007 by Taylor amp Francis Group LLC

by the static deflections of the flexible elements and that the displacements are measured from the static

equilibrium position we have the following system equations

Test object meuroy frac14 2kethy2 yeTHORN2 beth_y2 _yeTHORN eth119THORNShaker head me euroye frac14 fe thorn kethy2 yeTHORN thorn beth_y2 _yeTHORN2 key 2 be _ye eth120THORN

Electrical Lediedt

thorn Reie thorn kb _ye frac14 vethtTHORN eth121THORN

The electromagnetic force fe generated in the shaker head is a result of the interaction of the magnetic

field generated by the current ie with coil of the moving shaker head and the constant magnetic field

(stator) in which the head coil is located Here we have

fe frac14 kbie eth122THORNNote that v(t) is the voltage signal that is applied by the amplifier to the shaker coil ye is the displacement

of the shaker head and y is the displacement response of the test package

It is assumed that kb has consistent electrical and mechanical units (Vmsec and NA) Usually

the electrical time constant of the shaker is quite small compared with the primarily mechanical

time constants of the shaker and the test package In such cases the Ledie=dt term in Equation 121 may

be neglected Consequently the equations from Equation 119 through Equation 122 may be

expressed in the Laplace (frequency) domain with the Laplace variable s taking the place of the derivative

d=dt as

ethms2 thorn bsthorn kTHORNy frac14 ethbsthorn kTHORNye eth123THORN

FIGURE 19 Dynamic models of an electromagnetic shaker and a flexible test package (a) mechanical model

(b) electrical model

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copy 2007 by Taylor amp Francis Group LLC

frac12mes2 thorn ethbthorn beTHORNsthorn ethkthorn keTHORN ye frac14 ethbsthorn kTHORNy thorn kb

Rev2

k2bs

Reye eth124THORN

It follows that the transfer function of the shaker head motion with respect to the excitation voltage is

given by

yevfrac14 kb

Re

DethsTHORNDdethsTHORN eth125THORN

where DethsTHORN is the characteristic function of the primary dynamics of the test object

DethsTHORN frac14 ms2 thorn bsthorn k eth126THORN

and DdethsTHORN is the characteristic function of the primary dynamic interactions between the shaker and thetest object

DcethsTHORN frac14 mmes4 thorn frac12methbe thorn bthorn boTHORN thornmeb s

3 thorn frac12methke thorn kTHORN thornmekthorn bethbe thorn boTHORN s2thorn frac12bke thorn ethbe thorn boTHORNk sthorn kke

eth127THORN

where

bo frac14 k2bRe

eth128THORN

It is clear that under low damping conditions DdethsTHORN will produce two resonances as it is fourth order in sand similarly DethsTHORN will produce one antiresonance (trough) corresponding to the resonance of the testobject Note that in the frequency domain s frac14 jv and hence the frequency response function given by

Equation 125 is in fact

yevfrac14 kb

Rb

DethjvTHORNDdethjvTHORN eth129THORN

The magnitude of this frequency response function for a typical test system is sketched in Figure 110

Note that this curve is for the ldquoopen-looprdquo case where there is no feedback from the shaker controller

In practice the shaker controller will be able

to compensate for the resonances and anti-

resonances to some degree depending on its

effectiveness

The main advantages of electromagnetic

shakers are their high frequency range of

operation their high degree of operating flexi-

bility and the high level of accuracy of the

generated shaker motion Faithful reproduction

of complex excitations is possible because of the

advanced electronics and control systems used in

this type of shakers Electromagnetic shakers are

not suitable for heavy-duty applications (large test

objects) however High test-input accelerations

are possible at high frequencies when electromag-

netic shakers are used but their displacement and

velocity capabilities are limited to low or

intermediate values (see Table 11)

100

10

1 10 100Excitation Frequency (Hz)

Antiresonance

Resonance

Shak

erD

ispl

acem

entM

agni

tude

Resonance

1000

FIGURE 110 Frequency response curve of a typical

electromagnetic shaker with a test object

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copy 2007 by Taylor amp Francis Group LLC

1221 Transient Exciters

Other varieties of exciters are commonly used in

transient-type vibration testing In these tests

either an impulsive force or an initial excitation is

applied to the test object and the resulting

response is monitored The excitations and the

responses are ldquotransientrdquo in this case Hammer

test drop tests and pluck tests fall into this

category For example a hammer test may be

conducted by hitting the object with an instru-

mented hammer and then measuring the response

of the object The hammer has a force sensor at its

tip as sketched in Figure 111 A piezoelectric or

strain-gage type force sensor may be used More

sophisticated hammers have impedance heads in

place of force sensors An impedance head

measures force and acceleration simultaneously

The results of a hammer test will depend on many

factors for example the dynamics of the hammer

body how firmly the hammer is held during the

impact how quickly the impact is applied and

whether there are multiple impacts

13 Control System

The two primary functions of the shaker control system in vibration testing are (1) to guarantee that the

specified excitation is applied to the test object and (2) to ensure that the dynamic stability (motion

constraints) of the test setup is preserved An operational block diagram illustrating these control

functions is given in Figure 112 The reference input to the control system represents the desired

excitation force that should be applied to the test object In the absence of any control however the force

reaching the test object will be distorted primarily because of (1) dynamic interactions and

nonlinearities of the shaker the test table the mounting fixtures the auxiliary instruments and the test

object itself (2) noise and errors in the signal generator amplifiers filters and other equipment and (3)

external loads and disturbances acting on the test object and other components (for example external

restraints aerodynamic forces friction) To compensate for these distorting factors response

measurements (displacements velocities acceleration and so on) are made at various locations in the

test setup and are used to control the system dynamics In particular the responses of the shaker the test

table and the test object are measured These responses are used to compare the actual excitation felt by

FIGURE 111 An instrumented hammer used in bump

tests or hammer tests

ExcitationInput

(Reference)

Feedback Paths

DriveSignal

ShakerResponse

TestTable

TestObject

Test ObjectResponse

Test TableResponseExciter

(Shaker)(Ram)

Controllerand

Amplifier

FIGURE 112 Operational block diagram illustrating a general shaker control system

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copy 2007 by Taylor amp Francis Group LLC

the test object at the shaker interface with the desired (specified) input The drive signal to the shaker is

modified depending on the error that is present

Two types of control are commonly employed in shaker apparatus simple manual control and

complex automatic control Manual control normally consists of simple open-loop trial-and-error

methods of manual adjustments (or calibration) of the control equipment to obtain a desired dynamic

response The actual response is usually monitored (on an oscilloscope or frequency analyzer screen for

example) during manual-control operations The pretest adjustments in manual control can be very

time-consuming as a result the test object might be subjected to overtesting which could produce

cumulative damage is undesirable and could defeat the test purpose Furthermore the calibration

procedure for the experimental setup must be repeated for each new test object

The disadvantages ofmanual control suggest that automatic control is desirable in complex test schemes

in which high accuracy of testing is desired The first step of automatic control involves automatic

measurement of the system response using control sensors and transducers The measurement is then fed

back into the control system which instantaneously determines the best drive signal to actuate the shaker

in order to get the desired excitation This may be done by either analog or digital methods

Primitive control systems require an accurate mathematical description of the test object This

dependency of the control system on the knowledge of test-object dynamics is clearly undesirable

Performance of a good control system should not be considerably affected by the dynamic interactions

and nonlinearities of the test object or by the nature of the excitation Proper selection of feedback signals

and control-system components can reduce such effects and will make the system robust

In the response-spectrum method of vibration testing it is customary to use displacement control at

low frequencies velocity control at intermediate frequency and acceleration control at high frequencies

This necessitates feedback of displacement velocity and acceleration responses Generally however the

most important feedback is the velocity feedback In sine-sweep tests the shaker velocity must change

steadily over the frequency band of interest In particular the velocity control must be precise near the

resonances of the test object Velocity (speed) feedback has a stabilizing effect on the dynamics which is

desirable This effect is particularly useful in ensuring stability in motion when testing is done near

resonances of lightly damped test objects On the contrary displacement (position) feedback can have a

destabilizing effect on some systems particularly when high feedback gains are used

The controller usually consists of various instruments equipment and computation hardware and

software Often the functions of the data-acquisition and processing system overlap with those of the

controller to some extent As an example consider the digital-controller of vibration testing apparatus

First the responses are measured through sensors (and transducers) filtered and amplified

(conditioned) These data channels may be passed through a multiplexer whose purpose is to select

one data channel at a time for processing Most modern data acquisition hardware does not need a

separate multiplexer to handle multiple signals The analog data are converted into digital data using

analog-to-digital converters (ADCs) The resulting sampled data are stored on a disk or as a block data in

the computer memory The reference input signal (typically a signal recorded on an FM tape) is also

sampled (if it is not already in the digital form) using an ADC and fed into the computer Digital

processing is done on the reference signal and the response data with the objective of computing the

command signal to drive the shaker The digital command signal is converted into an analog signal using

a digital-to-analog converter (DAC) and amplified (conditioned) before it is used to drive the exciter

The nature of the control components depends to a large extent on the nature and objectives of the

particular test to be conducted Some of the basic components in a shaker controller are described in

the following subsections

131 Components of a Shaker Controller

1311 Compressor

A compressor circuit is incorporated in automatic excitation control devices to control the excitation-

input level automatically The level of control depends on the feedback signal from a control sensor and

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copy 2007 by Taylor amp Francis Group LLC

the specified (reference) excitation signal Usually the compressor circuit is included in the excitation-

signal generator (for example in a sine generator) The control by this means may be done on the basis of

a single-frequency component (eg the fundamental frequency)

1312 Equalizer (Spectrum Shaper)

Random-signal equalizers are used to shape the spectrum of a random signal in a desired manner In

essence and equalizer consists of a bank of narrow-band filters (for example 80 filters) in parallel over

the operating frequency range By passing the signal through each filter the spectral density (or the mean

square value) of the signal in that narrow frequency band (for example each one-third-octave band) is

determined This is compared with the desired spectral level and automatic adjustment is made in that

filter in case there is an error In some systems response-spectrum analysis is made in place of power

spectral density analysis In that case the equalizer consists of a bank of simple oscillators whose

resonant frequencies are distributed over the operating frequency range of the equalizer The feedback

signal is passed through each oscillator and the peak value of its output is determined This value is

compared with the desired response spectrum value at that frequency If there is an error automatic gain

adjustment is made in the appropriate excitation signal components

Random-noise equalizers are used in conjunction with random signal generators They receive

feedback signals from the control sensors In some digital control systems there are algorithms (software)

that are used to iteratively converge the spectrum of the excitation signal felt by the test object into the

desired spectrum

1313 Tracking Filter

Many vibration tests are based on single-frequency excitations In such cases the control functions

should be performed on the basis of the amplitudes of the fundamental-frequency component of the

signal A tracking filter is simply a frequency-tuned band-pass filter It automatically tunes the center

frequency of its very narrow-band-pass filter to the frequency of a carrier signal Then when a noisy

signal is passed through the tuned filter the output of the filter will be the required fundamental

frequency component in the signal Tracking filters also are useful in obtaining amplitudendashfrequency

plots using an XndashY plotter In such cases the frequency value comes from the signal generator (sweep

oscillator) which produces the carrier signal to the tracking filter The tracking filter then determines the

corresponding amplitude of a signal that is fed into it Most tracking filters have dual channels so that two

signals can be handled (tracked) simultaneously

1314 Excitation Controller (Amplitude Servo-Monitor)

An excitation controller is typically an integral part of the signal generator It can be set so that automatic

sweep between two frequency limits can be performed at a selected sweep rate (linear or logarithmic)

More advanced excitation controllers have the capability of an automatic switch-over between constant-

displacement constant-velocity and constant-acceleration excitation-input control at specified

frequencies over the sweep frequency interval Consequently integrator circuits should be present

within the excitation controller unit to determine velocities and displacements from acceleration signals

Sometimes integration is performed by a separate unit called a vibration meter This unit also offers

the operator the capability of selecting the desired level of each signal (acceleration velocity or

displacement) There is an automatic cut-off level for large displacement values that could result from

noise in acceleration signals A compressor is also a subcomponent of the excitation controller The

complete unit is sometimes known as an amplitude servo-monitor

132 Signal-Generating Equipment

Shakers are force-generating devices that are operated using drive (excitation) signals generated from a

source The excitation-signal source is known as the signal generator Three major types of signal

generators are used in vibration testing applications (1) oscillators (2) random-signal generators and

(3) storage devices In some units oscillators and random-signal generators are combined We shall

Vibration Instrumentation 1-17

53191mdash522007mdash1202mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

discuss these two generators separately however because of their difference in function It also should be

noted that almost any digital signal (deterministic or random) can be generated by a digital computer

using a suitable computer program the signal eventually can be passed through a DAC to obtain

the corresponding analog signal These lsquodigitalrsquo signal generators along with analog sources such as

magnetic tape players (FM) are classified into the category of storage devices

The dynamic range of equipment is the ratio of the maximum and minimum output levels (expressed

in decibels) at which it is capable of operating without significant error This is an important specification

for many types of equipment particularly for signal-generating devices The output level of the signal

generator should be set to a value within its dynamic range

1321 Oscillators

Oscillators are essentially single-frequency generators Typically sine signals are generated but other

waveforms (such as rectangular and triangular pulses) are also available in most oscillators Normally

an oscillator has two modes of operation (1) sweeping up and down between two frequency limits and

(2) dwelling at a specified frequency In the sweep operation the sweep rate should be specified This can

be done either on a linear scale (Hzmin) or on a logarithmic scale (octavesmin) In the dwell operation

the frequency points (or intervals) should be specified In either case a desired signal level can be chosen

using the gain-control knob An oscillator that is operated exclusively in the sweep mode is called a sweep

oscillator

The early generation of oscillators employed variable inductor-capacitor types of electronic circuits to

generate signals oscillating at a desired frequency The oscillator is tuned to the required frequency by

varying the capacitance or inductance parameters A DC voltage is applied to energize the capacitor

and to obtain the desired oscillating voltage signal which subsequently is amplified and conditioned

Modern oscillators use operational amplifier circuits along with resistor capacitor and semiconductor

(SC) elements Also common are crystal (quartz) parallel-resonance oscillators used to generate voltage

signals accurately at a fixed frequency The circuit is activated using a DC-voltage source Other

frequencies of interest are obtained by passing this high-frequency signal through a frequency converter

The signal is then conditioned (amplified and filtered) Required shaping (for example rectangular

pulse) is obtained using a shape circuit Finally the required signal level is obtained by passing the

resulting signal through a variable-gain amplifier A block diagram of an oscillator illustrating various

stages in the generation of a periodic signal is given in Figure 113

A typical oscillator offers a choice of several (typically six) linear and logarithmic frequency ranges and

a sizable level of control capability (for example 80 dB) Upper and lower frequency limits in a sweep can

be preset on the front panel to any of the available frequency ranges Sweep-rate settings are continuously

DC Voltage

Oscillator

FrequencySpecification

FrequencyConverter

FilterAmplifier

ShaperPeriodicSignal

FrequencyCounter

Fixed-FrequencySignal

Variable-GainOutput

Amplifier

SignalSpecification

LevelSpecification

FIGURE 113 Block diagram of an oscillator-type signal generator

Vibration Monitoring Testing and Instrumentation1-18

53191mdash522007mdash1202mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

  • 53191fm
    • Vibration Monitoring Testing and Instrumentation
      • Preface
      • Acknowledgments
      • Editor-in-Chief
      • Contributors
      • Contents
      • Related Titles
          • 53191ch1
            • Table of Contents
            • Chapter 1 Vibration Instrumentation
              • Summary
              • 11 Introduction
              • 12 Vibration Exciters
                • 121 Shaker Selection
                  • 1211 Force Rating
                  • 1212 Power Rating
                  • 1213 Stroke Rating
                  • 1214 Hydraulic Shakers
                  • 1215 Inertial Shakers
                  • 1216 Electromagnetic Shakers
                    • 122 Dynamics of Electromagnetic Shakers
                      • 1221 Transient Exciters
                          • 13 Control System
                            • 131 Components of a Shaker Controller
                              • 1311 Compressor
                              • 1312 Equalizer (Spectrum Shaper)
                              • 1313 Tracking Filter
                              • 1314 Excitation Controller (Amplitude Servo-Monitor)
                                • 132 Signal-Generating Equipment
                                  • 1321 Oscillators
                                  • 1322 Random Signal Generators
                                  • 1323 Tape Players
                                  • 1324 Data Processing
                                      • 14 Performance Specification
                                        • 141 Parameters for Performance Specification
                                          • 1411 Time-Domain Specifications
                                          • 1412 Frequency-Domain Specifications
                                            • 142 Linearity
                                            • 143 Instrument Ratings
                                              • 1431 Rating Parameters
                                                • 144 Accuracy and Precision
                                                  • 15 Motion Sensors and Transducers
                                                    • 151 Potentiometer
                                                      • 1511 Potentiometer Resolution
                                                      • 1512 Optical Potentiometer
                                                        • 152 Variable-Inductance Transducers
                                                          • 1521 Mutual-Induction Transducers
                                                          • 1522 Linear-Variable Differential Transformer
                                                          • 1523 Signal Conditioning
                                                            • 153 Mutual-Induction Proximity Sensor
                                                            • 154 Selfinduction Transducers
                                                            • 155 Permanent-Magnet Transducers
                                                            • 156 Alternating Current Permanent-Magnet Tachometer
                                                            • 157 Alternating Current Induction Tachometer
                                                            • 158 Eddy Current Transducers
                                                            • 159 Variable-Capacitance Transducers
                                                              • 1591 Capacitive Displacement Sensors
                                                              • 1592 Capacitive Angular Velocity Sensor
                                                              • 1593 Capacitance Bridge Circuit
                                                                • 1510 Piezoelectric Transducers
                                                                  • 15101 Sensitivity
                                                                  • 15102 Piezoelectric Accelerometer
                                                                  • 15103 Charge Amplifier
                                                                      • 16 Torque Force and Other Sensors
                                                                        • 161 Strain Gage Sensors
                                                                          • 1611 Equations for Strain Gage Measurements
                                                                          • 1612 Bridge Sensitivity
                                                                          • 1613 The Bridge Constant
                                                                          • 1614 The Calibration Constant
                                                                          • 1615 Data Acquisition
                                                                          • 1616 Accuracy Considerations
                                                                          • 1617 Semiconductor Strain Gages
                                                                          • 1618 Force and Torque Sensors
                                                                          • 1619 Strain Gage Torque Sensors
                                                                          • 16110 Deflection Torque Sensors
                                                                          • 16111 Variable-Reluctance Torque Sensor
                                                                          • 16112 Reaction Torque Sensors
                                                                            • 162 Miscellaneous Sensors
                                                                              • 1621 Stroboscope
                                                                              • 1622 Fiber Optic Sensors and Lasers
                                                                              • 1623 Fiber-Optic Gyroscope
                                                                              • 1624 Laser Doppler Interferometer
                                                                              • 1625 Ultrasonic Sensors
                                                                              • 1626 Gyroscopic Sensors
                                                                                  • References
                                                                                  • Appendix 1A Virtual Instrumentation for Data Acquisition Analysis and Presentation
                                                                                    • Summary
                                                                                    • List of Abbreviations
                                                                                    • 1A1 Dynamic Signals
                                                                                      • 1A11 Acquiring and Simulating Dynamic Signals
                                                                                        • 1A111 Aliasing
                                                                                        • 1A112 Time Continuity
                                                                                            • 1A2 Measurement Configuration Considerations
                                                                                              • 1A21 Input Signal Considerations
                                                                                                • 1A211 Input Pseudodifferential and Differential Configuration
                                                                                                • 1A212 Gain
                                                                                                • 1A213 Input Coupling
                                                                                                • 1A214 Integrated Electronic Piezoelectric Excitation
                                                                                                • 1A215 Nyquist Frequency and Bandwidth
                                                                                                • 1A216 Analog-to-Digital Conversion
                                                                                                • 1A217 Antialias Filters
                                                                                                • 1A218 Input Filter Delay
                                                                                                • 1A219 Overload Detection
                                                                                                  • 1A22 Output Signal Considerations
                                                                                                    • 1A221 Output Pseudodifferential and Differential Configuration
                                                                                                    • 1A222 Attenuation
                                                                                                    • 1A223 Digital-to-Analog Conversion
                                                                                                    • 1A224 Anti-imaging and Interpolation Filters
                                                                                                    • 1A225 Output Filter Delay
                                                                                                        • 1A3 Scaling and Calibration
                                                                                                          • 1A31 Scaling to Engineering Units
                                                                                                          • 1A32 Performing System Calibration
                                                                                                            • 1A321 Propagation Delay Calibration
                                                                                                                • 1A4 Limit Testing Analysis
                                                                                                                  • 1A41 Limit Testing Overview
                                                                                                                  • 1A42 Using the SVT Limit Testing VI
                                                                                                                    • 1A5 Integration
                                                                                                                      • 1A51 Introduction to Integration
                                                                                                                      • 1A52 Implementing Integration
                                                                                                                        • 1A521 Challenges when Integrating Vibration Data
                                                                                                                          • 1A53 Time-Domain Integration
                                                                                                                            • 1A531 Single-Shot Acquisition and Integration
                                                                                                                            • 1A532 Continuous Acquisition and Integration
                                                                                                                              • 1A54 Frequency-Domain Integration
                                                                                                                                • 1A6 Vibration-Level Measurements
                                                                                                                                  • 1A61 Measuring the Root Mean Square Level
                                                                                                                                    • 1A611 Single-Shot Buffered Acquisition
                                                                                                                                    • 1A612 Continuous Signal Acquisition
                                                                                                                                      • 1A62 Performing a Running RMS Level Measurement
                                                                                                                                      • 1A63 Computing the Peak Level
                                                                                                                                      • 1A64 Computing the Crest Factor
                                                                                                                                        • 1A7 Frequency Analysis
                                                                                                                                          • 1A71 FFT Fundamentals
                                                                                                                                            • 1A711 Number of Samples
                                                                                                                                            • 1A712 Frequency Resolution
                                                                                                                                            • 1A713 Maximum Resolvable Frequency
                                                                                                                                            • 1A714 Minimum Resolvable Frequency
                                                                                                                                            • 1A715 Number of Spectral Lines
                                                                                                                                            • 1A716 Relationship between Time-Domain and Frequency-Domain Specifications and Parameters
                                                                                                                                              • 1A72 Increasing Frequency Resolution
                                                                                                                                                • 1A721 Zoom FFT Analysis
                                                                                                                                                • 1A722 Frequency Resolution of the Zoom FFT VIs
                                                                                                                                                • 1A723 Zoom Measurement
                                                                                                                                                • 1A724 Zoom Settings
                                                                                                                                                • 1A725 Subset Analysis
                                                                                                                                                    • 1A8 Transient Analysis
                                                                                                                                                      • 1A81 Transient Analysis with the Sound and Vibration Toolkit
                                                                                                                                                      • 1A82 Performing an STFT vs Time
                                                                                                                                                        • 1A821 Selecting the FFT Block Size
                                                                                                                                                        • 1A822 Overlapping
                                                                                                                                                        • 1A823 Using the SVT STFT vs Time VI
                                                                                                                                                          • 1A83 Performing an STFT vs Rotational Speed
                                                                                                                                                            • 1A831 Converting the Pulse Train to Rotational Speed
                                                                                                                                                            • 1A832 STFT vs RPM
                                                                                                                                                              • 1A84 Measuring a Shock Response Spectrum
                                                                                                                                                                • 1A9 Waterfall Display
                                                                                                                                                                  • 1A91 Using the Display VIs
                                                                                                                                                                    • 1A911 Initializing the Display
                                                                                                                                                                    • 1A912 Sending Data to the Display
                                                                                                                                                                    • 1A913 Waterfall Display for Frequency Analysis
                                                                                                                                                                    • 1A914 Waterfall Display for Transient Analysis
                                                                                                                                                                    • 1A915 Waterfall Display for Octave Spectra
                                                                                                                                                                        • 1A10 Swept-Sine Measurements
                                                                                                                                                                          • 1A101 Swept-Sine Overview
                                                                                                                                                                          • 1A102 Choosing Swept-Sine vs FFT Measurements
                                                                                                                                                                          • 1A103 Taking a Swept-Sine Measurement
                                                                                                                                                                          • 1A104 Swept-Sine Measurement Example
                                                                                                                                                                              • Bibliography
                                                                                                                                                                              • Related Titles
                                                                                                                                                                                  • 53191ch2
                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                    • Chapter 2 Signal Conditioning and Modification
                                                                                                                                                                                      • Summary
                                                                                                                                                                                      • 21 Introduction
                                                                                                                                                                                      • 22 Amplifiers
                                                                                                                                                                                        • 221 Operational Amplifier
                                                                                                                                                                                        • 222 Use of Feedback in Opamp
                                                                                                                                                                                        • 223 Voltage Current and Power Amplifiers
                                                                                                                                                                                          • 2231 Charge Amplifiers
                                                                                                                                                                                            • 224 Instrumentation Amplifiers
                                                                                                                                                                                              • 2241 Differential Amplifier
                                                                                                                                                                                              • 2242 Common Mode
                                                                                                                                                                                                • 225 Amplifier Performance Ratings
                                                                                                                                                                                                  • 2251 Common-Mode Rejection Ratio
                                                                                                                                                                                                    • 226 Component Interconnection
                                                                                                                                                                                                      • 2261 Impedance Characteristics
                                                                                                                                                                                                      • 2262 Cascade Connection of Devices
                                                                                                                                                                                                      • 2263 AC-Coupled Ampliers
                                                                                                                                                                                                          • 23 Analog Filters
                                                                                                                                                                                                            • 231 Passive Filters and Active Filters
                                                                                                                                                                                                              • 2311 Number of Poles
                                                                                                                                                                                                                • 232 Low-Pass Filters
                                                                                                                                                                                                                  • 2321 Low-Pass Butterworth Filter
                                                                                                                                                                                                                    • 233 High-Pass Filters
                                                                                                                                                                                                                    • 234 Band-Pass Filters
                                                                                                                                                                                                                      • 2341 Resonance-Type Band-Pass Filters
                                                                                                                                                                                                                        • 235 Band-Reject Filters
                                                                                                                                                                                                                          • 24 Modulators and Demodulators
                                                                                                                                                                                                                            • 241 Amplitude Modulation
                                                                                                                                                                                                                              • 2411 Modulation Theorem
                                                                                                                                                                                                                              • 2412 Side Frequencies and Side Bands
                                                                                                                                                                                                                                • 242 Application of Amplitude Modulation
                                                                                                                                                                                                                                  • 2421 Fault Detection and Diagnosis
                                                                                                                                                                                                                                    • 243 Demodulation
                                                                                                                                                                                                                                      • 25 Analog ndashDigital Conversion
                                                                                                                                                                                                                                        • 251 Digital-to-Analog Conversion
                                                                                                                                                                                                                                          • 2511 DAC Error Sources
                                                                                                                                                                                                                                            • 252 Analog-to-Digital Conversion
                                                                                                                                                                                                                                            • 253 Analog-to-Digital Converter Performance Characteristics
                                                                                                                                                                                                                                              • 2531 Resolution and Quantization Error
                                                                                                                                                                                                                                              • 2532 Monotonicity Nonlinearity and Offset Error
                                                                                                                                                                                                                                              • 2533 Analog-to-Digital Converter Conversion Rate
                                                                                                                                                                                                                                                • 254 Sample-and-Hold Circuitry
                                                                                                                                                                                                                                                • 255 Digital Filters
                                                                                                                                                                                                                                                  • 2551 Software Implementation and Hardware Implementation
                                                                                                                                                                                                                                                      • 26 Bridge Circuits
                                                                                                                                                                                                                                                        • 261 Wheatstone Bridge
                                                                                                                                                                                                                                                        • 262 Constant-Current Bridge
                                                                                                                                                                                                                                                        • 263 Bridge Amplifiers
                                                                                                                                                                                                                                                          • 2631 Half-Bridge Circuits
                                                                                                                                                                                                                                                            • 264 Impedance Bridges
                                                                                                                                                                                                                                                              • 2641 Owen Bridge
                                                                                                                                                                                                                                                              • 2642 Wien-Bridge Oscillator
                                                                                                                                                                                                                                                                  • 27 Linearizing Devices
                                                                                                                                                                                                                                                                    • 271 Linearization by Software
                                                                                                                                                                                                                                                                    • 272 Linearization by Hardware Logic
                                                                                                                                                                                                                                                                    • 273 Analog Linearizing Circuitry
                                                                                                                                                                                                                                                                    • 274 Offsetting Circuitry
                                                                                                                                                                                                                                                                    • 275 Proportional-Output Circuitry
                                                                                                                                                                                                                                                                      • 2751 Curve-Shaping Circuitry
                                                                                                                                                                                                                                                                          • 28 Miscellaneous Signal Modification Circuitry
                                                                                                                                                                                                                                                                            • 281 Phase Shifters
                                                                                                                                                                                                                                                                            • 282 Voltage-to-Frequency Converter
                                                                                                                                                                                                                                                                            • 283 Frequency-to-Voltage Converter
                                                                                                                                                                                                                                                                            • 284 Voltage-to-Current Converters
                                                                                                                                                                                                                                                                            • 285 Peak-Hold Circuits
                                                                                                                                                                                                                                                                              • 29 Signal Analyzers and Display Devices
                                                                                                                                                                                                                                                                                • 291 Signal Analyzers
                                                                                                                                                                                                                                                                                • 292 Oscilloscopes
                                                                                                                                                                                                                                                                                  • 2921 Triggering
                                                                                                                                                                                                                                                                                  • 2922 Lissajous Patterns
                                                                                                                                                                                                                                                                                  • 2923 Digital Oscilloscopes
                                                                                                                                                                                                                                                                                      • Bibliography
                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                          • 53191ch3
                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                            • Chapter 3 Vibration Testing
                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                              • 31 Introduction
                                                                                                                                                                                                                                                                                              • 32 Representation of a Vibration Environment
                                                                                                                                                                                                                                                                                                • 321 Test Signals
                                                                                                                                                                                                                                                                                                  • 3211 Stochastic vs Deterministic Signals
                                                                                                                                                                                                                                                                                                    • 322 Deterministic Signal Representation
                                                                                                                                                                                                                                                                                                      • 3221 Single-Frequency Signals
                                                                                                                                                                                                                                                                                                      • 3222 Sine Sweep
                                                                                                                                                                                                                                                                                                      • 3223 Sine Dwell
                                                                                                                                                                                                                                                                                                      • 3224 Decaying Sine
                                                                                                                                                                                                                                                                                                      • 3225 Sine Beat
                                                                                                                                                                                                                                                                                                      • 3226 Sine Beat with Pauses
                                                                                                                                                                                                                                                                                                      • 3227 Multifrequency Signals
                                                                                                                                                                                                                                                                                                      • 3228 Actual Excitation Records
                                                                                                                                                                                                                                                                                                      • 3229 Simulated Excitation Signals
                                                                                                                                                                                                                                                                                                        • 323 Stochastic Signal Representation
                                                                                                                                                                                                                                                                                                          • 3231 Ergodic Random Signals
                                                                                                                                                                                                                                                                                                          • 3232 Stationary Random Signals
                                                                                                                                                                                                                                                                                                          • 3233 Independent and Uncorrelated Signals
                                                                                                                                                                                                                                                                                                          • 3234 Transmission of Random Excitations
                                                                                                                                                                                                                                                                                                            • 324 Frequency-Domain Representations
                                                                                                                                                                                                                                                                                                              • 3241 Fourier Spectrum Method
                                                                                                                                                                                                                                                                                                              • 3242 Power Spectral Density Method
                                                                                                                                                                                                                                                                                                                • 325 Response Spectrum
                                                                                                                                                                                                                                                                                                                  • 3251 Displacement Velocity and Acceleration Spectra
                                                                                                                                                                                                                                                                                                                  • 3252 Response-Spectra Plotting Paper
                                                                                                                                                                                                                                                                                                                  • 3253 Zero-Period Acceleration
                                                                                                                                                                                                                                                                                                                  • 3254 Uses of Response Spectra
                                                                                                                                                                                                                                                                                                                    • 326 Comparison of Various Representations
                                                                                                                                                                                                                                                                                                                      • 33 Pretest Procedures
                                                                                                                                                                                                                                                                                                                        • 331 Purpose of Testing
                                                                                                                                                                                                                                                                                                                        • 332 Service Functions
                                                                                                                                                                                                                                                                                                                          • 3321 Active Equipment
                                                                                                                                                                                                                                                                                                                          • 3322 Passive Equipment
                                                                                                                                                                                                                                                                                                                          • 3323 Functional Testing
                                                                                                                                                                                                                                                                                                                            • 333 Information Acquisition
                                                                                                                                                                                                                                                                                                                              • 3331 Interface Details
                                                                                                                                                                                                                                                                                                                              • 3332 Effect of Neglecting Interface Dynamics
                                                                                                                                                                                                                                                                                                                              • 3333 Effects of Damping
                                                                                                                                                                                                                                                                                                                              • 3334 Effects of Inertia
                                                                                                                                                                                                                                                                                                                              • 3335 Effect of Natural Frequency
                                                                                                                                                                                                                                                                                                                              • 3336 Effect of Excitation Frequency
                                                                                                                                                                                                                                                                                                                              • 3337 Other Effects of Interface
                                                                                                                                                                                                                                                                                                                                • 334 Test-Program Planning
                                                                                                                                                                                                                                                                                                                                  • 3341 Testing of Cabinet-Mounted Equipment
                                                                                                                                                                                                                                                                                                                                    • 335 Pretest Inspection
                                                                                                                                                                                                                                                                                                                                      • 34 Testing Procedures
                                                                                                                                                                                                                                                                                                                                        • 341 Resonance Search
                                                                                                                                                                                                                                                                                                                                        • 342 Methods of Determining Frequency-Response Functions
                                                                                                                                                                                                                                                                                                                                          • 3421 Fourier Transform Method
                                                                                                                                                                                                                                                                                                                                          • 3422 Spectral Density Method
                                                                                                                                                                                                                                                                                                                                          • 3423 Harmonic Excitation Method
                                                                                                                                                                                                                                                                                                                                            • 343 Resonance-Search Test Methods
                                                                                                                                                                                                                                                                                                                                              • 3431 Hammer (Bump) Test and Drop Test
                                                                                                                                                                                                                                                                                                                                              • 3432 Pluck Test
                                                                                                                                                                                                                                                                                                                                              • 3433 Shaker Tests
                                                                                                                                                                                                                                                                                                                                                • 344 Mechanical Aging
                                                                                                                                                                                                                                                                                                                                                  • 3441 Equivalence for Mechanical Aging
                                                                                                                                                                                                                                                                                                                                                  • 3442 Excitation-Intensity Equivalence
                                                                                                                                                                                                                                                                                                                                                  • 3443 Dynamic-Excitation Equivalence
                                                                                                                                                                                                                                                                                                                                                  • 3444 Cumulative Damage Theory
                                                                                                                                                                                                                                                                                                                                                    • 345 Test-Response Spectrum Generation
                                                                                                                                                                                                                                                                                                                                                    • 346 Instrument Calibration
                                                                                                                                                                                                                                                                                                                                                    • 347 Test-Object Mounting
                                                                                                                                                                                                                                                                                                                                                    • 348 Test-Input Considerations
                                                                                                                                                                                                                                                                                                                                                      • 3481 Test Nomenclature
                                                                                                                                                                                                                                                                                                                                                      • 3482 Testing with Uncorrelated Excitations
                                                                                                                                                                                                                                                                                                                                                      • 3483 Symmetrical Rectilinear Testing
                                                                                                                                                                                                                                                                                                                                                      • 3484 Geometry vs Dynamics
                                                                                                                                                                                                                                                                                                                                                      • 3485 Some Limitations
                                                                                                                                                                                                                                                                                                                                                      • 3486 Testing Black Boxes
                                                                                                                                                                                                                                                                                                                                                      • 3487 Phasing of Excitations
                                                                                                                                                                                                                                                                                                                                                      • 3488 Testing a Gray or White Box
                                                                                                                                                                                                                                                                                                                                                      • 3489 Overtesting in Multitest Sequences
                                                                                                                                                                                                                                                                                                                                                          • 35 Some Practical Information
                                                                                                                                                                                                                                                                                                                                                            • 351 Random Vibration Test Example
                                                                                                                                                                                                                                                                                                                                                            • 352 Vibration Shakers and Control Systems
                                                                                                                                                                                                                                                                                                                                                              • Bibliography
                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                  • 53191ch4
                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                    • Chapter 4 Experimental Modal Analysis
                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                      • 41 Introduction
                                                                                                                                                                                                                                                                                                                                                                      • 42 Frequency-Domain Formulation
                                                                                                                                                                                                                                                                                                                                                                        • 421 Transfer-Function Matrix
                                                                                                                                                                                                                                                                                                                                                                        • 422 Principle of Reciprocity
                                                                                                                                                                                                                                                                                                                                                                          • 43 Experimental Model Development
                                                                                                                                                                                                                                                                                                                                                                            • 431 Extraction of the Time-Domain Model
                                                                                                                                                                                                                                                                                                                                                                              • 44 Curve Fitting of Transfer Functions
                                                                                                                                                                                                                                                                                                                                                                                • 441 Problem Identification
                                                                                                                                                                                                                                                                                                                                                                                • 442 Single- and Multi-Degree-of-Freedom Techniques
                                                                                                                                                                                                                                                                                                                                                                                • 443 Single-Degree-of-Freedom Parameter Extraction in the Frequency Domain
                                                                                                                                                                                                                                                                                                                                                                                  • 4431 Circle-Fit Method
                                                                                                                                                                                                                                                                                                                                                                                    • Case of Viscous Damping
                                                                                                                                                                                                                                                                                                                                                                                    • Case of Hysteretic Damping
                                                                                                                                                                                                                                                                                                                                                                                      • 4432 Peak-Picking Method
                                                                                                                                                                                                                                                                                                                                                                                        • 444 Multi-Degree of Freedom Curve Fitting
                                                                                                                                                                                                                                                                                                                                                                                          • 4441 Formulation of the Method
                                                                                                                                                                                                                                                                                                                                                                                            • 445 A Comment on Static Modes and Rigid-Body Modes
                                                                                                                                                                                                                                                                                                                                                                                            • 446 Residue Extraction
                                                                                                                                                                                                                                                                                                                                                                                              • 45 Laboratory Experiments
                                                                                                                                                                                                                                                                                                                                                                                                • 451 Lumped-Parameter System
                                                                                                                                                                                                                                                                                                                                                                                                  • 4511 Frequency-Domain Test
                                                                                                                                                                                                                                                                                                                                                                                                  • 4512 Time-Domain Tests
                                                                                                                                                                                                                                                                                                                                                                                                    • 452 Distributed-Parameter System
                                                                                                                                                                                                                                                                                                                                                                                                      • 46 Commercial EMA Systems
                                                                                                                                                                                                                                                                                                                                                                                                        • 461 System Configuration
                                                                                                                                                                                                                                                                                                                                                                                                          • 4611 FFT Analysis Options
                                                                                                                                                                                                                                                                                                                                                                                                          • 4612 Modal Analysis Components
                                                                                                                                                                                                                                                                                                                                                                                                              • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                  • 53191ch5
                                                                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                    • Chapter 5 Mechanical Shock
                                                                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                      • 51 Definitions
                                                                                                                                                                                                                                                                                                                                                                                                                        • 511 Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 512 Simple (or Perfect) Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 513 Half-Sine Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 514 Versed-Sine (or Haversine) Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 515 Terminal Peak Sawtooth Shock or Final Peak Sawtooth Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 516 Rectangular Shock
                                                                                                                                                                                                                                                                                                                                                                                                                          • 5161 Trapezoidal Shock
                                                                                                                                                                                                                                                                                                                                                                                                                              • 52 Description in the Time Domain
                                                                                                                                                                                                                                                                                                                                                                                                                              • 53 Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                • 531 Need
                                                                                                                                                                                                                                                                                                                                                                                                                                • 532 Shock Response Spectrum Definition
                                                                                                                                                                                                                                                                                                                                                                                                                                • 533 Response of a Linear One-Degree-of-Freedom System
                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5331 Shock Defined by a Force
                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5332 Shock Defined by an Acceleration
                                                                                                                                                                                                                                                                                                                                                                                                                                    • 534 Definitions
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5341 Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5342 Absolute Acceleration Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5343 Relative Displacement Shock Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5344 Primary Positive Shock Response Spectrum or Initial Positive Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5345 Primary (or Initial) Negative Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5346 Secondary (or Residual) Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5347 Positive (or Maximum Positive) Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5348 Negative (or Maximum Negative) Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5349 Maximax Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53410 Choice of Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                        • 535 Standardized Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5351 Definition
                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5352 Standardized Shock Response Spectra of Simple Shocks
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53521 Half-Sine Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53522 Versed Sine Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53523 Terminal Peak Sawtooth Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53524 Rectangular Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53525 Trapezoidal Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 536 Choice of Damping
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 537 Shock Response Spectra Domains
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 538 Algorithms for Calculation of the Shock Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 539 Choice of the Digitization Frequency of the Signal
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5310 Use of Shock Response Spectra for the Study of Systems with Several Degrees of Freedom
                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 54 Pyroshocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 55 Use of Shock Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 551 Severity Comparison of Several Shocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 552 Test Specification Development from Real Environment Data
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5521 Synthesis of Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5522 Nature of the Specification
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5523 Choice of Shape
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5524 Amplitude
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5525 Duration
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5526 Difficulties
                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 56 Standards
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 561 Types of Standards
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 562 Installation Conditions of Test Item
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 563 Uncertainty Factor
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 564 Bump Test
                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 57 Damage Boundary Curve
                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 571 Definition
                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 572 Analysis of Test Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 58 Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 581 Main Types
                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 582 Impact Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5821 Universal Shock-Test Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 58211 Impact Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 58212 Impulse Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 583 Shock Simulators (Programmers)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5831 Half-Sine Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58311 Shock Duration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58312 Impact Velocity
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58313 Maximum Deformation of the Shock Simulator (Programmer)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58314 Shock Amplitude
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58315 Characteristics of the Target
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5832 Terminal Peak Sawtooth Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5833 Rectangular Pulse ndash Trapezoidal Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5834 Universal Shock Simulator (Programmer)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 58341 Generating a Half-Sine Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 58342 Generating a Terminal Peak Sawtooth Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 58343 Trapezoidal Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 584 Limitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5841 Limitations of the Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5842 Limitations of Shock Simulators
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 585 Pneumatic Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 586 High Impact Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5861 Lightweight High Impact Shock Machine
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5862 Medium Weight High Impact Shock Machine
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 587 Specific Test Facilities
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 59 Generation of Shock Using Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 591 Principle Behind the Generation of a Simple Shape Signal versus Time
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 592 Main Advantages
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 593 Pre- and Postshocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5931 Requirements
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5932 Solutions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 59321 Optimized Pre- and Postpulses
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5933 Incidence on the Shock Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 594 Limitations of Electrodynamic Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5941 Mechanical Limitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 59411 Abacuses
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5942 Electronic Limitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 595 The Use of Electrohydraulic Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 510 Control by a Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 5101 Principle
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 5102 Principal Shapes of Elementary Signals
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 51021 Decaying Sinusoid
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 51022 ZERD Function
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 51023 WAVSIN Waveform
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 5103 Comparison of WAVSIN SHOC Waveforms and Decaying Sinusoid
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 5104 Criticism of Control by a Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 511 Pyrotechnic Shock Simulation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5111 Simulation Using Pyrotechnic Facilities
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5112 Simulation Using Metal-to-Metal Impact
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5113 Simulation Using Electrodynamic Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5114 Simulation Using Conventional Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53191ch6
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Chapter 6 Machine Condition Monitoring and Fault Diagnostics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 61 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 62 Machinery Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 621 Causes of Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 622 Types of Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 623 Frequency of Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 63 Basic Maintenance Strategies
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 631 Run-to-Failure (Breakdown) Maintenance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 632 Scheduled (Preventative) Maintenance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 633 Condition-Based (Predictive Proactive Reliability Centered On-Condition) Maintenance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 64 Factors Which Influence Maintenance Strategy
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 65 Machine Condition Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 651 Periodic Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 652 Continuous Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 66 Transducer Selection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 661 Noncontact Displacement Transducers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 662 Velocity Transducers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 663 Acceleration Transducers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 67 Transducer Location
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 68 Recording and Analysis Instrumentation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 681 Vibration Meters
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 682 Data Collectors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 683 Frequency-Domain Analyzers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 684 Time-Domain Instruments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 685 Tracking Analyzers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 69 Display Formats and Analysis Tools
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 691 Time Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6911 Time-Waveform Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6912 Time-Waveform Indices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6913 Time-Synchronous Averaging
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6914 Negative Averaging
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6915 Orbits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6916 Probability Density Functions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6917 Probability Density Moments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 692 Frequency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6921 Band-Pass Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6922 Shock Pulse (Spike Energy)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6923 Enveloped Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6924 Signature Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6925 Cascades (Waterfall Plots)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6926 Masks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6927 Frequency-Domain Indices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 693 Modal Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 694 Quefrency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 610 Fault Detection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 6101 Standards
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61011 Standards Based on Machinery Type
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61012 Standards Based on Vibration Severity
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 6102 Acceptance Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 61021 Statistical Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 6103 Frequency-Domain Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61031 Limited Band Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61032 Constant Bandwidth Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61033 Constant Percentage Bandwidth Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 611 Fault Diagnostics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 6111 Forcing Functions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61111 Unbalance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61112 Misalignment
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61113 Mechanical Looseness
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61114 Soft Foot
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61115 Rubs
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61116 Resonances
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61117 Oil Whirl
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61118 Oil Whip
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61119 Structural Vibrations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 611110 Foundation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 6112 Specific Machine Components
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 61121 Damaged or Worn Rolling-Element Bearings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 61122 Damaged or Worn Gears
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 6113 Specific Machine Types
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61131 Pumps
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61132 Fans
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61133 Electric Motors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61134 Steam and Gas Turbines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61135 Compressors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61136 Reciprocating Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 6114 Advanced Fault Diagnostic Techniques
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 53191ch7
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • Chapter 7 Vibration-Based Tool Condition Monitoring Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 71 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 72 Mechanics of Turning
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 721 General Terms
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 722 Chatter Vibrations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 723 Tool Wear
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7231 Tool Failure Mechanisms
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7232 Tool Failure Modes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7233 Tool Wear Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7234 Tool Wear Stages
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 73 Vibration Signal Recording
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 731 Direct and Indirect Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 732 Sensor Requirements for Tool Wear Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 733 Force Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7331 Direct Measurement Dynamometers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7332 Indirect Force Sensors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7333 Piezoelectric Strain Sensors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7334 Resistance Strain Gauges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7335 Customized Force Sensors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 734 Acceleration Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 735 Acoustic Emission Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 736 Sensor Comparisons
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 74 Signal Processing for Sensor-Based Tool Condition Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 741 Feature Extraction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7411 Time Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7412 Frequency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7413 Statistical Processing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7414 TimendashFrequency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 742 Feature Selection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 75 Wear ModelDecision-Making for Sensor-Based Tool Condition Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 751 Trending Threshold
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 752 Neural Networks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7521 Unsupervised Networks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7522 Supervised Networks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 753 Fuzzy Logic
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 754 Other Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 76 Conclusion
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53191ch8
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Chapter 8 Fault Diagnosis of Helicopter Gearboxes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 81 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 82 Abnormality Scaling
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 83 The Structure-Based Connectionist Network
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 84 Sensor Location Selection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 841 Coverage Index
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 842 Overlap Index
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 843 Monitoring Effectiveness
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 85 A Case Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 851 Structural and Featural Influences
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 852 Evaluation of Influences
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 853 Fault Detection Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 854 Fault Diagnostic Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 8541 Faulty Subsystem Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 8542 Faulty Component Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 855 Sensor Location Evaluation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 856 Sensor Location Validation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 86 Conclusion
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 53191ch9
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Chapter 9 Vibration Suppression and Monitoring in Precision Motion Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 91 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 92 Mechanical Design to Minimize Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 921 Stability and Static Determinacy of Machine Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 922 Two-Dimensional Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 923 Three-Dimensional Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 93 Adaptive Notch Filter
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 931 Fast Fourier Transform
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 932 Simulation and Experiments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 94 Real-Time Vibration Analyzer
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 941 Learning Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 942 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 943 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 944 Experiments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 9441 Input Variables mdash the Evaluation Criteria
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 94411 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 94412 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 9442 Evaluation Rules
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 94421 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 94422 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 9443 Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 94431 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 94432 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 95 Practical Insights and Case Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 96 Conclusions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 53191ch10
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Chapter 10 Vibration and Shock Problems of Civil Engineering Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 101 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 102 Earthquake-Induced Vibration of Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1021 Seismicity and Ground Motions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1022 Influence of Local Site Conditions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1023 Response of Structures to Ground Motions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1024 Dynamic Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10241 Equations of Motion for Linear Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10242 Equations of Motion for Linear Multiple-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1025 Earthquake Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10251 Elastic Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10252 Smoothed Design Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10253 Ductility-Modified Response Spectrum Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1026 Design Philosophy and the Code Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10261 Performance-Based Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1027 Analysis Options for Earthquake Effects
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10271 Dynamic Time History Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10272 Response Spectrum Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 102721 Response Spectrum Analysis of Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 102722 Response Spectrum Analysis of Multi-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10273 Equivalent Static Analysis (Force-Based Approach)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10274 Displacement-Based Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1028 SoilndashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1029 Active and Passive Control Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 10210 Worked Examples
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 103 Dynamic Effects of Wind Loading on Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1031 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1032 Wind Speed
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1033 Design Structures for Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10331 Types of Wind Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10332 Design Criteria
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10333 Static Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1034 Along and Across-Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10341 Along-Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10342 Across-Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1035 Wind Tunnel Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1036 Comfort Criteria Human Response to Building Motion
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1037 Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1038 Comparison with Earthquake Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 104 Vibrations Due to Fluid ndashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1041 Added Mass and Inertial Coupling
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1042 Wave-Induced Vibration of Structure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 105 Blast Loading and Blast Effects on Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1051 Explosions and Blast Phenomenon
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1052 Explosive Air-Blast Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10521 Blast Wave Scaling Laws
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10522 Prediction of Blast Pressure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1053 Gas Explosion Loading and Effect of Internal Explosions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1054 Structural Response to Blast Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10541 Elastic Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10542 Elasto-Plastic Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1055 Material Behaviors at High Strain Rate
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10551 Dynamic Properties of Concrete under High Strain Rates
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10552 Dynamic Properties of Reinforcing Steel under High Strain Rates
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1056 Failure Modes of Blast-Loaded Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10561 Global Structural Behavior
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10562 Localized Structural Behavior
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10563 PressurendashImpulse ( PndashI ) Diagrams
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1057 Blast WavendashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1058 Effect of Ground Shocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10581 Loads from Air-Induced Ground Shock
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10582 Loads from Direct Ground Shock
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1059 Technical Design Manuals for Blast-Resistant Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 10510 Computer Programs for Blast and Shock Effects
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 106 Impact Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1061 Structural Impact between Two Bodies mdash Hard Impact and Soft Impact
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1062 Example mdash Aircraft Impact
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 107 Floor Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1071 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1072 Types of Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10721 Walking
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10722 Rhythmic Activities
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10723 Mechanical Equipment
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10724 Analysis Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1073 Natural Frequency of Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10731 Computing the Natural Frequency
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10732 Computing Deflection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10733 Damping
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10734 Resonance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1074 Vibration Caused by Walking
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10741 Minimum Natural Frequency
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1075 Design for Rhythmic Excitation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10751 Harmonics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10752 Minimum Natural Frequency
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1076 Example mdash Vibration Analysis of a Reinforced Concrete Floor
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 53191ch11
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Chapter 11 Seismic Base Isolation and Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 111 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1111 From Ductility Design to Base Isolation and Control Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1112 The Importance of Reducing Seismic Input and Response
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 112 Seismic Base Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1121 Historical Development of Base Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1122 Basic Principle
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1123 Issues in Seismic Base Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11231 Performance Criteria
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11232 Type of Structure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11233 Site Characteristics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11234 Retrofit Issues
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11235 Design of Building Services
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11236 Expected Life of Isolator
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1124 Seismic Isolation Devices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11241 Laminated Rubber Bearings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11242 Lead Rubber Bearing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11243 Friction-Based Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11244 Other Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1125 Design of Isolation Devices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11251 High-Damping Rubber Bearing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112511 Stability against Buckling
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112512 Stability against Roll Out
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11252 Lead Rubber Bearings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112521 Design of Lead Plug
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112522 Design of Laminated Rubber Bearing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11253 Design of Friction Pendulum System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1126 Verification of Properties of Isolation Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11261 Tests for Isolation Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 112611 System Characterization Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 112612 Prototype Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 112613 Quality Control Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11262 Uniform Building Code Recommendations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112621 Units Dependent on Loading Rates
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112622 Units Dependent on Bilateral Load
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112623 System Adequacy
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1127 Analysis of Base-Isolated Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11271 Modeling of a Superstructure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11272 Modeling of Isolation System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11273 Static Analysis Procedure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11274 Dynamic Analysis Procedure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 112741 Response Spectrum Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 112742 Time-History Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11275 Software for Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1128 Experimental Methods for Isolated Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1129 Implementation of Seismic Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11291 New Construction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112911 Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112912 Bridges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11292 Seismic Retrofit
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112921 Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112922 Bridges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11293 Other Implementations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 11210 Performance during Past Earthquakes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 112101 Performance of Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 112102 Performance of Bridges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 113 Seismic Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1131 Historical Development of Seismic Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1132 Basic Principles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11321 Passive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11322 Active Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11323 Semiactive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11324 Hybrid Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11325 Categorization of Basic Principles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1133 Important Issues in Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11331 SoilndashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11332 DevicendashStructure Interaction and Time Delay
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11333 Design Guidelines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1134 Vibration-Control Devices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11341 Passive Control Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113411 Metallic Yielding Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113412 Friction Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113413 Viscoelastic Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113414 Viscous Fluid Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113415 Tuned Mass Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11342 Active Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113421 Electromagnetic Actuator
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113422 Hydraulic Actuators
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11343 Semiactive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113431 Variable-Orifice Hydraulic Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113432 Controllable Fluid Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113433 Controllable Friction Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11344 Hybrid Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1135 Control Algorithm
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11351 Active Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11352 Semiactive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113521 Common Control Schemes for Controllable Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113522 Special Control Schemes for Controllable Damper
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1136 Experimental Performance Verification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11361 Shaking Table Tests of a Flexible Structural Model with TMD AMD and ATMD
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11362 Substructure Hybrid Test
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113621 Hybrid Tests Using Hydraulic Actuator
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113622 Hybrid Tests Using Shaking Table
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113623 Hybrid Tests Using Inertia-Force-Driven Loading System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1137 Implementations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11371 Semiactive Control of Full-Scale Structures Using Variable Joint Damper System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113711 Background of Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113712 Test System Set Up
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113713 Control Algorithm
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113714 Test Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11372 Application of Structural Control Technologies to Seismic Retrofit of a Cable-Stayed Bridge
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113721 Background of Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113722 Basic Concept of Seismic Retrofit
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113723 Modal Shape Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113724 Time-History Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113725 Soil ndash Structure Interaction Effect
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113726 Semiactive Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53191ch12
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Chapter 12 Seismic Random Vibration of Long-Span Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 121 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1211 Basic Concepts of Random Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12111 Stationary Random Process
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12112 Nonstationary Random Process
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1212 Three Methods for Structural Seismic Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12121 Response Spectrum Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12122 Time-History Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12123 Random Vibration Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 121231 Davenport Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 121232 Vanmarcke Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 12124 Comparisons of the Three Seismic-Analysis Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 122 Seismic Random-Excitation Fields
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1221 Power Spectral Density of Spatially Varying Ground Acceleration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1222 Several Coherence Models
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12221 FengndashHu Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12222 Harichandran ndashVanmarcke Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12223 LohndashYeh Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12224 OliveirandashHaondashPenzien Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12225 LucondashWong Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12226 QundashWangndashWang Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1223 Generation of Ground Acceleration Power Spectral Density Curves from Acceleration Response Spectrum Curves
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12231 Kaul Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12232 Iteration Scheme
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1224 Seismic Equations of Motion of Long-Span Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1225 Seismic Waves and Their Geometrical Expressions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 123 Pseudoexcitation Method for Structural Random Vibration Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1231 Structures Subjected to Stationary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12311 Single Stationary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12312 Multiple Stationary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1232 Structures Subjected to Nonstationary Random Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12321 Structures Subjected to Uniformly Modulated Evolutionary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 123211 Single Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 123212 Multiple Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12322 Structures Subjected to Nonuniformly Modulated Evolutionary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 123221 Single Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 123222 Multiple Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1233 Precise Integration Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12331 Precise Integration of Exponential Matrices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12332 Particular Solutions and Precise Integration Formulas for Various Forms of Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 123321 Linear Loading Form (HPD-L Form)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 123322 Sinusoidal Loading Form (HPD-S Form)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 123323 Exponentially Decaying Sinusoidal Loading Form (HPD-E Form)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 124 Long-Span Structures Subjected to Stationary Random Ground Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1241 The Solution of Equations of Motion Using the Pseudoexcitation Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1242 Numerical Comparisons with Other Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12421 Song-Hua-Jiang Suspension Bridge
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 124211 All Supports Move Uniformly
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 124212 Wave Passage Effect Is Taken into Account
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 124213 Wave-Passage Effect and Incoherence Effect Are Jointly Taken into Account
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 12422 San Joaquin Concrete Bridge
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 125 Long-Span Structures Subjected to Nonstationary Random Ground Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1251 Modulation Functions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1252 The Formulas for Nonstationary Multiexcitation Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1253 Expected Extreme Values of Nonstationary Random Processes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1254 Numerical Comparisons with the Corresponding Stationary Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 126 Conclusions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Related Titles
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                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Chapter 13 Seismic Qualification of Equipment
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 131 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 132 Distribution Qualification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1321 Drive-Signal Generation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1322 Distribution Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1323 Test Procedures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 133 Seismic Qualification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1331 Stages of Seismic Qualification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1332 Test Preliminaries
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1333 Single-Frequency Testing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1334 Multifrequency Testing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1335 Generation of RRS Specifications
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 53191ch14
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Chapter 14 Human Response to Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 141 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 142 Vibration Excitations on Humans
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1421 Excitation Characteristics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 143 Human Response to Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1431 Vibration Perception
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1432 Frequency Weighting Curve
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1433 Iso-Perception Curves
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1434 Detection Threshold Curve
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 144 Regulation of Human Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1441 Acceptable Vibration Levels in Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1442 Whole-Body Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1443 HandndashArm Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
Page 24: Vibration Monitoring, Testing, and Instrumentationpreview.kingborn.net › 646000 › d1a74678d91943e5ba1d5e... · The MEMS Handbook, Second Edition MEMS: Introduction and Fundamentals

122 Dynamics of Electromagnetic Shakers

Consider a single axis electromagnetic shaker (Figure 18) with a test object having a single natural

frequency of importance within the test frequency range The dynamic interactions between the shaker

and the test object give rise to two significant natural frequencies (and correspondingly two significant

resonances) These appear as peaks in the frequency response curve of the test setup Furthermore the

natural frequency (resonance) of the test package alone causes a ldquotroughrdquo or depression (antiresonance)

in the frequency response curve of the overall test setup To explain this characteristic consider the

dynamic model shown in Figure 19 The following mechanical parameters are defined for

Figure 19(a) m k and b are the mass stiffness and equivalent viscous damping constant respectively

of the test package and me ke and be are the corresponding parameters of the exciter (shaker) Also in

the equivalent electrical circuit of the shaker head as shown in Figure 19(b) the following electrical

parameters are defined Re and Le are the resistance and (leakage) inductance and kb is the back

electromotive force (back emf) of the linear motor Assuming that the gravitational forces are supported

FIGURE 18 Schematic sectional view of a typical electromagnetic shaker manufactured by Bruel and Kjaer

Denmark

Vibration Monitoring Testing and Instrumentation1-12

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copy 2007 by Taylor amp Francis Group LLC

by the static deflections of the flexible elements and that the displacements are measured from the static

equilibrium position we have the following system equations

Test object meuroy frac14 2kethy2 yeTHORN2 beth_y2 _yeTHORN eth119THORNShaker head me euroye frac14 fe thorn kethy2 yeTHORN thorn beth_y2 _yeTHORN2 key 2 be _ye eth120THORN

Electrical Lediedt

thorn Reie thorn kb _ye frac14 vethtTHORN eth121THORN

The electromagnetic force fe generated in the shaker head is a result of the interaction of the magnetic

field generated by the current ie with coil of the moving shaker head and the constant magnetic field

(stator) in which the head coil is located Here we have

fe frac14 kbie eth122THORNNote that v(t) is the voltage signal that is applied by the amplifier to the shaker coil ye is the displacement

of the shaker head and y is the displacement response of the test package

It is assumed that kb has consistent electrical and mechanical units (Vmsec and NA) Usually

the electrical time constant of the shaker is quite small compared with the primarily mechanical

time constants of the shaker and the test package In such cases the Ledie=dt term in Equation 121 may

be neglected Consequently the equations from Equation 119 through Equation 122 may be

expressed in the Laplace (frequency) domain with the Laplace variable s taking the place of the derivative

d=dt as

ethms2 thorn bsthorn kTHORNy frac14 ethbsthorn kTHORNye eth123THORN

FIGURE 19 Dynamic models of an electromagnetic shaker and a flexible test package (a) mechanical model

(b) electrical model

Vibration Instrumentation 1-13

53191mdash522007mdash1202mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

frac12mes2 thorn ethbthorn beTHORNsthorn ethkthorn keTHORN ye frac14 ethbsthorn kTHORNy thorn kb

Rev2

k2bs

Reye eth124THORN

It follows that the transfer function of the shaker head motion with respect to the excitation voltage is

given by

yevfrac14 kb

Re

DethsTHORNDdethsTHORN eth125THORN

where DethsTHORN is the characteristic function of the primary dynamics of the test object

DethsTHORN frac14 ms2 thorn bsthorn k eth126THORN

and DdethsTHORN is the characteristic function of the primary dynamic interactions between the shaker and thetest object

DcethsTHORN frac14 mmes4 thorn frac12methbe thorn bthorn boTHORN thornmeb s

3 thorn frac12methke thorn kTHORN thornmekthorn bethbe thorn boTHORN s2thorn frac12bke thorn ethbe thorn boTHORNk sthorn kke

eth127THORN

where

bo frac14 k2bRe

eth128THORN

It is clear that under low damping conditions DdethsTHORN will produce two resonances as it is fourth order in sand similarly DethsTHORN will produce one antiresonance (trough) corresponding to the resonance of the testobject Note that in the frequency domain s frac14 jv and hence the frequency response function given by

Equation 125 is in fact

yevfrac14 kb

Rb

DethjvTHORNDdethjvTHORN eth129THORN

The magnitude of this frequency response function for a typical test system is sketched in Figure 110

Note that this curve is for the ldquoopen-looprdquo case where there is no feedback from the shaker controller

In practice the shaker controller will be able

to compensate for the resonances and anti-

resonances to some degree depending on its

effectiveness

The main advantages of electromagnetic

shakers are their high frequency range of

operation their high degree of operating flexi-

bility and the high level of accuracy of the

generated shaker motion Faithful reproduction

of complex excitations is possible because of the

advanced electronics and control systems used in

this type of shakers Electromagnetic shakers are

not suitable for heavy-duty applications (large test

objects) however High test-input accelerations

are possible at high frequencies when electromag-

netic shakers are used but their displacement and

velocity capabilities are limited to low or

intermediate values (see Table 11)

100

10

1 10 100Excitation Frequency (Hz)

Antiresonance

Resonance

Shak

erD

ispl

acem

entM

agni

tude

Resonance

1000

FIGURE 110 Frequency response curve of a typical

electromagnetic shaker with a test object

Vibration Monitoring Testing and Instrumentation1-14

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copy 2007 by Taylor amp Francis Group LLC

1221 Transient Exciters

Other varieties of exciters are commonly used in

transient-type vibration testing In these tests

either an impulsive force or an initial excitation is

applied to the test object and the resulting

response is monitored The excitations and the

responses are ldquotransientrdquo in this case Hammer

test drop tests and pluck tests fall into this

category For example a hammer test may be

conducted by hitting the object with an instru-

mented hammer and then measuring the response

of the object The hammer has a force sensor at its

tip as sketched in Figure 111 A piezoelectric or

strain-gage type force sensor may be used More

sophisticated hammers have impedance heads in

place of force sensors An impedance head

measures force and acceleration simultaneously

The results of a hammer test will depend on many

factors for example the dynamics of the hammer

body how firmly the hammer is held during the

impact how quickly the impact is applied and

whether there are multiple impacts

13 Control System

The two primary functions of the shaker control system in vibration testing are (1) to guarantee that the

specified excitation is applied to the test object and (2) to ensure that the dynamic stability (motion

constraints) of the test setup is preserved An operational block diagram illustrating these control

functions is given in Figure 112 The reference input to the control system represents the desired

excitation force that should be applied to the test object In the absence of any control however the force

reaching the test object will be distorted primarily because of (1) dynamic interactions and

nonlinearities of the shaker the test table the mounting fixtures the auxiliary instruments and the test

object itself (2) noise and errors in the signal generator amplifiers filters and other equipment and (3)

external loads and disturbances acting on the test object and other components (for example external

restraints aerodynamic forces friction) To compensate for these distorting factors response

measurements (displacements velocities acceleration and so on) are made at various locations in the

test setup and are used to control the system dynamics In particular the responses of the shaker the test

table and the test object are measured These responses are used to compare the actual excitation felt by

FIGURE 111 An instrumented hammer used in bump

tests or hammer tests

ExcitationInput

(Reference)

Feedback Paths

DriveSignal

ShakerResponse

TestTable

TestObject

Test ObjectResponse

Test TableResponseExciter

(Shaker)(Ram)

Controllerand

Amplifier

FIGURE 112 Operational block diagram illustrating a general shaker control system

Vibration Instrumentation 1-15

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copy 2007 by Taylor amp Francis Group LLC

the test object at the shaker interface with the desired (specified) input The drive signal to the shaker is

modified depending on the error that is present

Two types of control are commonly employed in shaker apparatus simple manual control and

complex automatic control Manual control normally consists of simple open-loop trial-and-error

methods of manual adjustments (or calibration) of the control equipment to obtain a desired dynamic

response The actual response is usually monitored (on an oscilloscope or frequency analyzer screen for

example) during manual-control operations The pretest adjustments in manual control can be very

time-consuming as a result the test object might be subjected to overtesting which could produce

cumulative damage is undesirable and could defeat the test purpose Furthermore the calibration

procedure for the experimental setup must be repeated for each new test object

The disadvantages ofmanual control suggest that automatic control is desirable in complex test schemes

in which high accuracy of testing is desired The first step of automatic control involves automatic

measurement of the system response using control sensors and transducers The measurement is then fed

back into the control system which instantaneously determines the best drive signal to actuate the shaker

in order to get the desired excitation This may be done by either analog or digital methods

Primitive control systems require an accurate mathematical description of the test object This

dependency of the control system on the knowledge of test-object dynamics is clearly undesirable

Performance of a good control system should not be considerably affected by the dynamic interactions

and nonlinearities of the test object or by the nature of the excitation Proper selection of feedback signals

and control-system components can reduce such effects and will make the system robust

In the response-spectrum method of vibration testing it is customary to use displacement control at

low frequencies velocity control at intermediate frequency and acceleration control at high frequencies

This necessitates feedback of displacement velocity and acceleration responses Generally however the

most important feedback is the velocity feedback In sine-sweep tests the shaker velocity must change

steadily over the frequency band of interest In particular the velocity control must be precise near the

resonances of the test object Velocity (speed) feedback has a stabilizing effect on the dynamics which is

desirable This effect is particularly useful in ensuring stability in motion when testing is done near

resonances of lightly damped test objects On the contrary displacement (position) feedback can have a

destabilizing effect on some systems particularly when high feedback gains are used

The controller usually consists of various instruments equipment and computation hardware and

software Often the functions of the data-acquisition and processing system overlap with those of the

controller to some extent As an example consider the digital-controller of vibration testing apparatus

First the responses are measured through sensors (and transducers) filtered and amplified

(conditioned) These data channels may be passed through a multiplexer whose purpose is to select

one data channel at a time for processing Most modern data acquisition hardware does not need a

separate multiplexer to handle multiple signals The analog data are converted into digital data using

analog-to-digital converters (ADCs) The resulting sampled data are stored on a disk or as a block data in

the computer memory The reference input signal (typically a signal recorded on an FM tape) is also

sampled (if it is not already in the digital form) using an ADC and fed into the computer Digital

processing is done on the reference signal and the response data with the objective of computing the

command signal to drive the shaker The digital command signal is converted into an analog signal using

a digital-to-analog converter (DAC) and amplified (conditioned) before it is used to drive the exciter

The nature of the control components depends to a large extent on the nature and objectives of the

particular test to be conducted Some of the basic components in a shaker controller are described in

the following subsections

131 Components of a Shaker Controller

1311 Compressor

A compressor circuit is incorporated in automatic excitation control devices to control the excitation-

input level automatically The level of control depends on the feedback signal from a control sensor and

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the specified (reference) excitation signal Usually the compressor circuit is included in the excitation-

signal generator (for example in a sine generator) The control by this means may be done on the basis of

a single-frequency component (eg the fundamental frequency)

1312 Equalizer (Spectrum Shaper)

Random-signal equalizers are used to shape the spectrum of a random signal in a desired manner In

essence and equalizer consists of a bank of narrow-band filters (for example 80 filters) in parallel over

the operating frequency range By passing the signal through each filter the spectral density (or the mean

square value) of the signal in that narrow frequency band (for example each one-third-octave band) is

determined This is compared with the desired spectral level and automatic adjustment is made in that

filter in case there is an error In some systems response-spectrum analysis is made in place of power

spectral density analysis In that case the equalizer consists of a bank of simple oscillators whose

resonant frequencies are distributed over the operating frequency range of the equalizer The feedback

signal is passed through each oscillator and the peak value of its output is determined This value is

compared with the desired response spectrum value at that frequency If there is an error automatic gain

adjustment is made in the appropriate excitation signal components

Random-noise equalizers are used in conjunction with random signal generators They receive

feedback signals from the control sensors In some digital control systems there are algorithms (software)

that are used to iteratively converge the spectrum of the excitation signal felt by the test object into the

desired spectrum

1313 Tracking Filter

Many vibration tests are based on single-frequency excitations In such cases the control functions

should be performed on the basis of the amplitudes of the fundamental-frequency component of the

signal A tracking filter is simply a frequency-tuned band-pass filter It automatically tunes the center

frequency of its very narrow-band-pass filter to the frequency of a carrier signal Then when a noisy

signal is passed through the tuned filter the output of the filter will be the required fundamental

frequency component in the signal Tracking filters also are useful in obtaining amplitudendashfrequency

plots using an XndashY plotter In such cases the frequency value comes from the signal generator (sweep

oscillator) which produces the carrier signal to the tracking filter The tracking filter then determines the

corresponding amplitude of a signal that is fed into it Most tracking filters have dual channels so that two

signals can be handled (tracked) simultaneously

1314 Excitation Controller (Amplitude Servo-Monitor)

An excitation controller is typically an integral part of the signal generator It can be set so that automatic

sweep between two frequency limits can be performed at a selected sweep rate (linear or logarithmic)

More advanced excitation controllers have the capability of an automatic switch-over between constant-

displacement constant-velocity and constant-acceleration excitation-input control at specified

frequencies over the sweep frequency interval Consequently integrator circuits should be present

within the excitation controller unit to determine velocities and displacements from acceleration signals

Sometimes integration is performed by a separate unit called a vibration meter This unit also offers

the operator the capability of selecting the desired level of each signal (acceleration velocity or

displacement) There is an automatic cut-off level for large displacement values that could result from

noise in acceleration signals A compressor is also a subcomponent of the excitation controller The

complete unit is sometimes known as an amplitude servo-monitor

132 Signal-Generating Equipment

Shakers are force-generating devices that are operated using drive (excitation) signals generated from a

source The excitation-signal source is known as the signal generator Three major types of signal

generators are used in vibration testing applications (1) oscillators (2) random-signal generators and

(3) storage devices In some units oscillators and random-signal generators are combined We shall

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copy 2007 by Taylor amp Francis Group LLC

discuss these two generators separately however because of their difference in function It also should be

noted that almost any digital signal (deterministic or random) can be generated by a digital computer

using a suitable computer program the signal eventually can be passed through a DAC to obtain

the corresponding analog signal These lsquodigitalrsquo signal generators along with analog sources such as

magnetic tape players (FM) are classified into the category of storage devices

The dynamic range of equipment is the ratio of the maximum and minimum output levels (expressed

in decibels) at which it is capable of operating without significant error This is an important specification

for many types of equipment particularly for signal-generating devices The output level of the signal

generator should be set to a value within its dynamic range

1321 Oscillators

Oscillators are essentially single-frequency generators Typically sine signals are generated but other

waveforms (such as rectangular and triangular pulses) are also available in most oscillators Normally

an oscillator has two modes of operation (1) sweeping up and down between two frequency limits and

(2) dwelling at a specified frequency In the sweep operation the sweep rate should be specified This can

be done either on a linear scale (Hzmin) or on a logarithmic scale (octavesmin) In the dwell operation

the frequency points (or intervals) should be specified In either case a desired signal level can be chosen

using the gain-control knob An oscillator that is operated exclusively in the sweep mode is called a sweep

oscillator

The early generation of oscillators employed variable inductor-capacitor types of electronic circuits to

generate signals oscillating at a desired frequency The oscillator is tuned to the required frequency by

varying the capacitance or inductance parameters A DC voltage is applied to energize the capacitor

and to obtain the desired oscillating voltage signal which subsequently is amplified and conditioned

Modern oscillators use operational amplifier circuits along with resistor capacitor and semiconductor

(SC) elements Also common are crystal (quartz) parallel-resonance oscillators used to generate voltage

signals accurately at a fixed frequency The circuit is activated using a DC-voltage source Other

frequencies of interest are obtained by passing this high-frequency signal through a frequency converter

The signal is then conditioned (amplified and filtered) Required shaping (for example rectangular

pulse) is obtained using a shape circuit Finally the required signal level is obtained by passing the

resulting signal through a variable-gain amplifier A block diagram of an oscillator illustrating various

stages in the generation of a periodic signal is given in Figure 113

A typical oscillator offers a choice of several (typically six) linear and logarithmic frequency ranges and

a sizable level of control capability (for example 80 dB) Upper and lower frequency limits in a sweep can

be preset on the front panel to any of the available frequency ranges Sweep-rate settings are continuously

DC Voltage

Oscillator

FrequencySpecification

FrequencyConverter

FilterAmplifier

ShaperPeriodicSignal

FrequencyCounter

Fixed-FrequencySignal

Variable-GainOutput

Amplifier

SignalSpecification

LevelSpecification

FIGURE 113 Block diagram of an oscillator-type signal generator

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  • 53191fm
    • Vibration Monitoring Testing and Instrumentation
      • Preface
      • Acknowledgments
      • Editor-in-Chief
      • Contributors
      • Contents
      • Related Titles
          • 53191ch1
            • Table of Contents
            • Chapter 1 Vibration Instrumentation
              • Summary
              • 11 Introduction
              • 12 Vibration Exciters
                • 121 Shaker Selection
                  • 1211 Force Rating
                  • 1212 Power Rating
                  • 1213 Stroke Rating
                  • 1214 Hydraulic Shakers
                  • 1215 Inertial Shakers
                  • 1216 Electromagnetic Shakers
                    • 122 Dynamics of Electromagnetic Shakers
                      • 1221 Transient Exciters
                          • 13 Control System
                            • 131 Components of a Shaker Controller
                              • 1311 Compressor
                              • 1312 Equalizer (Spectrum Shaper)
                              • 1313 Tracking Filter
                              • 1314 Excitation Controller (Amplitude Servo-Monitor)
                                • 132 Signal-Generating Equipment
                                  • 1321 Oscillators
                                  • 1322 Random Signal Generators
                                  • 1323 Tape Players
                                  • 1324 Data Processing
                                      • 14 Performance Specification
                                        • 141 Parameters for Performance Specification
                                          • 1411 Time-Domain Specifications
                                          • 1412 Frequency-Domain Specifications
                                            • 142 Linearity
                                            • 143 Instrument Ratings
                                              • 1431 Rating Parameters
                                                • 144 Accuracy and Precision
                                                  • 15 Motion Sensors and Transducers
                                                    • 151 Potentiometer
                                                      • 1511 Potentiometer Resolution
                                                      • 1512 Optical Potentiometer
                                                        • 152 Variable-Inductance Transducers
                                                          • 1521 Mutual-Induction Transducers
                                                          • 1522 Linear-Variable Differential Transformer
                                                          • 1523 Signal Conditioning
                                                            • 153 Mutual-Induction Proximity Sensor
                                                            • 154 Selfinduction Transducers
                                                            • 155 Permanent-Magnet Transducers
                                                            • 156 Alternating Current Permanent-Magnet Tachometer
                                                            • 157 Alternating Current Induction Tachometer
                                                            • 158 Eddy Current Transducers
                                                            • 159 Variable-Capacitance Transducers
                                                              • 1591 Capacitive Displacement Sensors
                                                              • 1592 Capacitive Angular Velocity Sensor
                                                              • 1593 Capacitance Bridge Circuit
                                                                • 1510 Piezoelectric Transducers
                                                                  • 15101 Sensitivity
                                                                  • 15102 Piezoelectric Accelerometer
                                                                  • 15103 Charge Amplifier
                                                                      • 16 Torque Force and Other Sensors
                                                                        • 161 Strain Gage Sensors
                                                                          • 1611 Equations for Strain Gage Measurements
                                                                          • 1612 Bridge Sensitivity
                                                                          • 1613 The Bridge Constant
                                                                          • 1614 The Calibration Constant
                                                                          • 1615 Data Acquisition
                                                                          • 1616 Accuracy Considerations
                                                                          • 1617 Semiconductor Strain Gages
                                                                          • 1618 Force and Torque Sensors
                                                                          • 1619 Strain Gage Torque Sensors
                                                                          • 16110 Deflection Torque Sensors
                                                                          • 16111 Variable-Reluctance Torque Sensor
                                                                          • 16112 Reaction Torque Sensors
                                                                            • 162 Miscellaneous Sensors
                                                                              • 1621 Stroboscope
                                                                              • 1622 Fiber Optic Sensors and Lasers
                                                                              • 1623 Fiber-Optic Gyroscope
                                                                              • 1624 Laser Doppler Interferometer
                                                                              • 1625 Ultrasonic Sensors
                                                                              • 1626 Gyroscopic Sensors
                                                                                  • References
                                                                                  • Appendix 1A Virtual Instrumentation for Data Acquisition Analysis and Presentation
                                                                                    • Summary
                                                                                    • List of Abbreviations
                                                                                    • 1A1 Dynamic Signals
                                                                                      • 1A11 Acquiring and Simulating Dynamic Signals
                                                                                        • 1A111 Aliasing
                                                                                        • 1A112 Time Continuity
                                                                                            • 1A2 Measurement Configuration Considerations
                                                                                              • 1A21 Input Signal Considerations
                                                                                                • 1A211 Input Pseudodifferential and Differential Configuration
                                                                                                • 1A212 Gain
                                                                                                • 1A213 Input Coupling
                                                                                                • 1A214 Integrated Electronic Piezoelectric Excitation
                                                                                                • 1A215 Nyquist Frequency and Bandwidth
                                                                                                • 1A216 Analog-to-Digital Conversion
                                                                                                • 1A217 Antialias Filters
                                                                                                • 1A218 Input Filter Delay
                                                                                                • 1A219 Overload Detection
                                                                                                  • 1A22 Output Signal Considerations
                                                                                                    • 1A221 Output Pseudodifferential and Differential Configuration
                                                                                                    • 1A222 Attenuation
                                                                                                    • 1A223 Digital-to-Analog Conversion
                                                                                                    • 1A224 Anti-imaging and Interpolation Filters
                                                                                                    • 1A225 Output Filter Delay
                                                                                                        • 1A3 Scaling and Calibration
                                                                                                          • 1A31 Scaling to Engineering Units
                                                                                                          • 1A32 Performing System Calibration
                                                                                                            • 1A321 Propagation Delay Calibration
                                                                                                                • 1A4 Limit Testing Analysis
                                                                                                                  • 1A41 Limit Testing Overview
                                                                                                                  • 1A42 Using the SVT Limit Testing VI
                                                                                                                    • 1A5 Integration
                                                                                                                      • 1A51 Introduction to Integration
                                                                                                                      • 1A52 Implementing Integration
                                                                                                                        • 1A521 Challenges when Integrating Vibration Data
                                                                                                                          • 1A53 Time-Domain Integration
                                                                                                                            • 1A531 Single-Shot Acquisition and Integration
                                                                                                                            • 1A532 Continuous Acquisition and Integration
                                                                                                                              • 1A54 Frequency-Domain Integration
                                                                                                                                • 1A6 Vibration-Level Measurements
                                                                                                                                  • 1A61 Measuring the Root Mean Square Level
                                                                                                                                    • 1A611 Single-Shot Buffered Acquisition
                                                                                                                                    • 1A612 Continuous Signal Acquisition
                                                                                                                                      • 1A62 Performing a Running RMS Level Measurement
                                                                                                                                      • 1A63 Computing the Peak Level
                                                                                                                                      • 1A64 Computing the Crest Factor
                                                                                                                                        • 1A7 Frequency Analysis
                                                                                                                                          • 1A71 FFT Fundamentals
                                                                                                                                            • 1A711 Number of Samples
                                                                                                                                            • 1A712 Frequency Resolution
                                                                                                                                            • 1A713 Maximum Resolvable Frequency
                                                                                                                                            • 1A714 Minimum Resolvable Frequency
                                                                                                                                            • 1A715 Number of Spectral Lines
                                                                                                                                            • 1A716 Relationship between Time-Domain and Frequency-Domain Specifications and Parameters
                                                                                                                                              • 1A72 Increasing Frequency Resolution
                                                                                                                                                • 1A721 Zoom FFT Analysis
                                                                                                                                                • 1A722 Frequency Resolution of the Zoom FFT VIs
                                                                                                                                                • 1A723 Zoom Measurement
                                                                                                                                                • 1A724 Zoom Settings
                                                                                                                                                • 1A725 Subset Analysis
                                                                                                                                                    • 1A8 Transient Analysis
                                                                                                                                                      • 1A81 Transient Analysis with the Sound and Vibration Toolkit
                                                                                                                                                      • 1A82 Performing an STFT vs Time
                                                                                                                                                        • 1A821 Selecting the FFT Block Size
                                                                                                                                                        • 1A822 Overlapping
                                                                                                                                                        • 1A823 Using the SVT STFT vs Time VI
                                                                                                                                                          • 1A83 Performing an STFT vs Rotational Speed
                                                                                                                                                            • 1A831 Converting the Pulse Train to Rotational Speed
                                                                                                                                                            • 1A832 STFT vs RPM
                                                                                                                                                              • 1A84 Measuring a Shock Response Spectrum
                                                                                                                                                                • 1A9 Waterfall Display
                                                                                                                                                                  • 1A91 Using the Display VIs
                                                                                                                                                                    • 1A911 Initializing the Display
                                                                                                                                                                    • 1A912 Sending Data to the Display
                                                                                                                                                                    • 1A913 Waterfall Display for Frequency Analysis
                                                                                                                                                                    • 1A914 Waterfall Display for Transient Analysis
                                                                                                                                                                    • 1A915 Waterfall Display for Octave Spectra
                                                                                                                                                                        • 1A10 Swept-Sine Measurements
                                                                                                                                                                          • 1A101 Swept-Sine Overview
                                                                                                                                                                          • 1A102 Choosing Swept-Sine vs FFT Measurements
                                                                                                                                                                          • 1A103 Taking a Swept-Sine Measurement
                                                                                                                                                                          • 1A104 Swept-Sine Measurement Example
                                                                                                                                                                              • Bibliography
                                                                                                                                                                              • Related Titles
                                                                                                                                                                                  • 53191ch2
                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                    • Chapter 2 Signal Conditioning and Modification
                                                                                                                                                                                      • Summary
                                                                                                                                                                                      • 21 Introduction
                                                                                                                                                                                      • 22 Amplifiers
                                                                                                                                                                                        • 221 Operational Amplifier
                                                                                                                                                                                        • 222 Use of Feedback in Opamp
                                                                                                                                                                                        • 223 Voltage Current and Power Amplifiers
                                                                                                                                                                                          • 2231 Charge Amplifiers
                                                                                                                                                                                            • 224 Instrumentation Amplifiers
                                                                                                                                                                                              • 2241 Differential Amplifier
                                                                                                                                                                                              • 2242 Common Mode
                                                                                                                                                                                                • 225 Amplifier Performance Ratings
                                                                                                                                                                                                  • 2251 Common-Mode Rejection Ratio
                                                                                                                                                                                                    • 226 Component Interconnection
                                                                                                                                                                                                      • 2261 Impedance Characteristics
                                                                                                                                                                                                      • 2262 Cascade Connection of Devices
                                                                                                                                                                                                      • 2263 AC-Coupled Ampliers
                                                                                                                                                                                                          • 23 Analog Filters
                                                                                                                                                                                                            • 231 Passive Filters and Active Filters
                                                                                                                                                                                                              • 2311 Number of Poles
                                                                                                                                                                                                                • 232 Low-Pass Filters
                                                                                                                                                                                                                  • 2321 Low-Pass Butterworth Filter
                                                                                                                                                                                                                    • 233 High-Pass Filters
                                                                                                                                                                                                                    • 234 Band-Pass Filters
                                                                                                                                                                                                                      • 2341 Resonance-Type Band-Pass Filters
                                                                                                                                                                                                                        • 235 Band-Reject Filters
                                                                                                                                                                                                                          • 24 Modulators and Demodulators
                                                                                                                                                                                                                            • 241 Amplitude Modulation
                                                                                                                                                                                                                              • 2411 Modulation Theorem
                                                                                                                                                                                                                              • 2412 Side Frequencies and Side Bands
                                                                                                                                                                                                                                • 242 Application of Amplitude Modulation
                                                                                                                                                                                                                                  • 2421 Fault Detection and Diagnosis
                                                                                                                                                                                                                                    • 243 Demodulation
                                                                                                                                                                                                                                      • 25 Analog ndashDigital Conversion
                                                                                                                                                                                                                                        • 251 Digital-to-Analog Conversion
                                                                                                                                                                                                                                          • 2511 DAC Error Sources
                                                                                                                                                                                                                                            • 252 Analog-to-Digital Conversion
                                                                                                                                                                                                                                            • 253 Analog-to-Digital Converter Performance Characteristics
                                                                                                                                                                                                                                              • 2531 Resolution and Quantization Error
                                                                                                                                                                                                                                              • 2532 Monotonicity Nonlinearity and Offset Error
                                                                                                                                                                                                                                              • 2533 Analog-to-Digital Converter Conversion Rate
                                                                                                                                                                                                                                                • 254 Sample-and-Hold Circuitry
                                                                                                                                                                                                                                                • 255 Digital Filters
                                                                                                                                                                                                                                                  • 2551 Software Implementation and Hardware Implementation
                                                                                                                                                                                                                                                      • 26 Bridge Circuits
                                                                                                                                                                                                                                                        • 261 Wheatstone Bridge
                                                                                                                                                                                                                                                        • 262 Constant-Current Bridge
                                                                                                                                                                                                                                                        • 263 Bridge Amplifiers
                                                                                                                                                                                                                                                          • 2631 Half-Bridge Circuits
                                                                                                                                                                                                                                                            • 264 Impedance Bridges
                                                                                                                                                                                                                                                              • 2641 Owen Bridge
                                                                                                                                                                                                                                                              • 2642 Wien-Bridge Oscillator
                                                                                                                                                                                                                                                                  • 27 Linearizing Devices
                                                                                                                                                                                                                                                                    • 271 Linearization by Software
                                                                                                                                                                                                                                                                    • 272 Linearization by Hardware Logic
                                                                                                                                                                                                                                                                    • 273 Analog Linearizing Circuitry
                                                                                                                                                                                                                                                                    • 274 Offsetting Circuitry
                                                                                                                                                                                                                                                                    • 275 Proportional-Output Circuitry
                                                                                                                                                                                                                                                                      • 2751 Curve-Shaping Circuitry
                                                                                                                                                                                                                                                                          • 28 Miscellaneous Signal Modification Circuitry
                                                                                                                                                                                                                                                                            • 281 Phase Shifters
                                                                                                                                                                                                                                                                            • 282 Voltage-to-Frequency Converter
                                                                                                                                                                                                                                                                            • 283 Frequency-to-Voltage Converter
                                                                                                                                                                                                                                                                            • 284 Voltage-to-Current Converters
                                                                                                                                                                                                                                                                            • 285 Peak-Hold Circuits
                                                                                                                                                                                                                                                                              • 29 Signal Analyzers and Display Devices
                                                                                                                                                                                                                                                                                • 291 Signal Analyzers
                                                                                                                                                                                                                                                                                • 292 Oscilloscopes
                                                                                                                                                                                                                                                                                  • 2921 Triggering
                                                                                                                                                                                                                                                                                  • 2922 Lissajous Patterns
                                                                                                                                                                                                                                                                                  • 2923 Digital Oscilloscopes
                                                                                                                                                                                                                                                                                      • Bibliography
                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                          • 53191ch3
                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                            • Chapter 3 Vibration Testing
                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                              • 31 Introduction
                                                                                                                                                                                                                                                                                              • 32 Representation of a Vibration Environment
                                                                                                                                                                                                                                                                                                • 321 Test Signals
                                                                                                                                                                                                                                                                                                  • 3211 Stochastic vs Deterministic Signals
                                                                                                                                                                                                                                                                                                    • 322 Deterministic Signal Representation
                                                                                                                                                                                                                                                                                                      • 3221 Single-Frequency Signals
                                                                                                                                                                                                                                                                                                      • 3222 Sine Sweep
                                                                                                                                                                                                                                                                                                      • 3223 Sine Dwell
                                                                                                                                                                                                                                                                                                      • 3224 Decaying Sine
                                                                                                                                                                                                                                                                                                      • 3225 Sine Beat
                                                                                                                                                                                                                                                                                                      • 3226 Sine Beat with Pauses
                                                                                                                                                                                                                                                                                                      • 3227 Multifrequency Signals
                                                                                                                                                                                                                                                                                                      • 3228 Actual Excitation Records
                                                                                                                                                                                                                                                                                                      • 3229 Simulated Excitation Signals
                                                                                                                                                                                                                                                                                                        • 323 Stochastic Signal Representation
                                                                                                                                                                                                                                                                                                          • 3231 Ergodic Random Signals
                                                                                                                                                                                                                                                                                                          • 3232 Stationary Random Signals
                                                                                                                                                                                                                                                                                                          • 3233 Independent and Uncorrelated Signals
                                                                                                                                                                                                                                                                                                          • 3234 Transmission of Random Excitations
                                                                                                                                                                                                                                                                                                            • 324 Frequency-Domain Representations
                                                                                                                                                                                                                                                                                                              • 3241 Fourier Spectrum Method
                                                                                                                                                                                                                                                                                                              • 3242 Power Spectral Density Method
                                                                                                                                                                                                                                                                                                                • 325 Response Spectrum
                                                                                                                                                                                                                                                                                                                  • 3251 Displacement Velocity and Acceleration Spectra
                                                                                                                                                                                                                                                                                                                  • 3252 Response-Spectra Plotting Paper
                                                                                                                                                                                                                                                                                                                  • 3253 Zero-Period Acceleration
                                                                                                                                                                                                                                                                                                                  • 3254 Uses of Response Spectra
                                                                                                                                                                                                                                                                                                                    • 326 Comparison of Various Representations
                                                                                                                                                                                                                                                                                                                      • 33 Pretest Procedures
                                                                                                                                                                                                                                                                                                                        • 331 Purpose of Testing
                                                                                                                                                                                                                                                                                                                        • 332 Service Functions
                                                                                                                                                                                                                                                                                                                          • 3321 Active Equipment
                                                                                                                                                                                                                                                                                                                          • 3322 Passive Equipment
                                                                                                                                                                                                                                                                                                                          • 3323 Functional Testing
                                                                                                                                                                                                                                                                                                                            • 333 Information Acquisition
                                                                                                                                                                                                                                                                                                                              • 3331 Interface Details
                                                                                                                                                                                                                                                                                                                              • 3332 Effect of Neglecting Interface Dynamics
                                                                                                                                                                                                                                                                                                                              • 3333 Effects of Damping
                                                                                                                                                                                                                                                                                                                              • 3334 Effects of Inertia
                                                                                                                                                                                                                                                                                                                              • 3335 Effect of Natural Frequency
                                                                                                                                                                                                                                                                                                                              • 3336 Effect of Excitation Frequency
                                                                                                                                                                                                                                                                                                                              • 3337 Other Effects of Interface
                                                                                                                                                                                                                                                                                                                                • 334 Test-Program Planning
                                                                                                                                                                                                                                                                                                                                  • 3341 Testing of Cabinet-Mounted Equipment
                                                                                                                                                                                                                                                                                                                                    • 335 Pretest Inspection
                                                                                                                                                                                                                                                                                                                                      • 34 Testing Procedures
                                                                                                                                                                                                                                                                                                                                        • 341 Resonance Search
                                                                                                                                                                                                                                                                                                                                        • 342 Methods of Determining Frequency-Response Functions
                                                                                                                                                                                                                                                                                                                                          • 3421 Fourier Transform Method
                                                                                                                                                                                                                                                                                                                                          • 3422 Spectral Density Method
                                                                                                                                                                                                                                                                                                                                          • 3423 Harmonic Excitation Method
                                                                                                                                                                                                                                                                                                                                            • 343 Resonance-Search Test Methods
                                                                                                                                                                                                                                                                                                                                              • 3431 Hammer (Bump) Test and Drop Test
                                                                                                                                                                                                                                                                                                                                              • 3432 Pluck Test
                                                                                                                                                                                                                                                                                                                                              • 3433 Shaker Tests
                                                                                                                                                                                                                                                                                                                                                • 344 Mechanical Aging
                                                                                                                                                                                                                                                                                                                                                  • 3441 Equivalence for Mechanical Aging
                                                                                                                                                                                                                                                                                                                                                  • 3442 Excitation-Intensity Equivalence
                                                                                                                                                                                                                                                                                                                                                  • 3443 Dynamic-Excitation Equivalence
                                                                                                                                                                                                                                                                                                                                                  • 3444 Cumulative Damage Theory
                                                                                                                                                                                                                                                                                                                                                    • 345 Test-Response Spectrum Generation
                                                                                                                                                                                                                                                                                                                                                    • 346 Instrument Calibration
                                                                                                                                                                                                                                                                                                                                                    • 347 Test-Object Mounting
                                                                                                                                                                                                                                                                                                                                                    • 348 Test-Input Considerations
                                                                                                                                                                                                                                                                                                                                                      • 3481 Test Nomenclature
                                                                                                                                                                                                                                                                                                                                                      • 3482 Testing with Uncorrelated Excitations
                                                                                                                                                                                                                                                                                                                                                      • 3483 Symmetrical Rectilinear Testing
                                                                                                                                                                                                                                                                                                                                                      • 3484 Geometry vs Dynamics
                                                                                                                                                                                                                                                                                                                                                      • 3485 Some Limitations
                                                                                                                                                                                                                                                                                                                                                      • 3486 Testing Black Boxes
                                                                                                                                                                                                                                                                                                                                                      • 3487 Phasing of Excitations
                                                                                                                                                                                                                                                                                                                                                      • 3488 Testing a Gray or White Box
                                                                                                                                                                                                                                                                                                                                                      • 3489 Overtesting in Multitest Sequences
                                                                                                                                                                                                                                                                                                                                                          • 35 Some Practical Information
                                                                                                                                                                                                                                                                                                                                                            • 351 Random Vibration Test Example
                                                                                                                                                                                                                                                                                                                                                            • 352 Vibration Shakers and Control Systems
                                                                                                                                                                                                                                                                                                                                                              • Bibliography
                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                  • 53191ch4
                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                    • Chapter 4 Experimental Modal Analysis
                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                      • 41 Introduction
                                                                                                                                                                                                                                                                                                                                                                      • 42 Frequency-Domain Formulation
                                                                                                                                                                                                                                                                                                                                                                        • 421 Transfer-Function Matrix
                                                                                                                                                                                                                                                                                                                                                                        • 422 Principle of Reciprocity
                                                                                                                                                                                                                                                                                                                                                                          • 43 Experimental Model Development
                                                                                                                                                                                                                                                                                                                                                                            • 431 Extraction of the Time-Domain Model
                                                                                                                                                                                                                                                                                                                                                                              • 44 Curve Fitting of Transfer Functions
                                                                                                                                                                                                                                                                                                                                                                                • 441 Problem Identification
                                                                                                                                                                                                                                                                                                                                                                                • 442 Single- and Multi-Degree-of-Freedom Techniques
                                                                                                                                                                                                                                                                                                                                                                                • 443 Single-Degree-of-Freedom Parameter Extraction in the Frequency Domain
                                                                                                                                                                                                                                                                                                                                                                                  • 4431 Circle-Fit Method
                                                                                                                                                                                                                                                                                                                                                                                    • Case of Viscous Damping
                                                                                                                                                                                                                                                                                                                                                                                    • Case of Hysteretic Damping
                                                                                                                                                                                                                                                                                                                                                                                      • 4432 Peak-Picking Method
                                                                                                                                                                                                                                                                                                                                                                                        • 444 Multi-Degree of Freedom Curve Fitting
                                                                                                                                                                                                                                                                                                                                                                                          • 4441 Formulation of the Method
                                                                                                                                                                                                                                                                                                                                                                                            • 445 A Comment on Static Modes and Rigid-Body Modes
                                                                                                                                                                                                                                                                                                                                                                                            • 446 Residue Extraction
                                                                                                                                                                                                                                                                                                                                                                                              • 45 Laboratory Experiments
                                                                                                                                                                                                                                                                                                                                                                                                • 451 Lumped-Parameter System
                                                                                                                                                                                                                                                                                                                                                                                                  • 4511 Frequency-Domain Test
                                                                                                                                                                                                                                                                                                                                                                                                  • 4512 Time-Domain Tests
                                                                                                                                                                                                                                                                                                                                                                                                    • 452 Distributed-Parameter System
                                                                                                                                                                                                                                                                                                                                                                                                      • 46 Commercial EMA Systems
                                                                                                                                                                                                                                                                                                                                                                                                        • 461 System Configuration
                                                                                                                                                                                                                                                                                                                                                                                                          • 4611 FFT Analysis Options
                                                                                                                                                                                                                                                                                                                                                                                                          • 4612 Modal Analysis Components
                                                                                                                                                                                                                                                                                                                                                                                                              • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                  • 53191ch5
                                                                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                    • Chapter 5 Mechanical Shock
                                                                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                      • 51 Definitions
                                                                                                                                                                                                                                                                                                                                                                                                                        • 511 Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 512 Simple (or Perfect) Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 513 Half-Sine Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 514 Versed-Sine (or Haversine) Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 515 Terminal Peak Sawtooth Shock or Final Peak Sawtooth Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 516 Rectangular Shock
                                                                                                                                                                                                                                                                                                                                                                                                                          • 5161 Trapezoidal Shock
                                                                                                                                                                                                                                                                                                                                                                                                                              • 52 Description in the Time Domain
                                                                                                                                                                                                                                                                                                                                                                                                                              • 53 Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                • 531 Need
                                                                                                                                                                                                                                                                                                                                                                                                                                • 532 Shock Response Spectrum Definition
                                                                                                                                                                                                                                                                                                                                                                                                                                • 533 Response of a Linear One-Degree-of-Freedom System
                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5331 Shock Defined by a Force
                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5332 Shock Defined by an Acceleration
                                                                                                                                                                                                                                                                                                                                                                                                                                    • 534 Definitions
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5341 Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5342 Absolute Acceleration Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5343 Relative Displacement Shock Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5344 Primary Positive Shock Response Spectrum or Initial Positive Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5345 Primary (or Initial) Negative Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5346 Secondary (or Residual) Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5347 Positive (or Maximum Positive) Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5348 Negative (or Maximum Negative) Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5349 Maximax Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53410 Choice of Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                        • 535 Standardized Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5351 Definition
                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5352 Standardized Shock Response Spectra of Simple Shocks
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53521 Half-Sine Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53522 Versed Sine Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53523 Terminal Peak Sawtooth Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53524 Rectangular Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53525 Trapezoidal Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 536 Choice of Damping
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 537 Shock Response Spectra Domains
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 538 Algorithms for Calculation of the Shock Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 539 Choice of the Digitization Frequency of the Signal
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5310 Use of Shock Response Spectra for the Study of Systems with Several Degrees of Freedom
                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 54 Pyroshocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 55 Use of Shock Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 551 Severity Comparison of Several Shocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 552 Test Specification Development from Real Environment Data
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5521 Synthesis of Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5522 Nature of the Specification
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5523 Choice of Shape
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5524 Amplitude
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5525 Duration
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5526 Difficulties
                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 56 Standards
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 561 Types of Standards
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 562 Installation Conditions of Test Item
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 563 Uncertainty Factor
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 564 Bump Test
                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 57 Damage Boundary Curve
                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 571 Definition
                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 572 Analysis of Test Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 58 Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 581 Main Types
                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 582 Impact Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5821 Universal Shock-Test Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 58211 Impact Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 58212 Impulse Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 583 Shock Simulators (Programmers)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5831 Half-Sine Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58311 Shock Duration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58312 Impact Velocity
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58313 Maximum Deformation of the Shock Simulator (Programmer)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58314 Shock Amplitude
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58315 Characteristics of the Target
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5832 Terminal Peak Sawtooth Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5833 Rectangular Pulse ndash Trapezoidal Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5834 Universal Shock Simulator (Programmer)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 58341 Generating a Half-Sine Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 58342 Generating a Terminal Peak Sawtooth Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 58343 Trapezoidal Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 584 Limitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5841 Limitations of the Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5842 Limitations of Shock Simulators
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 585 Pneumatic Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 586 High Impact Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5861 Lightweight High Impact Shock Machine
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5862 Medium Weight High Impact Shock Machine
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 587 Specific Test Facilities
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 59 Generation of Shock Using Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 591 Principle Behind the Generation of a Simple Shape Signal versus Time
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 592 Main Advantages
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 593 Pre- and Postshocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5931 Requirements
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5932 Solutions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 59321 Optimized Pre- and Postpulses
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5933 Incidence on the Shock Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 594 Limitations of Electrodynamic Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5941 Mechanical Limitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 59411 Abacuses
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5942 Electronic Limitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 595 The Use of Electrohydraulic Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 510 Control by a Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 5101 Principle
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 5102 Principal Shapes of Elementary Signals
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 51021 Decaying Sinusoid
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 51022 ZERD Function
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 51023 WAVSIN Waveform
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 5103 Comparison of WAVSIN SHOC Waveforms and Decaying Sinusoid
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 5104 Criticism of Control by a Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 511 Pyrotechnic Shock Simulation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5111 Simulation Using Pyrotechnic Facilities
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5112 Simulation Using Metal-to-Metal Impact
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5113 Simulation Using Electrodynamic Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5114 Simulation Using Conventional Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53191ch6
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Chapter 6 Machine Condition Monitoring and Fault Diagnostics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 61 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 62 Machinery Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 621 Causes of Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 622 Types of Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 623 Frequency of Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 63 Basic Maintenance Strategies
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 631 Run-to-Failure (Breakdown) Maintenance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 632 Scheduled (Preventative) Maintenance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 633 Condition-Based (Predictive Proactive Reliability Centered On-Condition) Maintenance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 64 Factors Which Influence Maintenance Strategy
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 65 Machine Condition Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 651 Periodic Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 652 Continuous Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 66 Transducer Selection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 661 Noncontact Displacement Transducers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 662 Velocity Transducers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 663 Acceleration Transducers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 67 Transducer Location
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 68 Recording and Analysis Instrumentation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 681 Vibration Meters
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 682 Data Collectors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 683 Frequency-Domain Analyzers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 684 Time-Domain Instruments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 685 Tracking Analyzers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 69 Display Formats and Analysis Tools
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 691 Time Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6911 Time-Waveform Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6912 Time-Waveform Indices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6913 Time-Synchronous Averaging
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6914 Negative Averaging
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6915 Orbits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6916 Probability Density Functions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6917 Probability Density Moments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 692 Frequency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6921 Band-Pass Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6922 Shock Pulse (Spike Energy)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6923 Enveloped Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6924 Signature Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6925 Cascades (Waterfall Plots)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6926 Masks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6927 Frequency-Domain Indices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 693 Modal Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 694 Quefrency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 610 Fault Detection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 6101 Standards
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61011 Standards Based on Machinery Type
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61012 Standards Based on Vibration Severity
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 6102 Acceptance Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 61021 Statistical Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 6103 Frequency-Domain Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61031 Limited Band Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61032 Constant Bandwidth Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61033 Constant Percentage Bandwidth Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 611 Fault Diagnostics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 6111 Forcing Functions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61111 Unbalance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61112 Misalignment
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61113 Mechanical Looseness
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61114 Soft Foot
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61115 Rubs
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61116 Resonances
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61117 Oil Whirl
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61118 Oil Whip
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61119 Structural Vibrations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 611110 Foundation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 6112 Specific Machine Components
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 61121 Damaged or Worn Rolling-Element Bearings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 61122 Damaged or Worn Gears
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 6113 Specific Machine Types
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61131 Pumps
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61132 Fans
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61133 Electric Motors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61134 Steam and Gas Turbines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61135 Compressors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61136 Reciprocating Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 6114 Advanced Fault Diagnostic Techniques
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 53191ch7
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • Chapter 7 Vibration-Based Tool Condition Monitoring Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 71 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 72 Mechanics of Turning
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 721 General Terms
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 722 Chatter Vibrations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 723 Tool Wear
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7231 Tool Failure Mechanisms
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7232 Tool Failure Modes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7233 Tool Wear Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7234 Tool Wear Stages
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 73 Vibration Signal Recording
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 731 Direct and Indirect Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 732 Sensor Requirements for Tool Wear Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 733 Force Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7331 Direct Measurement Dynamometers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7332 Indirect Force Sensors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7333 Piezoelectric Strain Sensors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7334 Resistance Strain Gauges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7335 Customized Force Sensors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 734 Acceleration Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 735 Acoustic Emission Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 736 Sensor Comparisons
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 74 Signal Processing for Sensor-Based Tool Condition Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 741 Feature Extraction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7411 Time Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7412 Frequency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7413 Statistical Processing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7414 TimendashFrequency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 742 Feature Selection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 75 Wear ModelDecision-Making for Sensor-Based Tool Condition Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 751 Trending Threshold
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 752 Neural Networks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7521 Unsupervised Networks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7522 Supervised Networks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 753 Fuzzy Logic
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 754 Other Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 76 Conclusion
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53191ch8
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Chapter 8 Fault Diagnosis of Helicopter Gearboxes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 81 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 82 Abnormality Scaling
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 83 The Structure-Based Connectionist Network
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 84 Sensor Location Selection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 841 Coverage Index
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 842 Overlap Index
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 843 Monitoring Effectiveness
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 85 A Case Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 851 Structural and Featural Influences
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 852 Evaluation of Influences
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 853 Fault Detection Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 854 Fault Diagnostic Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 8541 Faulty Subsystem Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 8542 Faulty Component Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 855 Sensor Location Evaluation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 856 Sensor Location Validation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 86 Conclusion
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 53191ch9
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Chapter 9 Vibration Suppression and Monitoring in Precision Motion Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 91 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 92 Mechanical Design to Minimize Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 921 Stability and Static Determinacy of Machine Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 922 Two-Dimensional Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 923 Three-Dimensional Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 93 Adaptive Notch Filter
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 931 Fast Fourier Transform
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 932 Simulation and Experiments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 94 Real-Time Vibration Analyzer
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 941 Learning Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 942 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 943 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 944 Experiments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 9441 Input Variables mdash the Evaluation Criteria
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 94411 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 94412 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 9442 Evaluation Rules
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 94421 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 94422 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 9443 Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 94431 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 94432 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 95 Practical Insights and Case Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 96 Conclusions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 53191ch10
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Chapter 10 Vibration and Shock Problems of Civil Engineering Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 101 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 102 Earthquake-Induced Vibration of Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1021 Seismicity and Ground Motions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1022 Influence of Local Site Conditions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1023 Response of Structures to Ground Motions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1024 Dynamic Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10241 Equations of Motion for Linear Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10242 Equations of Motion for Linear Multiple-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1025 Earthquake Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10251 Elastic Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10252 Smoothed Design Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10253 Ductility-Modified Response Spectrum Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1026 Design Philosophy and the Code Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10261 Performance-Based Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1027 Analysis Options for Earthquake Effects
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10271 Dynamic Time History Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10272 Response Spectrum Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 102721 Response Spectrum Analysis of Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 102722 Response Spectrum Analysis of Multi-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10273 Equivalent Static Analysis (Force-Based Approach)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10274 Displacement-Based Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1028 SoilndashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1029 Active and Passive Control Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 10210 Worked Examples
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 103 Dynamic Effects of Wind Loading on Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1031 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1032 Wind Speed
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1033 Design Structures for Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10331 Types of Wind Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10332 Design Criteria
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10333 Static Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1034 Along and Across-Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10341 Along-Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10342 Across-Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1035 Wind Tunnel Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1036 Comfort Criteria Human Response to Building Motion
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1037 Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1038 Comparison with Earthquake Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 104 Vibrations Due to Fluid ndashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1041 Added Mass and Inertial Coupling
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1042 Wave-Induced Vibration of Structure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 105 Blast Loading and Blast Effects on Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1051 Explosions and Blast Phenomenon
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1052 Explosive Air-Blast Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10521 Blast Wave Scaling Laws
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10522 Prediction of Blast Pressure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1053 Gas Explosion Loading and Effect of Internal Explosions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1054 Structural Response to Blast Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10541 Elastic Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10542 Elasto-Plastic Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1055 Material Behaviors at High Strain Rate
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10551 Dynamic Properties of Concrete under High Strain Rates
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10552 Dynamic Properties of Reinforcing Steel under High Strain Rates
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1056 Failure Modes of Blast-Loaded Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10561 Global Structural Behavior
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10562 Localized Structural Behavior
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10563 PressurendashImpulse ( PndashI ) Diagrams
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1057 Blast WavendashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1058 Effect of Ground Shocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10581 Loads from Air-Induced Ground Shock
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10582 Loads from Direct Ground Shock
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1059 Technical Design Manuals for Blast-Resistant Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 10510 Computer Programs for Blast and Shock Effects
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 106 Impact Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1061 Structural Impact between Two Bodies mdash Hard Impact and Soft Impact
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1062 Example mdash Aircraft Impact
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 107 Floor Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1071 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1072 Types of Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10721 Walking
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10722 Rhythmic Activities
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10723 Mechanical Equipment
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10724 Analysis Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1073 Natural Frequency of Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10731 Computing the Natural Frequency
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10732 Computing Deflection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10733 Damping
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10734 Resonance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1074 Vibration Caused by Walking
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10741 Minimum Natural Frequency
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1075 Design for Rhythmic Excitation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10751 Harmonics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10752 Minimum Natural Frequency
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1076 Example mdash Vibration Analysis of a Reinforced Concrete Floor
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 53191ch11
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Chapter 11 Seismic Base Isolation and Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 111 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1111 From Ductility Design to Base Isolation and Control Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1112 The Importance of Reducing Seismic Input and Response
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 112 Seismic Base Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1121 Historical Development of Base Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1122 Basic Principle
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1123 Issues in Seismic Base Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11231 Performance Criteria
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11232 Type of Structure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11233 Site Characteristics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11234 Retrofit Issues
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11235 Design of Building Services
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11236 Expected Life of Isolator
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1124 Seismic Isolation Devices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11241 Laminated Rubber Bearings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11242 Lead Rubber Bearing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11243 Friction-Based Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11244 Other Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1125 Design of Isolation Devices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11251 High-Damping Rubber Bearing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112511 Stability against Buckling
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112512 Stability against Roll Out
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11252 Lead Rubber Bearings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112521 Design of Lead Plug
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112522 Design of Laminated Rubber Bearing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11253 Design of Friction Pendulum System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1126 Verification of Properties of Isolation Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11261 Tests for Isolation Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 112611 System Characterization Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 112612 Prototype Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 112613 Quality Control Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11262 Uniform Building Code Recommendations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112621 Units Dependent on Loading Rates
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112622 Units Dependent on Bilateral Load
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112623 System Adequacy
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1127 Analysis of Base-Isolated Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11271 Modeling of a Superstructure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11272 Modeling of Isolation System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11273 Static Analysis Procedure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11274 Dynamic Analysis Procedure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 112741 Response Spectrum Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 112742 Time-History Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11275 Software for Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1128 Experimental Methods for Isolated Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1129 Implementation of Seismic Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11291 New Construction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112911 Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112912 Bridges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11292 Seismic Retrofit
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112921 Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112922 Bridges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11293 Other Implementations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 11210 Performance during Past Earthquakes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 112101 Performance of Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 112102 Performance of Bridges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 113 Seismic Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1131 Historical Development of Seismic Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1132 Basic Principles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11321 Passive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11322 Active Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11323 Semiactive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11324 Hybrid Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11325 Categorization of Basic Principles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1133 Important Issues in Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11331 SoilndashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11332 DevicendashStructure Interaction and Time Delay
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11333 Design Guidelines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1134 Vibration-Control Devices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11341 Passive Control Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113411 Metallic Yielding Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113412 Friction Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113413 Viscoelastic Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113414 Viscous Fluid Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113415 Tuned Mass Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11342 Active Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113421 Electromagnetic Actuator
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113422 Hydraulic Actuators
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11343 Semiactive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113431 Variable-Orifice Hydraulic Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113432 Controllable Fluid Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113433 Controllable Friction Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11344 Hybrid Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1135 Control Algorithm
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11351 Active Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11352 Semiactive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113521 Common Control Schemes for Controllable Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113522 Special Control Schemes for Controllable Damper
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1136 Experimental Performance Verification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11361 Shaking Table Tests of a Flexible Structural Model with TMD AMD and ATMD
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11362 Substructure Hybrid Test
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113621 Hybrid Tests Using Hydraulic Actuator
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113622 Hybrid Tests Using Shaking Table
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113623 Hybrid Tests Using Inertia-Force-Driven Loading System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1137 Implementations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11371 Semiactive Control of Full-Scale Structures Using Variable Joint Damper System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113711 Background of Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113712 Test System Set Up
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113713 Control Algorithm
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113714 Test Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11372 Application of Structural Control Technologies to Seismic Retrofit of a Cable-Stayed Bridge
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113721 Background of Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113722 Basic Concept of Seismic Retrofit
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113723 Modal Shape Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113724 Time-History Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113725 Soil ndash Structure Interaction Effect
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113726 Semiactive Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53191ch12
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Chapter 12 Seismic Random Vibration of Long-Span Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 121 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1211 Basic Concepts of Random Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12111 Stationary Random Process
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12112 Nonstationary Random Process
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1212 Three Methods for Structural Seismic Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12121 Response Spectrum Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12122 Time-History Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12123 Random Vibration Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 121231 Davenport Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 121232 Vanmarcke Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 12124 Comparisons of the Three Seismic-Analysis Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 122 Seismic Random-Excitation Fields
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1221 Power Spectral Density of Spatially Varying Ground Acceleration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1222 Several Coherence Models
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12221 FengndashHu Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12222 Harichandran ndashVanmarcke Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12223 LohndashYeh Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12224 OliveirandashHaondashPenzien Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12225 LucondashWong Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12226 QundashWangndashWang Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1223 Generation of Ground Acceleration Power Spectral Density Curves from Acceleration Response Spectrum Curves
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12231 Kaul Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12232 Iteration Scheme
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1224 Seismic Equations of Motion of Long-Span Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1225 Seismic Waves and Their Geometrical Expressions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 123 Pseudoexcitation Method for Structural Random Vibration Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1231 Structures Subjected to Stationary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12311 Single Stationary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12312 Multiple Stationary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1232 Structures Subjected to Nonstationary Random Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12321 Structures Subjected to Uniformly Modulated Evolutionary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 123211 Single Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 123212 Multiple Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12322 Structures Subjected to Nonuniformly Modulated Evolutionary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 123221 Single Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 123222 Multiple Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1233 Precise Integration Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12331 Precise Integration of Exponential Matrices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12332 Particular Solutions and Precise Integration Formulas for Various Forms of Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 123321 Linear Loading Form (HPD-L Form)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 123322 Sinusoidal Loading Form (HPD-S Form)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 123323 Exponentially Decaying Sinusoidal Loading Form (HPD-E Form)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 124 Long-Span Structures Subjected to Stationary Random Ground Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1241 The Solution of Equations of Motion Using the Pseudoexcitation Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1242 Numerical Comparisons with Other Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12421 Song-Hua-Jiang Suspension Bridge
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 124211 All Supports Move Uniformly
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 124212 Wave Passage Effect Is Taken into Account
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 124213 Wave-Passage Effect and Incoherence Effect Are Jointly Taken into Account
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 12422 San Joaquin Concrete Bridge
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 125 Long-Span Structures Subjected to Nonstationary Random Ground Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1251 Modulation Functions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1252 The Formulas for Nonstationary Multiexcitation Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1253 Expected Extreme Values of Nonstationary Random Processes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1254 Numerical Comparisons with the Corresponding Stationary Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 126 Conclusions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 53191ch13
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Chapter 13 Seismic Qualification of Equipment
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 131 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 132 Distribution Qualification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1321 Drive-Signal Generation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1322 Distribution Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1323 Test Procedures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 133 Seismic Qualification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1331 Stages of Seismic Qualification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1332 Test Preliminaries
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1333 Single-Frequency Testing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1334 Multifrequency Testing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1335 Generation of RRS Specifications
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Related Titles
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                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Chapter 14 Human Response to Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 141 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 142 Vibration Excitations on Humans
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1421 Excitation Characteristics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 143 Human Response to Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1431 Vibration Perception
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1432 Frequency Weighting Curve
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1433 Iso-Perception Curves
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1434 Detection Threshold Curve
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 144 Regulation of Human Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1441 Acceptable Vibration Levels in Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1442 Whole-Body Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1443 HandndashArm Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
Page 25: Vibration Monitoring, Testing, and Instrumentationpreview.kingborn.net › 646000 › d1a74678d91943e5ba1d5e... · The MEMS Handbook, Second Edition MEMS: Introduction and Fundamentals

by the static deflections of the flexible elements and that the displacements are measured from the static

equilibrium position we have the following system equations

Test object meuroy frac14 2kethy2 yeTHORN2 beth_y2 _yeTHORN eth119THORNShaker head me euroye frac14 fe thorn kethy2 yeTHORN thorn beth_y2 _yeTHORN2 key 2 be _ye eth120THORN

Electrical Lediedt

thorn Reie thorn kb _ye frac14 vethtTHORN eth121THORN

The electromagnetic force fe generated in the shaker head is a result of the interaction of the magnetic

field generated by the current ie with coil of the moving shaker head and the constant magnetic field

(stator) in which the head coil is located Here we have

fe frac14 kbie eth122THORNNote that v(t) is the voltage signal that is applied by the amplifier to the shaker coil ye is the displacement

of the shaker head and y is the displacement response of the test package

It is assumed that kb has consistent electrical and mechanical units (Vmsec and NA) Usually

the electrical time constant of the shaker is quite small compared with the primarily mechanical

time constants of the shaker and the test package In such cases the Ledie=dt term in Equation 121 may

be neglected Consequently the equations from Equation 119 through Equation 122 may be

expressed in the Laplace (frequency) domain with the Laplace variable s taking the place of the derivative

d=dt as

ethms2 thorn bsthorn kTHORNy frac14 ethbsthorn kTHORNye eth123THORN

FIGURE 19 Dynamic models of an electromagnetic shaker and a flexible test package (a) mechanical model

(b) electrical model

Vibration Instrumentation 1-13

53191mdash522007mdash1202mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

frac12mes2 thorn ethbthorn beTHORNsthorn ethkthorn keTHORN ye frac14 ethbsthorn kTHORNy thorn kb

Rev2

k2bs

Reye eth124THORN

It follows that the transfer function of the shaker head motion with respect to the excitation voltage is

given by

yevfrac14 kb

Re

DethsTHORNDdethsTHORN eth125THORN

where DethsTHORN is the characteristic function of the primary dynamics of the test object

DethsTHORN frac14 ms2 thorn bsthorn k eth126THORN

and DdethsTHORN is the characteristic function of the primary dynamic interactions between the shaker and thetest object

DcethsTHORN frac14 mmes4 thorn frac12methbe thorn bthorn boTHORN thornmeb s

3 thorn frac12methke thorn kTHORN thornmekthorn bethbe thorn boTHORN s2thorn frac12bke thorn ethbe thorn boTHORNk sthorn kke

eth127THORN

where

bo frac14 k2bRe

eth128THORN

It is clear that under low damping conditions DdethsTHORN will produce two resonances as it is fourth order in sand similarly DethsTHORN will produce one antiresonance (trough) corresponding to the resonance of the testobject Note that in the frequency domain s frac14 jv and hence the frequency response function given by

Equation 125 is in fact

yevfrac14 kb

Rb

DethjvTHORNDdethjvTHORN eth129THORN

The magnitude of this frequency response function for a typical test system is sketched in Figure 110

Note that this curve is for the ldquoopen-looprdquo case where there is no feedback from the shaker controller

In practice the shaker controller will be able

to compensate for the resonances and anti-

resonances to some degree depending on its

effectiveness

The main advantages of electromagnetic

shakers are their high frequency range of

operation their high degree of operating flexi-

bility and the high level of accuracy of the

generated shaker motion Faithful reproduction

of complex excitations is possible because of the

advanced electronics and control systems used in

this type of shakers Electromagnetic shakers are

not suitable for heavy-duty applications (large test

objects) however High test-input accelerations

are possible at high frequencies when electromag-

netic shakers are used but their displacement and

velocity capabilities are limited to low or

intermediate values (see Table 11)

100

10

1 10 100Excitation Frequency (Hz)

Antiresonance

Resonance

Shak

erD

ispl

acem

entM

agni

tude

Resonance

1000

FIGURE 110 Frequency response curve of a typical

electromagnetic shaker with a test object

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1221 Transient Exciters

Other varieties of exciters are commonly used in

transient-type vibration testing In these tests

either an impulsive force or an initial excitation is

applied to the test object and the resulting

response is monitored The excitations and the

responses are ldquotransientrdquo in this case Hammer

test drop tests and pluck tests fall into this

category For example a hammer test may be

conducted by hitting the object with an instru-

mented hammer and then measuring the response

of the object The hammer has a force sensor at its

tip as sketched in Figure 111 A piezoelectric or

strain-gage type force sensor may be used More

sophisticated hammers have impedance heads in

place of force sensors An impedance head

measures force and acceleration simultaneously

The results of a hammer test will depend on many

factors for example the dynamics of the hammer

body how firmly the hammer is held during the

impact how quickly the impact is applied and

whether there are multiple impacts

13 Control System

The two primary functions of the shaker control system in vibration testing are (1) to guarantee that the

specified excitation is applied to the test object and (2) to ensure that the dynamic stability (motion

constraints) of the test setup is preserved An operational block diagram illustrating these control

functions is given in Figure 112 The reference input to the control system represents the desired

excitation force that should be applied to the test object In the absence of any control however the force

reaching the test object will be distorted primarily because of (1) dynamic interactions and

nonlinearities of the shaker the test table the mounting fixtures the auxiliary instruments and the test

object itself (2) noise and errors in the signal generator amplifiers filters and other equipment and (3)

external loads and disturbances acting on the test object and other components (for example external

restraints aerodynamic forces friction) To compensate for these distorting factors response

measurements (displacements velocities acceleration and so on) are made at various locations in the

test setup and are used to control the system dynamics In particular the responses of the shaker the test

table and the test object are measured These responses are used to compare the actual excitation felt by

FIGURE 111 An instrumented hammer used in bump

tests or hammer tests

ExcitationInput

(Reference)

Feedback Paths

DriveSignal

ShakerResponse

TestTable

TestObject

Test ObjectResponse

Test TableResponseExciter

(Shaker)(Ram)

Controllerand

Amplifier

FIGURE 112 Operational block diagram illustrating a general shaker control system

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copy 2007 by Taylor amp Francis Group LLC

the test object at the shaker interface with the desired (specified) input The drive signal to the shaker is

modified depending on the error that is present

Two types of control are commonly employed in shaker apparatus simple manual control and

complex automatic control Manual control normally consists of simple open-loop trial-and-error

methods of manual adjustments (or calibration) of the control equipment to obtain a desired dynamic

response The actual response is usually monitored (on an oscilloscope or frequency analyzer screen for

example) during manual-control operations The pretest adjustments in manual control can be very

time-consuming as a result the test object might be subjected to overtesting which could produce

cumulative damage is undesirable and could defeat the test purpose Furthermore the calibration

procedure for the experimental setup must be repeated for each new test object

The disadvantages ofmanual control suggest that automatic control is desirable in complex test schemes

in which high accuracy of testing is desired The first step of automatic control involves automatic

measurement of the system response using control sensors and transducers The measurement is then fed

back into the control system which instantaneously determines the best drive signal to actuate the shaker

in order to get the desired excitation This may be done by either analog or digital methods

Primitive control systems require an accurate mathematical description of the test object This

dependency of the control system on the knowledge of test-object dynamics is clearly undesirable

Performance of a good control system should not be considerably affected by the dynamic interactions

and nonlinearities of the test object or by the nature of the excitation Proper selection of feedback signals

and control-system components can reduce such effects and will make the system robust

In the response-spectrum method of vibration testing it is customary to use displacement control at

low frequencies velocity control at intermediate frequency and acceleration control at high frequencies

This necessitates feedback of displacement velocity and acceleration responses Generally however the

most important feedback is the velocity feedback In sine-sweep tests the shaker velocity must change

steadily over the frequency band of interest In particular the velocity control must be precise near the

resonances of the test object Velocity (speed) feedback has a stabilizing effect on the dynamics which is

desirable This effect is particularly useful in ensuring stability in motion when testing is done near

resonances of lightly damped test objects On the contrary displacement (position) feedback can have a

destabilizing effect on some systems particularly when high feedback gains are used

The controller usually consists of various instruments equipment and computation hardware and

software Often the functions of the data-acquisition and processing system overlap with those of the

controller to some extent As an example consider the digital-controller of vibration testing apparatus

First the responses are measured through sensors (and transducers) filtered and amplified

(conditioned) These data channels may be passed through a multiplexer whose purpose is to select

one data channel at a time for processing Most modern data acquisition hardware does not need a

separate multiplexer to handle multiple signals The analog data are converted into digital data using

analog-to-digital converters (ADCs) The resulting sampled data are stored on a disk or as a block data in

the computer memory The reference input signal (typically a signal recorded on an FM tape) is also

sampled (if it is not already in the digital form) using an ADC and fed into the computer Digital

processing is done on the reference signal and the response data with the objective of computing the

command signal to drive the shaker The digital command signal is converted into an analog signal using

a digital-to-analog converter (DAC) and amplified (conditioned) before it is used to drive the exciter

The nature of the control components depends to a large extent on the nature and objectives of the

particular test to be conducted Some of the basic components in a shaker controller are described in

the following subsections

131 Components of a Shaker Controller

1311 Compressor

A compressor circuit is incorporated in automatic excitation control devices to control the excitation-

input level automatically The level of control depends on the feedback signal from a control sensor and

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the specified (reference) excitation signal Usually the compressor circuit is included in the excitation-

signal generator (for example in a sine generator) The control by this means may be done on the basis of

a single-frequency component (eg the fundamental frequency)

1312 Equalizer (Spectrum Shaper)

Random-signal equalizers are used to shape the spectrum of a random signal in a desired manner In

essence and equalizer consists of a bank of narrow-band filters (for example 80 filters) in parallel over

the operating frequency range By passing the signal through each filter the spectral density (or the mean

square value) of the signal in that narrow frequency band (for example each one-third-octave band) is

determined This is compared with the desired spectral level and automatic adjustment is made in that

filter in case there is an error In some systems response-spectrum analysis is made in place of power

spectral density analysis In that case the equalizer consists of a bank of simple oscillators whose

resonant frequencies are distributed over the operating frequency range of the equalizer The feedback

signal is passed through each oscillator and the peak value of its output is determined This value is

compared with the desired response spectrum value at that frequency If there is an error automatic gain

adjustment is made in the appropriate excitation signal components

Random-noise equalizers are used in conjunction with random signal generators They receive

feedback signals from the control sensors In some digital control systems there are algorithms (software)

that are used to iteratively converge the spectrum of the excitation signal felt by the test object into the

desired spectrum

1313 Tracking Filter

Many vibration tests are based on single-frequency excitations In such cases the control functions

should be performed on the basis of the amplitudes of the fundamental-frequency component of the

signal A tracking filter is simply a frequency-tuned band-pass filter It automatically tunes the center

frequency of its very narrow-band-pass filter to the frequency of a carrier signal Then when a noisy

signal is passed through the tuned filter the output of the filter will be the required fundamental

frequency component in the signal Tracking filters also are useful in obtaining amplitudendashfrequency

plots using an XndashY plotter In such cases the frequency value comes from the signal generator (sweep

oscillator) which produces the carrier signal to the tracking filter The tracking filter then determines the

corresponding amplitude of a signal that is fed into it Most tracking filters have dual channels so that two

signals can be handled (tracked) simultaneously

1314 Excitation Controller (Amplitude Servo-Monitor)

An excitation controller is typically an integral part of the signal generator It can be set so that automatic

sweep between two frequency limits can be performed at a selected sweep rate (linear or logarithmic)

More advanced excitation controllers have the capability of an automatic switch-over between constant-

displacement constant-velocity and constant-acceleration excitation-input control at specified

frequencies over the sweep frequency interval Consequently integrator circuits should be present

within the excitation controller unit to determine velocities and displacements from acceleration signals

Sometimes integration is performed by a separate unit called a vibration meter This unit also offers

the operator the capability of selecting the desired level of each signal (acceleration velocity or

displacement) There is an automatic cut-off level for large displacement values that could result from

noise in acceleration signals A compressor is also a subcomponent of the excitation controller The

complete unit is sometimes known as an amplitude servo-monitor

132 Signal-Generating Equipment

Shakers are force-generating devices that are operated using drive (excitation) signals generated from a

source The excitation-signal source is known as the signal generator Three major types of signal

generators are used in vibration testing applications (1) oscillators (2) random-signal generators and

(3) storage devices In some units oscillators and random-signal generators are combined We shall

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53191mdash522007mdash1202mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

discuss these two generators separately however because of their difference in function It also should be

noted that almost any digital signal (deterministic or random) can be generated by a digital computer

using a suitable computer program the signal eventually can be passed through a DAC to obtain

the corresponding analog signal These lsquodigitalrsquo signal generators along with analog sources such as

magnetic tape players (FM) are classified into the category of storage devices

The dynamic range of equipment is the ratio of the maximum and minimum output levels (expressed

in decibels) at which it is capable of operating without significant error This is an important specification

for many types of equipment particularly for signal-generating devices The output level of the signal

generator should be set to a value within its dynamic range

1321 Oscillators

Oscillators are essentially single-frequency generators Typically sine signals are generated but other

waveforms (such as rectangular and triangular pulses) are also available in most oscillators Normally

an oscillator has two modes of operation (1) sweeping up and down between two frequency limits and

(2) dwelling at a specified frequency In the sweep operation the sweep rate should be specified This can

be done either on a linear scale (Hzmin) or on a logarithmic scale (octavesmin) In the dwell operation

the frequency points (or intervals) should be specified In either case a desired signal level can be chosen

using the gain-control knob An oscillator that is operated exclusively in the sweep mode is called a sweep

oscillator

The early generation of oscillators employed variable inductor-capacitor types of electronic circuits to

generate signals oscillating at a desired frequency The oscillator is tuned to the required frequency by

varying the capacitance or inductance parameters A DC voltage is applied to energize the capacitor

and to obtain the desired oscillating voltage signal which subsequently is amplified and conditioned

Modern oscillators use operational amplifier circuits along with resistor capacitor and semiconductor

(SC) elements Also common are crystal (quartz) parallel-resonance oscillators used to generate voltage

signals accurately at a fixed frequency The circuit is activated using a DC-voltage source Other

frequencies of interest are obtained by passing this high-frequency signal through a frequency converter

The signal is then conditioned (amplified and filtered) Required shaping (for example rectangular

pulse) is obtained using a shape circuit Finally the required signal level is obtained by passing the

resulting signal through a variable-gain amplifier A block diagram of an oscillator illustrating various

stages in the generation of a periodic signal is given in Figure 113

A typical oscillator offers a choice of several (typically six) linear and logarithmic frequency ranges and

a sizable level of control capability (for example 80 dB) Upper and lower frequency limits in a sweep can

be preset on the front panel to any of the available frequency ranges Sweep-rate settings are continuously

DC Voltage

Oscillator

FrequencySpecification

FrequencyConverter

FilterAmplifier

ShaperPeriodicSignal

FrequencyCounter

Fixed-FrequencySignal

Variable-GainOutput

Amplifier

SignalSpecification

LevelSpecification

FIGURE 113 Block diagram of an oscillator-type signal generator

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copy 2007 by Taylor amp Francis Group LLC

  • 53191fm
    • Vibration Monitoring Testing and Instrumentation
      • Preface
      • Acknowledgments
      • Editor-in-Chief
      • Contributors
      • Contents
      • Related Titles
          • 53191ch1
            • Table of Contents
            • Chapter 1 Vibration Instrumentation
              • Summary
              • 11 Introduction
              • 12 Vibration Exciters
                • 121 Shaker Selection
                  • 1211 Force Rating
                  • 1212 Power Rating
                  • 1213 Stroke Rating
                  • 1214 Hydraulic Shakers
                  • 1215 Inertial Shakers
                  • 1216 Electromagnetic Shakers
                    • 122 Dynamics of Electromagnetic Shakers
                      • 1221 Transient Exciters
                          • 13 Control System
                            • 131 Components of a Shaker Controller
                              • 1311 Compressor
                              • 1312 Equalizer (Spectrum Shaper)
                              • 1313 Tracking Filter
                              • 1314 Excitation Controller (Amplitude Servo-Monitor)
                                • 132 Signal-Generating Equipment
                                  • 1321 Oscillators
                                  • 1322 Random Signal Generators
                                  • 1323 Tape Players
                                  • 1324 Data Processing
                                      • 14 Performance Specification
                                        • 141 Parameters for Performance Specification
                                          • 1411 Time-Domain Specifications
                                          • 1412 Frequency-Domain Specifications
                                            • 142 Linearity
                                            • 143 Instrument Ratings
                                              • 1431 Rating Parameters
                                                • 144 Accuracy and Precision
                                                  • 15 Motion Sensors and Transducers
                                                    • 151 Potentiometer
                                                      • 1511 Potentiometer Resolution
                                                      • 1512 Optical Potentiometer
                                                        • 152 Variable-Inductance Transducers
                                                          • 1521 Mutual-Induction Transducers
                                                          • 1522 Linear-Variable Differential Transformer
                                                          • 1523 Signal Conditioning
                                                            • 153 Mutual-Induction Proximity Sensor
                                                            • 154 Selfinduction Transducers
                                                            • 155 Permanent-Magnet Transducers
                                                            • 156 Alternating Current Permanent-Magnet Tachometer
                                                            • 157 Alternating Current Induction Tachometer
                                                            • 158 Eddy Current Transducers
                                                            • 159 Variable-Capacitance Transducers
                                                              • 1591 Capacitive Displacement Sensors
                                                              • 1592 Capacitive Angular Velocity Sensor
                                                              • 1593 Capacitance Bridge Circuit
                                                                • 1510 Piezoelectric Transducers
                                                                  • 15101 Sensitivity
                                                                  • 15102 Piezoelectric Accelerometer
                                                                  • 15103 Charge Amplifier
                                                                      • 16 Torque Force and Other Sensors
                                                                        • 161 Strain Gage Sensors
                                                                          • 1611 Equations for Strain Gage Measurements
                                                                          • 1612 Bridge Sensitivity
                                                                          • 1613 The Bridge Constant
                                                                          • 1614 The Calibration Constant
                                                                          • 1615 Data Acquisition
                                                                          • 1616 Accuracy Considerations
                                                                          • 1617 Semiconductor Strain Gages
                                                                          • 1618 Force and Torque Sensors
                                                                          • 1619 Strain Gage Torque Sensors
                                                                          • 16110 Deflection Torque Sensors
                                                                          • 16111 Variable-Reluctance Torque Sensor
                                                                          • 16112 Reaction Torque Sensors
                                                                            • 162 Miscellaneous Sensors
                                                                              • 1621 Stroboscope
                                                                              • 1622 Fiber Optic Sensors and Lasers
                                                                              • 1623 Fiber-Optic Gyroscope
                                                                              • 1624 Laser Doppler Interferometer
                                                                              • 1625 Ultrasonic Sensors
                                                                              • 1626 Gyroscopic Sensors
                                                                                  • References
                                                                                  • Appendix 1A Virtual Instrumentation for Data Acquisition Analysis and Presentation
                                                                                    • Summary
                                                                                    • List of Abbreviations
                                                                                    • 1A1 Dynamic Signals
                                                                                      • 1A11 Acquiring and Simulating Dynamic Signals
                                                                                        • 1A111 Aliasing
                                                                                        • 1A112 Time Continuity
                                                                                            • 1A2 Measurement Configuration Considerations
                                                                                              • 1A21 Input Signal Considerations
                                                                                                • 1A211 Input Pseudodifferential and Differential Configuration
                                                                                                • 1A212 Gain
                                                                                                • 1A213 Input Coupling
                                                                                                • 1A214 Integrated Electronic Piezoelectric Excitation
                                                                                                • 1A215 Nyquist Frequency and Bandwidth
                                                                                                • 1A216 Analog-to-Digital Conversion
                                                                                                • 1A217 Antialias Filters
                                                                                                • 1A218 Input Filter Delay
                                                                                                • 1A219 Overload Detection
                                                                                                  • 1A22 Output Signal Considerations
                                                                                                    • 1A221 Output Pseudodifferential and Differential Configuration
                                                                                                    • 1A222 Attenuation
                                                                                                    • 1A223 Digital-to-Analog Conversion
                                                                                                    • 1A224 Anti-imaging and Interpolation Filters
                                                                                                    • 1A225 Output Filter Delay
                                                                                                        • 1A3 Scaling and Calibration
                                                                                                          • 1A31 Scaling to Engineering Units
                                                                                                          • 1A32 Performing System Calibration
                                                                                                            • 1A321 Propagation Delay Calibration
                                                                                                                • 1A4 Limit Testing Analysis
                                                                                                                  • 1A41 Limit Testing Overview
                                                                                                                  • 1A42 Using the SVT Limit Testing VI
                                                                                                                    • 1A5 Integration
                                                                                                                      • 1A51 Introduction to Integration
                                                                                                                      • 1A52 Implementing Integration
                                                                                                                        • 1A521 Challenges when Integrating Vibration Data
                                                                                                                          • 1A53 Time-Domain Integration
                                                                                                                            • 1A531 Single-Shot Acquisition and Integration
                                                                                                                            • 1A532 Continuous Acquisition and Integration
                                                                                                                              • 1A54 Frequency-Domain Integration
                                                                                                                                • 1A6 Vibration-Level Measurements
                                                                                                                                  • 1A61 Measuring the Root Mean Square Level
                                                                                                                                    • 1A611 Single-Shot Buffered Acquisition
                                                                                                                                    • 1A612 Continuous Signal Acquisition
                                                                                                                                      • 1A62 Performing a Running RMS Level Measurement
                                                                                                                                      • 1A63 Computing the Peak Level
                                                                                                                                      • 1A64 Computing the Crest Factor
                                                                                                                                        • 1A7 Frequency Analysis
                                                                                                                                          • 1A71 FFT Fundamentals
                                                                                                                                            • 1A711 Number of Samples
                                                                                                                                            • 1A712 Frequency Resolution
                                                                                                                                            • 1A713 Maximum Resolvable Frequency
                                                                                                                                            • 1A714 Minimum Resolvable Frequency
                                                                                                                                            • 1A715 Number of Spectral Lines
                                                                                                                                            • 1A716 Relationship between Time-Domain and Frequency-Domain Specifications and Parameters
                                                                                                                                              • 1A72 Increasing Frequency Resolution
                                                                                                                                                • 1A721 Zoom FFT Analysis
                                                                                                                                                • 1A722 Frequency Resolution of the Zoom FFT VIs
                                                                                                                                                • 1A723 Zoom Measurement
                                                                                                                                                • 1A724 Zoom Settings
                                                                                                                                                • 1A725 Subset Analysis
                                                                                                                                                    • 1A8 Transient Analysis
                                                                                                                                                      • 1A81 Transient Analysis with the Sound and Vibration Toolkit
                                                                                                                                                      • 1A82 Performing an STFT vs Time
                                                                                                                                                        • 1A821 Selecting the FFT Block Size
                                                                                                                                                        • 1A822 Overlapping
                                                                                                                                                        • 1A823 Using the SVT STFT vs Time VI
                                                                                                                                                          • 1A83 Performing an STFT vs Rotational Speed
                                                                                                                                                            • 1A831 Converting the Pulse Train to Rotational Speed
                                                                                                                                                            • 1A832 STFT vs RPM
                                                                                                                                                              • 1A84 Measuring a Shock Response Spectrum
                                                                                                                                                                • 1A9 Waterfall Display
                                                                                                                                                                  • 1A91 Using the Display VIs
                                                                                                                                                                    • 1A911 Initializing the Display
                                                                                                                                                                    • 1A912 Sending Data to the Display
                                                                                                                                                                    • 1A913 Waterfall Display for Frequency Analysis
                                                                                                                                                                    • 1A914 Waterfall Display for Transient Analysis
                                                                                                                                                                    • 1A915 Waterfall Display for Octave Spectra
                                                                                                                                                                        • 1A10 Swept-Sine Measurements
                                                                                                                                                                          • 1A101 Swept-Sine Overview
                                                                                                                                                                          • 1A102 Choosing Swept-Sine vs FFT Measurements
                                                                                                                                                                          • 1A103 Taking a Swept-Sine Measurement
                                                                                                                                                                          • 1A104 Swept-Sine Measurement Example
                                                                                                                                                                              • Bibliography
                                                                                                                                                                              • Related Titles
                                                                                                                                                                                  • 53191ch2
                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                    • Chapter 2 Signal Conditioning and Modification
                                                                                                                                                                                      • Summary
                                                                                                                                                                                      • 21 Introduction
                                                                                                                                                                                      • 22 Amplifiers
                                                                                                                                                                                        • 221 Operational Amplifier
                                                                                                                                                                                        • 222 Use of Feedback in Opamp
                                                                                                                                                                                        • 223 Voltage Current and Power Amplifiers
                                                                                                                                                                                          • 2231 Charge Amplifiers
                                                                                                                                                                                            • 224 Instrumentation Amplifiers
                                                                                                                                                                                              • 2241 Differential Amplifier
                                                                                                                                                                                              • 2242 Common Mode
                                                                                                                                                                                                • 225 Amplifier Performance Ratings
                                                                                                                                                                                                  • 2251 Common-Mode Rejection Ratio
                                                                                                                                                                                                    • 226 Component Interconnection
                                                                                                                                                                                                      • 2261 Impedance Characteristics
                                                                                                                                                                                                      • 2262 Cascade Connection of Devices
                                                                                                                                                                                                      • 2263 AC-Coupled Ampliers
                                                                                                                                                                                                          • 23 Analog Filters
                                                                                                                                                                                                            • 231 Passive Filters and Active Filters
                                                                                                                                                                                                              • 2311 Number of Poles
                                                                                                                                                                                                                • 232 Low-Pass Filters
                                                                                                                                                                                                                  • 2321 Low-Pass Butterworth Filter
                                                                                                                                                                                                                    • 233 High-Pass Filters
                                                                                                                                                                                                                    • 234 Band-Pass Filters
                                                                                                                                                                                                                      • 2341 Resonance-Type Band-Pass Filters
                                                                                                                                                                                                                        • 235 Band-Reject Filters
                                                                                                                                                                                                                          • 24 Modulators and Demodulators
                                                                                                                                                                                                                            • 241 Amplitude Modulation
                                                                                                                                                                                                                              • 2411 Modulation Theorem
                                                                                                                                                                                                                              • 2412 Side Frequencies and Side Bands
                                                                                                                                                                                                                                • 242 Application of Amplitude Modulation
                                                                                                                                                                                                                                  • 2421 Fault Detection and Diagnosis
                                                                                                                                                                                                                                    • 243 Demodulation
                                                                                                                                                                                                                                      • 25 Analog ndashDigital Conversion
                                                                                                                                                                                                                                        • 251 Digital-to-Analog Conversion
                                                                                                                                                                                                                                          • 2511 DAC Error Sources
                                                                                                                                                                                                                                            • 252 Analog-to-Digital Conversion
                                                                                                                                                                                                                                            • 253 Analog-to-Digital Converter Performance Characteristics
                                                                                                                                                                                                                                              • 2531 Resolution and Quantization Error
                                                                                                                                                                                                                                              • 2532 Monotonicity Nonlinearity and Offset Error
                                                                                                                                                                                                                                              • 2533 Analog-to-Digital Converter Conversion Rate
                                                                                                                                                                                                                                                • 254 Sample-and-Hold Circuitry
                                                                                                                                                                                                                                                • 255 Digital Filters
                                                                                                                                                                                                                                                  • 2551 Software Implementation and Hardware Implementation
                                                                                                                                                                                                                                                      • 26 Bridge Circuits
                                                                                                                                                                                                                                                        • 261 Wheatstone Bridge
                                                                                                                                                                                                                                                        • 262 Constant-Current Bridge
                                                                                                                                                                                                                                                        • 263 Bridge Amplifiers
                                                                                                                                                                                                                                                          • 2631 Half-Bridge Circuits
                                                                                                                                                                                                                                                            • 264 Impedance Bridges
                                                                                                                                                                                                                                                              • 2641 Owen Bridge
                                                                                                                                                                                                                                                              • 2642 Wien-Bridge Oscillator
                                                                                                                                                                                                                                                                  • 27 Linearizing Devices
                                                                                                                                                                                                                                                                    • 271 Linearization by Software
                                                                                                                                                                                                                                                                    • 272 Linearization by Hardware Logic
                                                                                                                                                                                                                                                                    • 273 Analog Linearizing Circuitry
                                                                                                                                                                                                                                                                    • 274 Offsetting Circuitry
                                                                                                                                                                                                                                                                    • 275 Proportional-Output Circuitry
                                                                                                                                                                                                                                                                      • 2751 Curve-Shaping Circuitry
                                                                                                                                                                                                                                                                          • 28 Miscellaneous Signal Modification Circuitry
                                                                                                                                                                                                                                                                            • 281 Phase Shifters
                                                                                                                                                                                                                                                                            • 282 Voltage-to-Frequency Converter
                                                                                                                                                                                                                                                                            • 283 Frequency-to-Voltage Converter
                                                                                                                                                                                                                                                                            • 284 Voltage-to-Current Converters
                                                                                                                                                                                                                                                                            • 285 Peak-Hold Circuits
                                                                                                                                                                                                                                                                              • 29 Signal Analyzers and Display Devices
                                                                                                                                                                                                                                                                                • 291 Signal Analyzers
                                                                                                                                                                                                                                                                                • 292 Oscilloscopes
                                                                                                                                                                                                                                                                                  • 2921 Triggering
                                                                                                                                                                                                                                                                                  • 2922 Lissajous Patterns
                                                                                                                                                                                                                                                                                  • 2923 Digital Oscilloscopes
                                                                                                                                                                                                                                                                                      • Bibliography
                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                          • 53191ch3
                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                            • Chapter 3 Vibration Testing
                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                              • 31 Introduction
                                                                                                                                                                                                                                                                                              • 32 Representation of a Vibration Environment
                                                                                                                                                                                                                                                                                                • 321 Test Signals
                                                                                                                                                                                                                                                                                                  • 3211 Stochastic vs Deterministic Signals
                                                                                                                                                                                                                                                                                                    • 322 Deterministic Signal Representation
                                                                                                                                                                                                                                                                                                      • 3221 Single-Frequency Signals
                                                                                                                                                                                                                                                                                                      • 3222 Sine Sweep
                                                                                                                                                                                                                                                                                                      • 3223 Sine Dwell
                                                                                                                                                                                                                                                                                                      • 3224 Decaying Sine
                                                                                                                                                                                                                                                                                                      • 3225 Sine Beat
                                                                                                                                                                                                                                                                                                      • 3226 Sine Beat with Pauses
                                                                                                                                                                                                                                                                                                      • 3227 Multifrequency Signals
                                                                                                                                                                                                                                                                                                      • 3228 Actual Excitation Records
                                                                                                                                                                                                                                                                                                      • 3229 Simulated Excitation Signals
                                                                                                                                                                                                                                                                                                        • 323 Stochastic Signal Representation
                                                                                                                                                                                                                                                                                                          • 3231 Ergodic Random Signals
                                                                                                                                                                                                                                                                                                          • 3232 Stationary Random Signals
                                                                                                                                                                                                                                                                                                          • 3233 Independent and Uncorrelated Signals
                                                                                                                                                                                                                                                                                                          • 3234 Transmission of Random Excitations
                                                                                                                                                                                                                                                                                                            • 324 Frequency-Domain Representations
                                                                                                                                                                                                                                                                                                              • 3241 Fourier Spectrum Method
                                                                                                                                                                                                                                                                                                              • 3242 Power Spectral Density Method
                                                                                                                                                                                                                                                                                                                • 325 Response Spectrum
                                                                                                                                                                                                                                                                                                                  • 3251 Displacement Velocity and Acceleration Spectra
                                                                                                                                                                                                                                                                                                                  • 3252 Response-Spectra Plotting Paper
                                                                                                                                                                                                                                                                                                                  • 3253 Zero-Period Acceleration
                                                                                                                                                                                                                                                                                                                  • 3254 Uses of Response Spectra
                                                                                                                                                                                                                                                                                                                    • 326 Comparison of Various Representations
                                                                                                                                                                                                                                                                                                                      • 33 Pretest Procedures
                                                                                                                                                                                                                                                                                                                        • 331 Purpose of Testing
                                                                                                                                                                                                                                                                                                                        • 332 Service Functions
                                                                                                                                                                                                                                                                                                                          • 3321 Active Equipment
                                                                                                                                                                                                                                                                                                                          • 3322 Passive Equipment
                                                                                                                                                                                                                                                                                                                          • 3323 Functional Testing
                                                                                                                                                                                                                                                                                                                            • 333 Information Acquisition
                                                                                                                                                                                                                                                                                                                              • 3331 Interface Details
                                                                                                                                                                                                                                                                                                                              • 3332 Effect of Neglecting Interface Dynamics
                                                                                                                                                                                                                                                                                                                              • 3333 Effects of Damping
                                                                                                                                                                                                                                                                                                                              • 3334 Effects of Inertia
                                                                                                                                                                                                                                                                                                                              • 3335 Effect of Natural Frequency
                                                                                                                                                                                                                                                                                                                              • 3336 Effect of Excitation Frequency
                                                                                                                                                                                                                                                                                                                              • 3337 Other Effects of Interface
                                                                                                                                                                                                                                                                                                                                • 334 Test-Program Planning
                                                                                                                                                                                                                                                                                                                                  • 3341 Testing of Cabinet-Mounted Equipment
                                                                                                                                                                                                                                                                                                                                    • 335 Pretest Inspection
                                                                                                                                                                                                                                                                                                                                      • 34 Testing Procedures
                                                                                                                                                                                                                                                                                                                                        • 341 Resonance Search
                                                                                                                                                                                                                                                                                                                                        • 342 Methods of Determining Frequency-Response Functions
                                                                                                                                                                                                                                                                                                                                          • 3421 Fourier Transform Method
                                                                                                                                                                                                                                                                                                                                          • 3422 Spectral Density Method
                                                                                                                                                                                                                                                                                                                                          • 3423 Harmonic Excitation Method
                                                                                                                                                                                                                                                                                                                                            • 343 Resonance-Search Test Methods
                                                                                                                                                                                                                                                                                                                                              • 3431 Hammer (Bump) Test and Drop Test
                                                                                                                                                                                                                                                                                                                                              • 3432 Pluck Test
                                                                                                                                                                                                                                                                                                                                              • 3433 Shaker Tests
                                                                                                                                                                                                                                                                                                                                                • 344 Mechanical Aging
                                                                                                                                                                                                                                                                                                                                                  • 3441 Equivalence for Mechanical Aging
                                                                                                                                                                                                                                                                                                                                                  • 3442 Excitation-Intensity Equivalence
                                                                                                                                                                                                                                                                                                                                                  • 3443 Dynamic-Excitation Equivalence
                                                                                                                                                                                                                                                                                                                                                  • 3444 Cumulative Damage Theory
                                                                                                                                                                                                                                                                                                                                                    • 345 Test-Response Spectrum Generation
                                                                                                                                                                                                                                                                                                                                                    • 346 Instrument Calibration
                                                                                                                                                                                                                                                                                                                                                    • 347 Test-Object Mounting
                                                                                                                                                                                                                                                                                                                                                    • 348 Test-Input Considerations
                                                                                                                                                                                                                                                                                                                                                      • 3481 Test Nomenclature
                                                                                                                                                                                                                                                                                                                                                      • 3482 Testing with Uncorrelated Excitations
                                                                                                                                                                                                                                                                                                                                                      • 3483 Symmetrical Rectilinear Testing
                                                                                                                                                                                                                                                                                                                                                      • 3484 Geometry vs Dynamics
                                                                                                                                                                                                                                                                                                                                                      • 3485 Some Limitations
                                                                                                                                                                                                                                                                                                                                                      • 3486 Testing Black Boxes
                                                                                                                                                                                                                                                                                                                                                      • 3487 Phasing of Excitations
                                                                                                                                                                                                                                                                                                                                                      • 3488 Testing a Gray or White Box
                                                                                                                                                                                                                                                                                                                                                      • 3489 Overtesting in Multitest Sequences
                                                                                                                                                                                                                                                                                                                                                          • 35 Some Practical Information
                                                                                                                                                                                                                                                                                                                                                            • 351 Random Vibration Test Example
                                                                                                                                                                                                                                                                                                                                                            • 352 Vibration Shakers and Control Systems
                                                                                                                                                                                                                                                                                                                                                              • Bibliography
                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                  • 53191ch4
                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                    • Chapter 4 Experimental Modal Analysis
                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                      • 41 Introduction
                                                                                                                                                                                                                                                                                                                                                                      • 42 Frequency-Domain Formulation
                                                                                                                                                                                                                                                                                                                                                                        • 421 Transfer-Function Matrix
                                                                                                                                                                                                                                                                                                                                                                        • 422 Principle of Reciprocity
                                                                                                                                                                                                                                                                                                                                                                          • 43 Experimental Model Development
                                                                                                                                                                                                                                                                                                                                                                            • 431 Extraction of the Time-Domain Model
                                                                                                                                                                                                                                                                                                                                                                              • 44 Curve Fitting of Transfer Functions
                                                                                                                                                                                                                                                                                                                                                                                • 441 Problem Identification
                                                                                                                                                                                                                                                                                                                                                                                • 442 Single- and Multi-Degree-of-Freedom Techniques
                                                                                                                                                                                                                                                                                                                                                                                • 443 Single-Degree-of-Freedom Parameter Extraction in the Frequency Domain
                                                                                                                                                                                                                                                                                                                                                                                  • 4431 Circle-Fit Method
                                                                                                                                                                                                                                                                                                                                                                                    • Case of Viscous Damping
                                                                                                                                                                                                                                                                                                                                                                                    • Case of Hysteretic Damping
                                                                                                                                                                                                                                                                                                                                                                                      • 4432 Peak-Picking Method
                                                                                                                                                                                                                                                                                                                                                                                        • 444 Multi-Degree of Freedom Curve Fitting
                                                                                                                                                                                                                                                                                                                                                                                          • 4441 Formulation of the Method
                                                                                                                                                                                                                                                                                                                                                                                            • 445 A Comment on Static Modes and Rigid-Body Modes
                                                                                                                                                                                                                                                                                                                                                                                            • 446 Residue Extraction
                                                                                                                                                                                                                                                                                                                                                                                              • 45 Laboratory Experiments
                                                                                                                                                                                                                                                                                                                                                                                                • 451 Lumped-Parameter System
                                                                                                                                                                                                                                                                                                                                                                                                  • 4511 Frequency-Domain Test
                                                                                                                                                                                                                                                                                                                                                                                                  • 4512 Time-Domain Tests
                                                                                                                                                                                                                                                                                                                                                                                                    • 452 Distributed-Parameter System
                                                                                                                                                                                                                                                                                                                                                                                                      • 46 Commercial EMA Systems
                                                                                                                                                                                                                                                                                                                                                                                                        • 461 System Configuration
                                                                                                                                                                                                                                                                                                                                                                                                          • 4611 FFT Analysis Options
                                                                                                                                                                                                                                                                                                                                                                                                          • 4612 Modal Analysis Components
                                                                                                                                                                                                                                                                                                                                                                                                              • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                  • 53191ch5
                                                                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                    • Chapter 5 Mechanical Shock
                                                                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                      • 51 Definitions
                                                                                                                                                                                                                                                                                                                                                                                                                        • 511 Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 512 Simple (or Perfect) Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 513 Half-Sine Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 514 Versed-Sine (or Haversine) Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 515 Terminal Peak Sawtooth Shock or Final Peak Sawtooth Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 516 Rectangular Shock
                                                                                                                                                                                                                                                                                                                                                                                                                          • 5161 Trapezoidal Shock
                                                                                                                                                                                                                                                                                                                                                                                                                              • 52 Description in the Time Domain
                                                                                                                                                                                                                                                                                                                                                                                                                              • 53 Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                • 531 Need
                                                                                                                                                                                                                                                                                                                                                                                                                                • 532 Shock Response Spectrum Definition
                                                                                                                                                                                                                                                                                                                                                                                                                                • 533 Response of a Linear One-Degree-of-Freedom System
                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5331 Shock Defined by a Force
                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5332 Shock Defined by an Acceleration
                                                                                                                                                                                                                                                                                                                                                                                                                                    • 534 Definitions
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5341 Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5342 Absolute Acceleration Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5343 Relative Displacement Shock Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5344 Primary Positive Shock Response Spectrum or Initial Positive Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5345 Primary (or Initial) Negative Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5346 Secondary (or Residual) Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5347 Positive (or Maximum Positive) Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5348 Negative (or Maximum Negative) Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5349 Maximax Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53410 Choice of Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                        • 535 Standardized Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5351 Definition
                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5352 Standardized Shock Response Spectra of Simple Shocks
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53521 Half-Sine Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53522 Versed Sine Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53523 Terminal Peak Sawtooth Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53524 Rectangular Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53525 Trapezoidal Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 536 Choice of Damping
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 537 Shock Response Spectra Domains
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 538 Algorithms for Calculation of the Shock Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 539 Choice of the Digitization Frequency of the Signal
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5310 Use of Shock Response Spectra for the Study of Systems with Several Degrees of Freedom
                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 54 Pyroshocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 55 Use of Shock Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 551 Severity Comparison of Several Shocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 552 Test Specification Development from Real Environment Data
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5521 Synthesis of Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5522 Nature of the Specification
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5523 Choice of Shape
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5524 Amplitude
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5525 Duration
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5526 Difficulties
                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 56 Standards
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 561 Types of Standards
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 562 Installation Conditions of Test Item
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 563 Uncertainty Factor
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 564 Bump Test
                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 57 Damage Boundary Curve
                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 571 Definition
                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 572 Analysis of Test Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 58 Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 581 Main Types
                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 582 Impact Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5821 Universal Shock-Test Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 58211 Impact Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 58212 Impulse Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 583 Shock Simulators (Programmers)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5831 Half-Sine Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58311 Shock Duration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58312 Impact Velocity
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58313 Maximum Deformation of the Shock Simulator (Programmer)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58314 Shock Amplitude
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58315 Characteristics of the Target
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5832 Terminal Peak Sawtooth Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5833 Rectangular Pulse ndash Trapezoidal Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5834 Universal Shock Simulator (Programmer)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 58341 Generating a Half-Sine Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 58342 Generating a Terminal Peak Sawtooth Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 58343 Trapezoidal Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 584 Limitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5841 Limitations of the Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5842 Limitations of Shock Simulators
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 585 Pneumatic Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 586 High Impact Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5861 Lightweight High Impact Shock Machine
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5862 Medium Weight High Impact Shock Machine
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 587 Specific Test Facilities
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 59 Generation of Shock Using Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 591 Principle Behind the Generation of a Simple Shape Signal versus Time
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 592 Main Advantages
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 593 Pre- and Postshocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5931 Requirements
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5932 Solutions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 59321 Optimized Pre- and Postpulses
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5933 Incidence on the Shock Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 594 Limitations of Electrodynamic Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5941 Mechanical Limitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 59411 Abacuses
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5942 Electronic Limitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 595 The Use of Electrohydraulic Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 510 Control by a Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 5101 Principle
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 5102 Principal Shapes of Elementary Signals
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 51021 Decaying Sinusoid
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 51022 ZERD Function
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 51023 WAVSIN Waveform
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 5103 Comparison of WAVSIN SHOC Waveforms and Decaying Sinusoid
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 5104 Criticism of Control by a Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 511 Pyrotechnic Shock Simulation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5111 Simulation Using Pyrotechnic Facilities
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5112 Simulation Using Metal-to-Metal Impact
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5113 Simulation Using Electrodynamic Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5114 Simulation Using Conventional Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53191ch6
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Chapter 6 Machine Condition Monitoring and Fault Diagnostics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 61 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 62 Machinery Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 621 Causes of Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 622 Types of Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 623 Frequency of Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 63 Basic Maintenance Strategies
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 631 Run-to-Failure (Breakdown) Maintenance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 632 Scheduled (Preventative) Maintenance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 633 Condition-Based (Predictive Proactive Reliability Centered On-Condition) Maintenance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 64 Factors Which Influence Maintenance Strategy
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 65 Machine Condition Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 651 Periodic Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 652 Continuous Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 66 Transducer Selection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 661 Noncontact Displacement Transducers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 662 Velocity Transducers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 663 Acceleration Transducers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 67 Transducer Location
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 68 Recording and Analysis Instrumentation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 681 Vibration Meters
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 682 Data Collectors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 683 Frequency-Domain Analyzers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 684 Time-Domain Instruments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 685 Tracking Analyzers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 69 Display Formats and Analysis Tools
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 691 Time Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6911 Time-Waveform Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6912 Time-Waveform Indices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6913 Time-Synchronous Averaging
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6914 Negative Averaging
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6915 Orbits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6916 Probability Density Functions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6917 Probability Density Moments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 692 Frequency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6921 Band-Pass Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6922 Shock Pulse (Spike Energy)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6923 Enveloped Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6924 Signature Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6925 Cascades (Waterfall Plots)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6926 Masks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6927 Frequency-Domain Indices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 693 Modal Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 694 Quefrency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 610 Fault Detection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 6101 Standards
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61011 Standards Based on Machinery Type
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61012 Standards Based on Vibration Severity
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 6102 Acceptance Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 61021 Statistical Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 6103 Frequency-Domain Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61031 Limited Band Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61032 Constant Bandwidth Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61033 Constant Percentage Bandwidth Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 611 Fault Diagnostics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 6111 Forcing Functions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61111 Unbalance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61112 Misalignment
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61113 Mechanical Looseness
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61114 Soft Foot
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61115 Rubs
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61116 Resonances
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61117 Oil Whirl
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61118 Oil Whip
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61119 Structural Vibrations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 611110 Foundation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 6112 Specific Machine Components
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 61121 Damaged or Worn Rolling-Element Bearings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 61122 Damaged or Worn Gears
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 6113 Specific Machine Types
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61131 Pumps
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61132 Fans
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61133 Electric Motors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61134 Steam and Gas Turbines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61135 Compressors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61136 Reciprocating Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 6114 Advanced Fault Diagnostic Techniques
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 53191ch7
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • Chapter 7 Vibration-Based Tool Condition Monitoring Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 71 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 72 Mechanics of Turning
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 721 General Terms
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 722 Chatter Vibrations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 723 Tool Wear
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7231 Tool Failure Mechanisms
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7232 Tool Failure Modes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7233 Tool Wear Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7234 Tool Wear Stages
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 73 Vibration Signal Recording
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 731 Direct and Indirect Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 732 Sensor Requirements for Tool Wear Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 733 Force Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7331 Direct Measurement Dynamometers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7332 Indirect Force Sensors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7333 Piezoelectric Strain Sensors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7334 Resistance Strain Gauges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7335 Customized Force Sensors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 734 Acceleration Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 735 Acoustic Emission Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 736 Sensor Comparisons
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 74 Signal Processing for Sensor-Based Tool Condition Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 741 Feature Extraction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7411 Time Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7412 Frequency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7413 Statistical Processing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7414 TimendashFrequency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 742 Feature Selection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 75 Wear ModelDecision-Making for Sensor-Based Tool Condition Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 751 Trending Threshold
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 752 Neural Networks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7521 Unsupervised Networks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7522 Supervised Networks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 753 Fuzzy Logic
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 754 Other Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 76 Conclusion
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53191ch8
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Chapter 8 Fault Diagnosis of Helicopter Gearboxes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 81 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 82 Abnormality Scaling
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 83 The Structure-Based Connectionist Network
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 84 Sensor Location Selection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 841 Coverage Index
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 842 Overlap Index
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 843 Monitoring Effectiveness
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 85 A Case Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 851 Structural and Featural Influences
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 852 Evaluation of Influences
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 853 Fault Detection Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 854 Fault Diagnostic Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 8541 Faulty Subsystem Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 8542 Faulty Component Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 855 Sensor Location Evaluation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 856 Sensor Location Validation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 86 Conclusion
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 53191ch9
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Chapter 9 Vibration Suppression and Monitoring in Precision Motion Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 91 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 92 Mechanical Design to Minimize Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 921 Stability and Static Determinacy of Machine Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 922 Two-Dimensional Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 923 Three-Dimensional Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 93 Adaptive Notch Filter
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 931 Fast Fourier Transform
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 932 Simulation and Experiments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 94 Real-Time Vibration Analyzer
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 941 Learning Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 942 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 943 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 944 Experiments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 9441 Input Variables mdash the Evaluation Criteria
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 94411 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 94412 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 9442 Evaluation Rules
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 94421 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 94422 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 9443 Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 94431 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 94432 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 95 Practical Insights and Case Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 96 Conclusions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 53191ch10
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Chapter 10 Vibration and Shock Problems of Civil Engineering Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 101 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 102 Earthquake-Induced Vibration of Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1021 Seismicity and Ground Motions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1022 Influence of Local Site Conditions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1023 Response of Structures to Ground Motions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1024 Dynamic Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10241 Equations of Motion for Linear Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10242 Equations of Motion for Linear Multiple-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1025 Earthquake Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10251 Elastic Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10252 Smoothed Design Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10253 Ductility-Modified Response Spectrum Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1026 Design Philosophy and the Code Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10261 Performance-Based Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1027 Analysis Options for Earthquake Effects
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10271 Dynamic Time History Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10272 Response Spectrum Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 102721 Response Spectrum Analysis of Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 102722 Response Spectrum Analysis of Multi-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10273 Equivalent Static Analysis (Force-Based Approach)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10274 Displacement-Based Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1028 SoilndashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1029 Active and Passive Control Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 10210 Worked Examples
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 103 Dynamic Effects of Wind Loading on Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1031 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1032 Wind Speed
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1033 Design Structures for Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10331 Types of Wind Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10332 Design Criteria
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10333 Static Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1034 Along and Across-Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10341 Along-Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10342 Across-Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1035 Wind Tunnel Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1036 Comfort Criteria Human Response to Building Motion
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1037 Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1038 Comparison with Earthquake Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 104 Vibrations Due to Fluid ndashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1041 Added Mass and Inertial Coupling
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1042 Wave-Induced Vibration of Structure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 105 Blast Loading and Blast Effects on Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1051 Explosions and Blast Phenomenon
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1052 Explosive Air-Blast Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10521 Blast Wave Scaling Laws
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10522 Prediction of Blast Pressure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1053 Gas Explosion Loading and Effect of Internal Explosions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1054 Structural Response to Blast Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10541 Elastic Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10542 Elasto-Plastic Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1055 Material Behaviors at High Strain Rate
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10551 Dynamic Properties of Concrete under High Strain Rates
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10552 Dynamic Properties of Reinforcing Steel under High Strain Rates
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1056 Failure Modes of Blast-Loaded Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10561 Global Structural Behavior
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10562 Localized Structural Behavior
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10563 PressurendashImpulse ( PndashI ) Diagrams
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1057 Blast WavendashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1058 Effect of Ground Shocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10581 Loads from Air-Induced Ground Shock
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10582 Loads from Direct Ground Shock
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1059 Technical Design Manuals for Blast-Resistant Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 10510 Computer Programs for Blast and Shock Effects
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 106 Impact Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1061 Structural Impact between Two Bodies mdash Hard Impact and Soft Impact
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1062 Example mdash Aircraft Impact
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 107 Floor Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1071 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1072 Types of Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10721 Walking
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10722 Rhythmic Activities
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10723 Mechanical Equipment
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10724 Analysis Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1073 Natural Frequency of Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10731 Computing the Natural Frequency
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10732 Computing Deflection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10733 Damping
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10734 Resonance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1074 Vibration Caused by Walking
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10741 Minimum Natural Frequency
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1075 Design for Rhythmic Excitation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10751 Harmonics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10752 Minimum Natural Frequency
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1076 Example mdash Vibration Analysis of a Reinforced Concrete Floor
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 53191ch11
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Chapter 11 Seismic Base Isolation and Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 111 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1111 From Ductility Design to Base Isolation and Control Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1112 The Importance of Reducing Seismic Input and Response
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 112 Seismic Base Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1121 Historical Development of Base Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1122 Basic Principle
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1123 Issues in Seismic Base Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11231 Performance Criteria
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11232 Type of Structure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11233 Site Characteristics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11234 Retrofit Issues
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11235 Design of Building Services
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11236 Expected Life of Isolator
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1124 Seismic Isolation Devices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11241 Laminated Rubber Bearings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11242 Lead Rubber Bearing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11243 Friction-Based Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11244 Other Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1125 Design of Isolation Devices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11251 High-Damping Rubber Bearing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112511 Stability against Buckling
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112512 Stability against Roll Out
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11252 Lead Rubber Bearings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112521 Design of Lead Plug
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112522 Design of Laminated Rubber Bearing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11253 Design of Friction Pendulum System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1126 Verification of Properties of Isolation Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11261 Tests for Isolation Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 112611 System Characterization Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 112612 Prototype Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 112613 Quality Control Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11262 Uniform Building Code Recommendations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112621 Units Dependent on Loading Rates
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112622 Units Dependent on Bilateral Load
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112623 System Adequacy
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1127 Analysis of Base-Isolated Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11271 Modeling of a Superstructure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11272 Modeling of Isolation System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11273 Static Analysis Procedure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11274 Dynamic Analysis Procedure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 112741 Response Spectrum Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 112742 Time-History Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11275 Software for Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1128 Experimental Methods for Isolated Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1129 Implementation of Seismic Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11291 New Construction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112911 Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112912 Bridges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11292 Seismic Retrofit
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112921 Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112922 Bridges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11293 Other Implementations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 11210 Performance during Past Earthquakes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 112101 Performance of Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 112102 Performance of Bridges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 113 Seismic Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1131 Historical Development of Seismic Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1132 Basic Principles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11321 Passive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11322 Active Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11323 Semiactive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11324 Hybrid Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11325 Categorization of Basic Principles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1133 Important Issues in Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11331 SoilndashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11332 DevicendashStructure Interaction and Time Delay
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11333 Design Guidelines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1134 Vibration-Control Devices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11341 Passive Control Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113411 Metallic Yielding Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113412 Friction Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113413 Viscoelastic Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113414 Viscous Fluid Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113415 Tuned Mass Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11342 Active Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113421 Electromagnetic Actuator
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113422 Hydraulic Actuators
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11343 Semiactive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113431 Variable-Orifice Hydraulic Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113432 Controllable Fluid Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113433 Controllable Friction Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11344 Hybrid Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1135 Control Algorithm
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11351 Active Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11352 Semiactive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113521 Common Control Schemes for Controllable Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113522 Special Control Schemes for Controllable Damper
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1136 Experimental Performance Verification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11361 Shaking Table Tests of a Flexible Structural Model with TMD AMD and ATMD
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11362 Substructure Hybrid Test
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113621 Hybrid Tests Using Hydraulic Actuator
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113622 Hybrid Tests Using Shaking Table
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113623 Hybrid Tests Using Inertia-Force-Driven Loading System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1137 Implementations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11371 Semiactive Control of Full-Scale Structures Using Variable Joint Damper System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113711 Background of Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113712 Test System Set Up
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113713 Control Algorithm
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113714 Test Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11372 Application of Structural Control Technologies to Seismic Retrofit of a Cable-Stayed Bridge
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113721 Background of Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113722 Basic Concept of Seismic Retrofit
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113723 Modal Shape Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113724 Time-History Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113725 Soil ndash Structure Interaction Effect
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113726 Semiactive Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53191ch12
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Chapter 12 Seismic Random Vibration of Long-Span Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 121 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1211 Basic Concepts of Random Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12111 Stationary Random Process
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12112 Nonstationary Random Process
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1212 Three Methods for Structural Seismic Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12121 Response Spectrum Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12122 Time-History Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12123 Random Vibration Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 121231 Davenport Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 121232 Vanmarcke Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 12124 Comparisons of the Three Seismic-Analysis Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 122 Seismic Random-Excitation Fields
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1221 Power Spectral Density of Spatially Varying Ground Acceleration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1222 Several Coherence Models
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12221 FengndashHu Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12222 Harichandran ndashVanmarcke Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12223 LohndashYeh Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12224 OliveirandashHaondashPenzien Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12225 LucondashWong Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12226 QundashWangndashWang Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1223 Generation of Ground Acceleration Power Spectral Density Curves from Acceleration Response Spectrum Curves
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12231 Kaul Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12232 Iteration Scheme
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1224 Seismic Equations of Motion of Long-Span Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1225 Seismic Waves and Their Geometrical Expressions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 123 Pseudoexcitation Method for Structural Random Vibration Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1231 Structures Subjected to Stationary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12311 Single Stationary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12312 Multiple Stationary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1232 Structures Subjected to Nonstationary Random Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12321 Structures Subjected to Uniformly Modulated Evolutionary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 123211 Single Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 123212 Multiple Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12322 Structures Subjected to Nonuniformly Modulated Evolutionary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 123221 Single Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 123222 Multiple Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1233 Precise Integration Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12331 Precise Integration of Exponential Matrices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12332 Particular Solutions and Precise Integration Formulas for Various Forms of Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 123321 Linear Loading Form (HPD-L Form)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 123322 Sinusoidal Loading Form (HPD-S Form)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 123323 Exponentially Decaying Sinusoidal Loading Form (HPD-E Form)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 124 Long-Span Structures Subjected to Stationary Random Ground Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1241 The Solution of Equations of Motion Using the Pseudoexcitation Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1242 Numerical Comparisons with Other Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12421 Song-Hua-Jiang Suspension Bridge
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 124211 All Supports Move Uniformly
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 124212 Wave Passage Effect Is Taken into Account
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 124213 Wave-Passage Effect and Incoherence Effect Are Jointly Taken into Account
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 12422 San Joaquin Concrete Bridge
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 125 Long-Span Structures Subjected to Nonstationary Random Ground Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1251 Modulation Functions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1252 The Formulas for Nonstationary Multiexcitation Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1253 Expected Extreme Values of Nonstationary Random Processes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1254 Numerical Comparisons with the Corresponding Stationary Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 126 Conclusions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 53191ch13
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Chapter 13 Seismic Qualification of Equipment
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 131 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 132 Distribution Qualification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1321 Drive-Signal Generation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1322 Distribution Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1323 Test Procedures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 133 Seismic Qualification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1331 Stages of Seismic Qualification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1332 Test Preliminaries
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1333 Single-Frequency Testing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1334 Multifrequency Testing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1335 Generation of RRS Specifications
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 53191ch14
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Chapter 14 Human Response to Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 141 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 142 Vibration Excitations on Humans
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1421 Excitation Characteristics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 143 Human Response to Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1431 Vibration Perception
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1432 Frequency Weighting Curve
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1433 Iso-Perception Curves
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1434 Detection Threshold Curve
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 144 Regulation of Human Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1441 Acceptable Vibration Levels in Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1442 Whole-Body Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1443 HandndashArm Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
Page 26: Vibration Monitoring, Testing, and Instrumentationpreview.kingborn.net › 646000 › d1a74678d91943e5ba1d5e... · The MEMS Handbook, Second Edition MEMS: Introduction and Fundamentals

frac12mes2 thorn ethbthorn beTHORNsthorn ethkthorn keTHORN ye frac14 ethbsthorn kTHORNy thorn kb

Rev2

k2bs

Reye eth124THORN

It follows that the transfer function of the shaker head motion with respect to the excitation voltage is

given by

yevfrac14 kb

Re

DethsTHORNDdethsTHORN eth125THORN

where DethsTHORN is the characteristic function of the primary dynamics of the test object

DethsTHORN frac14 ms2 thorn bsthorn k eth126THORN

and DdethsTHORN is the characteristic function of the primary dynamic interactions between the shaker and thetest object

DcethsTHORN frac14 mmes4 thorn frac12methbe thorn bthorn boTHORN thornmeb s

3 thorn frac12methke thorn kTHORN thornmekthorn bethbe thorn boTHORN s2thorn frac12bke thorn ethbe thorn boTHORNk sthorn kke

eth127THORN

where

bo frac14 k2bRe

eth128THORN

It is clear that under low damping conditions DdethsTHORN will produce two resonances as it is fourth order in sand similarly DethsTHORN will produce one antiresonance (trough) corresponding to the resonance of the testobject Note that in the frequency domain s frac14 jv and hence the frequency response function given by

Equation 125 is in fact

yevfrac14 kb

Rb

DethjvTHORNDdethjvTHORN eth129THORN

The magnitude of this frequency response function for a typical test system is sketched in Figure 110

Note that this curve is for the ldquoopen-looprdquo case where there is no feedback from the shaker controller

In practice the shaker controller will be able

to compensate for the resonances and anti-

resonances to some degree depending on its

effectiveness

The main advantages of electromagnetic

shakers are their high frequency range of

operation their high degree of operating flexi-

bility and the high level of accuracy of the

generated shaker motion Faithful reproduction

of complex excitations is possible because of the

advanced electronics and control systems used in

this type of shakers Electromagnetic shakers are

not suitable for heavy-duty applications (large test

objects) however High test-input accelerations

are possible at high frequencies when electromag-

netic shakers are used but their displacement and

velocity capabilities are limited to low or

intermediate values (see Table 11)

100

10

1 10 100Excitation Frequency (Hz)

Antiresonance

Resonance

Shak

erD

ispl

acem

entM

agni

tude

Resonance

1000

FIGURE 110 Frequency response curve of a typical

electromagnetic shaker with a test object

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copy 2007 by Taylor amp Francis Group LLC

1221 Transient Exciters

Other varieties of exciters are commonly used in

transient-type vibration testing In these tests

either an impulsive force or an initial excitation is

applied to the test object and the resulting

response is monitored The excitations and the

responses are ldquotransientrdquo in this case Hammer

test drop tests and pluck tests fall into this

category For example a hammer test may be

conducted by hitting the object with an instru-

mented hammer and then measuring the response

of the object The hammer has a force sensor at its

tip as sketched in Figure 111 A piezoelectric or

strain-gage type force sensor may be used More

sophisticated hammers have impedance heads in

place of force sensors An impedance head

measures force and acceleration simultaneously

The results of a hammer test will depend on many

factors for example the dynamics of the hammer

body how firmly the hammer is held during the

impact how quickly the impact is applied and

whether there are multiple impacts

13 Control System

The two primary functions of the shaker control system in vibration testing are (1) to guarantee that the

specified excitation is applied to the test object and (2) to ensure that the dynamic stability (motion

constraints) of the test setup is preserved An operational block diagram illustrating these control

functions is given in Figure 112 The reference input to the control system represents the desired

excitation force that should be applied to the test object In the absence of any control however the force

reaching the test object will be distorted primarily because of (1) dynamic interactions and

nonlinearities of the shaker the test table the mounting fixtures the auxiliary instruments and the test

object itself (2) noise and errors in the signal generator amplifiers filters and other equipment and (3)

external loads and disturbances acting on the test object and other components (for example external

restraints aerodynamic forces friction) To compensate for these distorting factors response

measurements (displacements velocities acceleration and so on) are made at various locations in the

test setup and are used to control the system dynamics In particular the responses of the shaker the test

table and the test object are measured These responses are used to compare the actual excitation felt by

FIGURE 111 An instrumented hammer used in bump

tests or hammer tests

ExcitationInput

(Reference)

Feedback Paths

DriveSignal

ShakerResponse

TestTable

TestObject

Test ObjectResponse

Test TableResponseExciter

(Shaker)(Ram)

Controllerand

Amplifier

FIGURE 112 Operational block diagram illustrating a general shaker control system

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copy 2007 by Taylor amp Francis Group LLC

the test object at the shaker interface with the desired (specified) input The drive signal to the shaker is

modified depending on the error that is present

Two types of control are commonly employed in shaker apparatus simple manual control and

complex automatic control Manual control normally consists of simple open-loop trial-and-error

methods of manual adjustments (or calibration) of the control equipment to obtain a desired dynamic

response The actual response is usually monitored (on an oscilloscope or frequency analyzer screen for

example) during manual-control operations The pretest adjustments in manual control can be very

time-consuming as a result the test object might be subjected to overtesting which could produce

cumulative damage is undesirable and could defeat the test purpose Furthermore the calibration

procedure for the experimental setup must be repeated for each new test object

The disadvantages ofmanual control suggest that automatic control is desirable in complex test schemes

in which high accuracy of testing is desired The first step of automatic control involves automatic

measurement of the system response using control sensors and transducers The measurement is then fed

back into the control system which instantaneously determines the best drive signal to actuate the shaker

in order to get the desired excitation This may be done by either analog or digital methods

Primitive control systems require an accurate mathematical description of the test object This

dependency of the control system on the knowledge of test-object dynamics is clearly undesirable

Performance of a good control system should not be considerably affected by the dynamic interactions

and nonlinearities of the test object or by the nature of the excitation Proper selection of feedback signals

and control-system components can reduce such effects and will make the system robust

In the response-spectrum method of vibration testing it is customary to use displacement control at

low frequencies velocity control at intermediate frequency and acceleration control at high frequencies

This necessitates feedback of displacement velocity and acceleration responses Generally however the

most important feedback is the velocity feedback In sine-sweep tests the shaker velocity must change

steadily over the frequency band of interest In particular the velocity control must be precise near the

resonances of the test object Velocity (speed) feedback has a stabilizing effect on the dynamics which is

desirable This effect is particularly useful in ensuring stability in motion when testing is done near

resonances of lightly damped test objects On the contrary displacement (position) feedback can have a

destabilizing effect on some systems particularly when high feedback gains are used

The controller usually consists of various instruments equipment and computation hardware and

software Often the functions of the data-acquisition and processing system overlap with those of the

controller to some extent As an example consider the digital-controller of vibration testing apparatus

First the responses are measured through sensors (and transducers) filtered and amplified

(conditioned) These data channels may be passed through a multiplexer whose purpose is to select

one data channel at a time for processing Most modern data acquisition hardware does not need a

separate multiplexer to handle multiple signals The analog data are converted into digital data using

analog-to-digital converters (ADCs) The resulting sampled data are stored on a disk or as a block data in

the computer memory The reference input signal (typically a signal recorded on an FM tape) is also

sampled (if it is not already in the digital form) using an ADC and fed into the computer Digital

processing is done on the reference signal and the response data with the objective of computing the

command signal to drive the shaker The digital command signal is converted into an analog signal using

a digital-to-analog converter (DAC) and amplified (conditioned) before it is used to drive the exciter

The nature of the control components depends to a large extent on the nature and objectives of the

particular test to be conducted Some of the basic components in a shaker controller are described in

the following subsections

131 Components of a Shaker Controller

1311 Compressor

A compressor circuit is incorporated in automatic excitation control devices to control the excitation-

input level automatically The level of control depends on the feedback signal from a control sensor and

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copy 2007 by Taylor amp Francis Group LLC

the specified (reference) excitation signal Usually the compressor circuit is included in the excitation-

signal generator (for example in a sine generator) The control by this means may be done on the basis of

a single-frequency component (eg the fundamental frequency)

1312 Equalizer (Spectrum Shaper)

Random-signal equalizers are used to shape the spectrum of a random signal in a desired manner In

essence and equalizer consists of a bank of narrow-band filters (for example 80 filters) in parallel over

the operating frequency range By passing the signal through each filter the spectral density (or the mean

square value) of the signal in that narrow frequency band (for example each one-third-octave band) is

determined This is compared with the desired spectral level and automatic adjustment is made in that

filter in case there is an error In some systems response-spectrum analysis is made in place of power

spectral density analysis In that case the equalizer consists of a bank of simple oscillators whose

resonant frequencies are distributed over the operating frequency range of the equalizer The feedback

signal is passed through each oscillator and the peak value of its output is determined This value is

compared with the desired response spectrum value at that frequency If there is an error automatic gain

adjustment is made in the appropriate excitation signal components

Random-noise equalizers are used in conjunction with random signal generators They receive

feedback signals from the control sensors In some digital control systems there are algorithms (software)

that are used to iteratively converge the spectrum of the excitation signal felt by the test object into the

desired spectrum

1313 Tracking Filter

Many vibration tests are based on single-frequency excitations In such cases the control functions

should be performed on the basis of the amplitudes of the fundamental-frequency component of the

signal A tracking filter is simply a frequency-tuned band-pass filter It automatically tunes the center

frequency of its very narrow-band-pass filter to the frequency of a carrier signal Then when a noisy

signal is passed through the tuned filter the output of the filter will be the required fundamental

frequency component in the signal Tracking filters also are useful in obtaining amplitudendashfrequency

plots using an XndashY plotter In such cases the frequency value comes from the signal generator (sweep

oscillator) which produces the carrier signal to the tracking filter The tracking filter then determines the

corresponding amplitude of a signal that is fed into it Most tracking filters have dual channels so that two

signals can be handled (tracked) simultaneously

1314 Excitation Controller (Amplitude Servo-Monitor)

An excitation controller is typically an integral part of the signal generator It can be set so that automatic

sweep between two frequency limits can be performed at a selected sweep rate (linear or logarithmic)

More advanced excitation controllers have the capability of an automatic switch-over between constant-

displacement constant-velocity and constant-acceleration excitation-input control at specified

frequencies over the sweep frequency interval Consequently integrator circuits should be present

within the excitation controller unit to determine velocities and displacements from acceleration signals

Sometimes integration is performed by a separate unit called a vibration meter This unit also offers

the operator the capability of selecting the desired level of each signal (acceleration velocity or

displacement) There is an automatic cut-off level for large displacement values that could result from

noise in acceleration signals A compressor is also a subcomponent of the excitation controller The

complete unit is sometimes known as an amplitude servo-monitor

132 Signal-Generating Equipment

Shakers are force-generating devices that are operated using drive (excitation) signals generated from a

source The excitation-signal source is known as the signal generator Three major types of signal

generators are used in vibration testing applications (1) oscillators (2) random-signal generators and

(3) storage devices In some units oscillators and random-signal generators are combined We shall

Vibration Instrumentation 1-17

53191mdash522007mdash1202mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

discuss these two generators separately however because of their difference in function It also should be

noted that almost any digital signal (deterministic or random) can be generated by a digital computer

using a suitable computer program the signal eventually can be passed through a DAC to obtain

the corresponding analog signal These lsquodigitalrsquo signal generators along with analog sources such as

magnetic tape players (FM) are classified into the category of storage devices

The dynamic range of equipment is the ratio of the maximum and minimum output levels (expressed

in decibels) at which it is capable of operating without significant error This is an important specification

for many types of equipment particularly for signal-generating devices The output level of the signal

generator should be set to a value within its dynamic range

1321 Oscillators

Oscillators are essentially single-frequency generators Typically sine signals are generated but other

waveforms (such as rectangular and triangular pulses) are also available in most oscillators Normally

an oscillator has two modes of operation (1) sweeping up and down between two frequency limits and

(2) dwelling at a specified frequency In the sweep operation the sweep rate should be specified This can

be done either on a linear scale (Hzmin) or on a logarithmic scale (octavesmin) In the dwell operation

the frequency points (or intervals) should be specified In either case a desired signal level can be chosen

using the gain-control knob An oscillator that is operated exclusively in the sweep mode is called a sweep

oscillator

The early generation of oscillators employed variable inductor-capacitor types of electronic circuits to

generate signals oscillating at a desired frequency The oscillator is tuned to the required frequency by

varying the capacitance or inductance parameters A DC voltage is applied to energize the capacitor

and to obtain the desired oscillating voltage signal which subsequently is amplified and conditioned

Modern oscillators use operational amplifier circuits along with resistor capacitor and semiconductor

(SC) elements Also common are crystal (quartz) parallel-resonance oscillators used to generate voltage

signals accurately at a fixed frequency The circuit is activated using a DC-voltage source Other

frequencies of interest are obtained by passing this high-frequency signal through a frequency converter

The signal is then conditioned (amplified and filtered) Required shaping (for example rectangular

pulse) is obtained using a shape circuit Finally the required signal level is obtained by passing the

resulting signal through a variable-gain amplifier A block diagram of an oscillator illustrating various

stages in the generation of a periodic signal is given in Figure 113

A typical oscillator offers a choice of several (typically six) linear and logarithmic frequency ranges and

a sizable level of control capability (for example 80 dB) Upper and lower frequency limits in a sweep can

be preset on the front panel to any of the available frequency ranges Sweep-rate settings are continuously

DC Voltage

Oscillator

FrequencySpecification

FrequencyConverter

FilterAmplifier

ShaperPeriodicSignal

FrequencyCounter

Fixed-FrequencySignal

Variable-GainOutput

Amplifier

SignalSpecification

LevelSpecification

FIGURE 113 Block diagram of an oscillator-type signal generator

Vibration Monitoring Testing and Instrumentation1-18

53191mdash522007mdash1202mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

  • 53191fm
    • Vibration Monitoring Testing and Instrumentation
      • Preface
      • Acknowledgments
      • Editor-in-Chief
      • Contributors
      • Contents
      • Related Titles
          • 53191ch1
            • Table of Contents
            • Chapter 1 Vibration Instrumentation
              • Summary
              • 11 Introduction
              • 12 Vibration Exciters
                • 121 Shaker Selection
                  • 1211 Force Rating
                  • 1212 Power Rating
                  • 1213 Stroke Rating
                  • 1214 Hydraulic Shakers
                  • 1215 Inertial Shakers
                  • 1216 Electromagnetic Shakers
                    • 122 Dynamics of Electromagnetic Shakers
                      • 1221 Transient Exciters
                          • 13 Control System
                            • 131 Components of a Shaker Controller
                              • 1311 Compressor
                              • 1312 Equalizer (Spectrum Shaper)
                              • 1313 Tracking Filter
                              • 1314 Excitation Controller (Amplitude Servo-Monitor)
                                • 132 Signal-Generating Equipment
                                  • 1321 Oscillators
                                  • 1322 Random Signal Generators
                                  • 1323 Tape Players
                                  • 1324 Data Processing
                                      • 14 Performance Specification
                                        • 141 Parameters for Performance Specification
                                          • 1411 Time-Domain Specifications
                                          • 1412 Frequency-Domain Specifications
                                            • 142 Linearity
                                            • 143 Instrument Ratings
                                              • 1431 Rating Parameters
                                                • 144 Accuracy and Precision
                                                  • 15 Motion Sensors and Transducers
                                                    • 151 Potentiometer
                                                      • 1511 Potentiometer Resolution
                                                      • 1512 Optical Potentiometer
                                                        • 152 Variable-Inductance Transducers
                                                          • 1521 Mutual-Induction Transducers
                                                          • 1522 Linear-Variable Differential Transformer
                                                          • 1523 Signal Conditioning
                                                            • 153 Mutual-Induction Proximity Sensor
                                                            • 154 Selfinduction Transducers
                                                            • 155 Permanent-Magnet Transducers
                                                            • 156 Alternating Current Permanent-Magnet Tachometer
                                                            • 157 Alternating Current Induction Tachometer
                                                            • 158 Eddy Current Transducers
                                                            • 159 Variable-Capacitance Transducers
                                                              • 1591 Capacitive Displacement Sensors
                                                              • 1592 Capacitive Angular Velocity Sensor
                                                              • 1593 Capacitance Bridge Circuit
                                                                • 1510 Piezoelectric Transducers
                                                                  • 15101 Sensitivity
                                                                  • 15102 Piezoelectric Accelerometer
                                                                  • 15103 Charge Amplifier
                                                                      • 16 Torque Force and Other Sensors
                                                                        • 161 Strain Gage Sensors
                                                                          • 1611 Equations for Strain Gage Measurements
                                                                          • 1612 Bridge Sensitivity
                                                                          • 1613 The Bridge Constant
                                                                          • 1614 The Calibration Constant
                                                                          • 1615 Data Acquisition
                                                                          • 1616 Accuracy Considerations
                                                                          • 1617 Semiconductor Strain Gages
                                                                          • 1618 Force and Torque Sensors
                                                                          • 1619 Strain Gage Torque Sensors
                                                                          • 16110 Deflection Torque Sensors
                                                                          • 16111 Variable-Reluctance Torque Sensor
                                                                          • 16112 Reaction Torque Sensors
                                                                            • 162 Miscellaneous Sensors
                                                                              • 1621 Stroboscope
                                                                              • 1622 Fiber Optic Sensors and Lasers
                                                                              • 1623 Fiber-Optic Gyroscope
                                                                              • 1624 Laser Doppler Interferometer
                                                                              • 1625 Ultrasonic Sensors
                                                                              • 1626 Gyroscopic Sensors
                                                                                  • References
                                                                                  • Appendix 1A Virtual Instrumentation for Data Acquisition Analysis and Presentation
                                                                                    • Summary
                                                                                    • List of Abbreviations
                                                                                    • 1A1 Dynamic Signals
                                                                                      • 1A11 Acquiring and Simulating Dynamic Signals
                                                                                        • 1A111 Aliasing
                                                                                        • 1A112 Time Continuity
                                                                                            • 1A2 Measurement Configuration Considerations
                                                                                              • 1A21 Input Signal Considerations
                                                                                                • 1A211 Input Pseudodifferential and Differential Configuration
                                                                                                • 1A212 Gain
                                                                                                • 1A213 Input Coupling
                                                                                                • 1A214 Integrated Electronic Piezoelectric Excitation
                                                                                                • 1A215 Nyquist Frequency and Bandwidth
                                                                                                • 1A216 Analog-to-Digital Conversion
                                                                                                • 1A217 Antialias Filters
                                                                                                • 1A218 Input Filter Delay
                                                                                                • 1A219 Overload Detection
                                                                                                  • 1A22 Output Signal Considerations
                                                                                                    • 1A221 Output Pseudodifferential and Differential Configuration
                                                                                                    • 1A222 Attenuation
                                                                                                    • 1A223 Digital-to-Analog Conversion
                                                                                                    • 1A224 Anti-imaging and Interpolation Filters
                                                                                                    • 1A225 Output Filter Delay
                                                                                                        • 1A3 Scaling and Calibration
                                                                                                          • 1A31 Scaling to Engineering Units
                                                                                                          • 1A32 Performing System Calibration
                                                                                                            • 1A321 Propagation Delay Calibration
                                                                                                                • 1A4 Limit Testing Analysis
                                                                                                                  • 1A41 Limit Testing Overview
                                                                                                                  • 1A42 Using the SVT Limit Testing VI
                                                                                                                    • 1A5 Integration
                                                                                                                      • 1A51 Introduction to Integration
                                                                                                                      • 1A52 Implementing Integration
                                                                                                                        • 1A521 Challenges when Integrating Vibration Data
                                                                                                                          • 1A53 Time-Domain Integration
                                                                                                                            • 1A531 Single-Shot Acquisition and Integration
                                                                                                                            • 1A532 Continuous Acquisition and Integration
                                                                                                                              • 1A54 Frequency-Domain Integration
                                                                                                                                • 1A6 Vibration-Level Measurements
                                                                                                                                  • 1A61 Measuring the Root Mean Square Level
                                                                                                                                    • 1A611 Single-Shot Buffered Acquisition
                                                                                                                                    • 1A612 Continuous Signal Acquisition
                                                                                                                                      • 1A62 Performing a Running RMS Level Measurement
                                                                                                                                      • 1A63 Computing the Peak Level
                                                                                                                                      • 1A64 Computing the Crest Factor
                                                                                                                                        • 1A7 Frequency Analysis
                                                                                                                                          • 1A71 FFT Fundamentals
                                                                                                                                            • 1A711 Number of Samples
                                                                                                                                            • 1A712 Frequency Resolution
                                                                                                                                            • 1A713 Maximum Resolvable Frequency
                                                                                                                                            • 1A714 Minimum Resolvable Frequency
                                                                                                                                            • 1A715 Number of Spectral Lines
                                                                                                                                            • 1A716 Relationship between Time-Domain and Frequency-Domain Specifications and Parameters
                                                                                                                                              • 1A72 Increasing Frequency Resolution
                                                                                                                                                • 1A721 Zoom FFT Analysis
                                                                                                                                                • 1A722 Frequency Resolution of the Zoom FFT VIs
                                                                                                                                                • 1A723 Zoom Measurement
                                                                                                                                                • 1A724 Zoom Settings
                                                                                                                                                • 1A725 Subset Analysis
                                                                                                                                                    • 1A8 Transient Analysis
                                                                                                                                                      • 1A81 Transient Analysis with the Sound and Vibration Toolkit
                                                                                                                                                      • 1A82 Performing an STFT vs Time
                                                                                                                                                        • 1A821 Selecting the FFT Block Size
                                                                                                                                                        • 1A822 Overlapping
                                                                                                                                                        • 1A823 Using the SVT STFT vs Time VI
                                                                                                                                                          • 1A83 Performing an STFT vs Rotational Speed
                                                                                                                                                            • 1A831 Converting the Pulse Train to Rotational Speed
                                                                                                                                                            • 1A832 STFT vs RPM
                                                                                                                                                              • 1A84 Measuring a Shock Response Spectrum
                                                                                                                                                                • 1A9 Waterfall Display
                                                                                                                                                                  • 1A91 Using the Display VIs
                                                                                                                                                                    • 1A911 Initializing the Display
                                                                                                                                                                    • 1A912 Sending Data to the Display
                                                                                                                                                                    • 1A913 Waterfall Display for Frequency Analysis
                                                                                                                                                                    • 1A914 Waterfall Display for Transient Analysis
                                                                                                                                                                    • 1A915 Waterfall Display for Octave Spectra
                                                                                                                                                                        • 1A10 Swept-Sine Measurements
                                                                                                                                                                          • 1A101 Swept-Sine Overview
                                                                                                                                                                          • 1A102 Choosing Swept-Sine vs FFT Measurements
                                                                                                                                                                          • 1A103 Taking a Swept-Sine Measurement
                                                                                                                                                                          • 1A104 Swept-Sine Measurement Example
                                                                                                                                                                              • Bibliography
                                                                                                                                                                              • Related Titles
                                                                                                                                                                                  • 53191ch2
                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                    • Chapter 2 Signal Conditioning and Modification
                                                                                                                                                                                      • Summary
                                                                                                                                                                                      • 21 Introduction
                                                                                                                                                                                      • 22 Amplifiers
                                                                                                                                                                                        • 221 Operational Amplifier
                                                                                                                                                                                        • 222 Use of Feedback in Opamp
                                                                                                                                                                                        • 223 Voltage Current and Power Amplifiers
                                                                                                                                                                                          • 2231 Charge Amplifiers
                                                                                                                                                                                            • 224 Instrumentation Amplifiers
                                                                                                                                                                                              • 2241 Differential Amplifier
                                                                                                                                                                                              • 2242 Common Mode
                                                                                                                                                                                                • 225 Amplifier Performance Ratings
                                                                                                                                                                                                  • 2251 Common-Mode Rejection Ratio
                                                                                                                                                                                                    • 226 Component Interconnection
                                                                                                                                                                                                      • 2261 Impedance Characteristics
                                                                                                                                                                                                      • 2262 Cascade Connection of Devices
                                                                                                                                                                                                      • 2263 AC-Coupled Ampliers
                                                                                                                                                                                                          • 23 Analog Filters
                                                                                                                                                                                                            • 231 Passive Filters and Active Filters
                                                                                                                                                                                                              • 2311 Number of Poles
                                                                                                                                                                                                                • 232 Low-Pass Filters
                                                                                                                                                                                                                  • 2321 Low-Pass Butterworth Filter
                                                                                                                                                                                                                    • 233 High-Pass Filters
                                                                                                                                                                                                                    • 234 Band-Pass Filters
                                                                                                                                                                                                                      • 2341 Resonance-Type Band-Pass Filters
                                                                                                                                                                                                                        • 235 Band-Reject Filters
                                                                                                                                                                                                                          • 24 Modulators and Demodulators
                                                                                                                                                                                                                            • 241 Amplitude Modulation
                                                                                                                                                                                                                              • 2411 Modulation Theorem
                                                                                                                                                                                                                              • 2412 Side Frequencies and Side Bands
                                                                                                                                                                                                                                • 242 Application of Amplitude Modulation
                                                                                                                                                                                                                                  • 2421 Fault Detection and Diagnosis
                                                                                                                                                                                                                                    • 243 Demodulation
                                                                                                                                                                                                                                      • 25 Analog ndashDigital Conversion
                                                                                                                                                                                                                                        • 251 Digital-to-Analog Conversion
                                                                                                                                                                                                                                          • 2511 DAC Error Sources
                                                                                                                                                                                                                                            • 252 Analog-to-Digital Conversion
                                                                                                                                                                                                                                            • 253 Analog-to-Digital Converter Performance Characteristics
                                                                                                                                                                                                                                              • 2531 Resolution and Quantization Error
                                                                                                                                                                                                                                              • 2532 Monotonicity Nonlinearity and Offset Error
                                                                                                                                                                                                                                              • 2533 Analog-to-Digital Converter Conversion Rate
                                                                                                                                                                                                                                                • 254 Sample-and-Hold Circuitry
                                                                                                                                                                                                                                                • 255 Digital Filters
                                                                                                                                                                                                                                                  • 2551 Software Implementation and Hardware Implementation
                                                                                                                                                                                                                                                      • 26 Bridge Circuits
                                                                                                                                                                                                                                                        • 261 Wheatstone Bridge
                                                                                                                                                                                                                                                        • 262 Constant-Current Bridge
                                                                                                                                                                                                                                                        • 263 Bridge Amplifiers
                                                                                                                                                                                                                                                          • 2631 Half-Bridge Circuits
                                                                                                                                                                                                                                                            • 264 Impedance Bridges
                                                                                                                                                                                                                                                              • 2641 Owen Bridge
                                                                                                                                                                                                                                                              • 2642 Wien-Bridge Oscillator
                                                                                                                                                                                                                                                                  • 27 Linearizing Devices
                                                                                                                                                                                                                                                                    • 271 Linearization by Software
                                                                                                                                                                                                                                                                    • 272 Linearization by Hardware Logic
                                                                                                                                                                                                                                                                    • 273 Analog Linearizing Circuitry
                                                                                                                                                                                                                                                                    • 274 Offsetting Circuitry
                                                                                                                                                                                                                                                                    • 275 Proportional-Output Circuitry
                                                                                                                                                                                                                                                                      • 2751 Curve-Shaping Circuitry
                                                                                                                                                                                                                                                                          • 28 Miscellaneous Signal Modification Circuitry
                                                                                                                                                                                                                                                                            • 281 Phase Shifters
                                                                                                                                                                                                                                                                            • 282 Voltage-to-Frequency Converter
                                                                                                                                                                                                                                                                            • 283 Frequency-to-Voltage Converter
                                                                                                                                                                                                                                                                            • 284 Voltage-to-Current Converters
                                                                                                                                                                                                                                                                            • 285 Peak-Hold Circuits
                                                                                                                                                                                                                                                                              • 29 Signal Analyzers and Display Devices
                                                                                                                                                                                                                                                                                • 291 Signal Analyzers
                                                                                                                                                                                                                                                                                • 292 Oscilloscopes
                                                                                                                                                                                                                                                                                  • 2921 Triggering
                                                                                                                                                                                                                                                                                  • 2922 Lissajous Patterns
                                                                                                                                                                                                                                                                                  • 2923 Digital Oscilloscopes
                                                                                                                                                                                                                                                                                      • Bibliography
                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                          • 53191ch3
                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                            • Chapter 3 Vibration Testing
                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                              • 31 Introduction
                                                                                                                                                                                                                                                                                              • 32 Representation of a Vibration Environment
                                                                                                                                                                                                                                                                                                • 321 Test Signals
                                                                                                                                                                                                                                                                                                  • 3211 Stochastic vs Deterministic Signals
                                                                                                                                                                                                                                                                                                    • 322 Deterministic Signal Representation
                                                                                                                                                                                                                                                                                                      • 3221 Single-Frequency Signals
                                                                                                                                                                                                                                                                                                      • 3222 Sine Sweep
                                                                                                                                                                                                                                                                                                      • 3223 Sine Dwell
                                                                                                                                                                                                                                                                                                      • 3224 Decaying Sine
                                                                                                                                                                                                                                                                                                      • 3225 Sine Beat
                                                                                                                                                                                                                                                                                                      • 3226 Sine Beat with Pauses
                                                                                                                                                                                                                                                                                                      • 3227 Multifrequency Signals
                                                                                                                                                                                                                                                                                                      • 3228 Actual Excitation Records
                                                                                                                                                                                                                                                                                                      • 3229 Simulated Excitation Signals
                                                                                                                                                                                                                                                                                                        • 323 Stochastic Signal Representation
                                                                                                                                                                                                                                                                                                          • 3231 Ergodic Random Signals
                                                                                                                                                                                                                                                                                                          • 3232 Stationary Random Signals
                                                                                                                                                                                                                                                                                                          • 3233 Independent and Uncorrelated Signals
                                                                                                                                                                                                                                                                                                          • 3234 Transmission of Random Excitations
                                                                                                                                                                                                                                                                                                            • 324 Frequency-Domain Representations
                                                                                                                                                                                                                                                                                                              • 3241 Fourier Spectrum Method
                                                                                                                                                                                                                                                                                                              • 3242 Power Spectral Density Method
                                                                                                                                                                                                                                                                                                                • 325 Response Spectrum
                                                                                                                                                                                                                                                                                                                  • 3251 Displacement Velocity and Acceleration Spectra
                                                                                                                                                                                                                                                                                                                  • 3252 Response-Spectra Plotting Paper
                                                                                                                                                                                                                                                                                                                  • 3253 Zero-Period Acceleration
                                                                                                                                                                                                                                                                                                                  • 3254 Uses of Response Spectra
                                                                                                                                                                                                                                                                                                                    • 326 Comparison of Various Representations
                                                                                                                                                                                                                                                                                                                      • 33 Pretest Procedures
                                                                                                                                                                                                                                                                                                                        • 331 Purpose of Testing
                                                                                                                                                                                                                                                                                                                        • 332 Service Functions
                                                                                                                                                                                                                                                                                                                          • 3321 Active Equipment
                                                                                                                                                                                                                                                                                                                          • 3322 Passive Equipment
                                                                                                                                                                                                                                                                                                                          • 3323 Functional Testing
                                                                                                                                                                                                                                                                                                                            • 333 Information Acquisition
                                                                                                                                                                                                                                                                                                                              • 3331 Interface Details
                                                                                                                                                                                                                                                                                                                              • 3332 Effect of Neglecting Interface Dynamics
                                                                                                                                                                                                                                                                                                                              • 3333 Effects of Damping
                                                                                                                                                                                                                                                                                                                              • 3334 Effects of Inertia
                                                                                                                                                                                                                                                                                                                              • 3335 Effect of Natural Frequency
                                                                                                                                                                                                                                                                                                                              • 3336 Effect of Excitation Frequency
                                                                                                                                                                                                                                                                                                                              • 3337 Other Effects of Interface
                                                                                                                                                                                                                                                                                                                                • 334 Test-Program Planning
                                                                                                                                                                                                                                                                                                                                  • 3341 Testing of Cabinet-Mounted Equipment
                                                                                                                                                                                                                                                                                                                                    • 335 Pretest Inspection
                                                                                                                                                                                                                                                                                                                                      • 34 Testing Procedures
                                                                                                                                                                                                                                                                                                                                        • 341 Resonance Search
                                                                                                                                                                                                                                                                                                                                        • 342 Methods of Determining Frequency-Response Functions
                                                                                                                                                                                                                                                                                                                                          • 3421 Fourier Transform Method
                                                                                                                                                                                                                                                                                                                                          • 3422 Spectral Density Method
                                                                                                                                                                                                                                                                                                                                          • 3423 Harmonic Excitation Method
                                                                                                                                                                                                                                                                                                                                            • 343 Resonance-Search Test Methods
                                                                                                                                                                                                                                                                                                                                              • 3431 Hammer (Bump) Test and Drop Test
                                                                                                                                                                                                                                                                                                                                              • 3432 Pluck Test
                                                                                                                                                                                                                                                                                                                                              • 3433 Shaker Tests
                                                                                                                                                                                                                                                                                                                                                • 344 Mechanical Aging
                                                                                                                                                                                                                                                                                                                                                  • 3441 Equivalence for Mechanical Aging
                                                                                                                                                                                                                                                                                                                                                  • 3442 Excitation-Intensity Equivalence
                                                                                                                                                                                                                                                                                                                                                  • 3443 Dynamic-Excitation Equivalence
                                                                                                                                                                                                                                                                                                                                                  • 3444 Cumulative Damage Theory
                                                                                                                                                                                                                                                                                                                                                    • 345 Test-Response Spectrum Generation
                                                                                                                                                                                                                                                                                                                                                    • 346 Instrument Calibration
                                                                                                                                                                                                                                                                                                                                                    • 347 Test-Object Mounting
                                                                                                                                                                                                                                                                                                                                                    • 348 Test-Input Considerations
                                                                                                                                                                                                                                                                                                                                                      • 3481 Test Nomenclature
                                                                                                                                                                                                                                                                                                                                                      • 3482 Testing with Uncorrelated Excitations
                                                                                                                                                                                                                                                                                                                                                      • 3483 Symmetrical Rectilinear Testing
                                                                                                                                                                                                                                                                                                                                                      • 3484 Geometry vs Dynamics
                                                                                                                                                                                                                                                                                                                                                      • 3485 Some Limitations
                                                                                                                                                                                                                                                                                                                                                      • 3486 Testing Black Boxes
                                                                                                                                                                                                                                                                                                                                                      • 3487 Phasing of Excitations
                                                                                                                                                                                                                                                                                                                                                      • 3488 Testing a Gray or White Box
                                                                                                                                                                                                                                                                                                                                                      • 3489 Overtesting in Multitest Sequences
                                                                                                                                                                                                                                                                                                                                                          • 35 Some Practical Information
                                                                                                                                                                                                                                                                                                                                                            • 351 Random Vibration Test Example
                                                                                                                                                                                                                                                                                                                                                            • 352 Vibration Shakers and Control Systems
                                                                                                                                                                                                                                                                                                                                                              • Bibliography
                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                  • 53191ch4
                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                    • Chapter 4 Experimental Modal Analysis
                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                      • 41 Introduction
                                                                                                                                                                                                                                                                                                                                                                      • 42 Frequency-Domain Formulation
                                                                                                                                                                                                                                                                                                                                                                        • 421 Transfer-Function Matrix
                                                                                                                                                                                                                                                                                                                                                                        • 422 Principle of Reciprocity
                                                                                                                                                                                                                                                                                                                                                                          • 43 Experimental Model Development
                                                                                                                                                                                                                                                                                                                                                                            • 431 Extraction of the Time-Domain Model
                                                                                                                                                                                                                                                                                                                                                                              • 44 Curve Fitting of Transfer Functions
                                                                                                                                                                                                                                                                                                                                                                                • 441 Problem Identification
                                                                                                                                                                                                                                                                                                                                                                                • 442 Single- and Multi-Degree-of-Freedom Techniques
                                                                                                                                                                                                                                                                                                                                                                                • 443 Single-Degree-of-Freedom Parameter Extraction in the Frequency Domain
                                                                                                                                                                                                                                                                                                                                                                                  • 4431 Circle-Fit Method
                                                                                                                                                                                                                                                                                                                                                                                    • Case of Viscous Damping
                                                                                                                                                                                                                                                                                                                                                                                    • Case of Hysteretic Damping
                                                                                                                                                                                                                                                                                                                                                                                      • 4432 Peak-Picking Method
                                                                                                                                                                                                                                                                                                                                                                                        • 444 Multi-Degree of Freedom Curve Fitting
                                                                                                                                                                                                                                                                                                                                                                                          • 4441 Formulation of the Method
                                                                                                                                                                                                                                                                                                                                                                                            • 445 A Comment on Static Modes and Rigid-Body Modes
                                                                                                                                                                                                                                                                                                                                                                                            • 446 Residue Extraction
                                                                                                                                                                                                                                                                                                                                                                                              • 45 Laboratory Experiments
                                                                                                                                                                                                                                                                                                                                                                                                • 451 Lumped-Parameter System
                                                                                                                                                                                                                                                                                                                                                                                                  • 4511 Frequency-Domain Test
                                                                                                                                                                                                                                                                                                                                                                                                  • 4512 Time-Domain Tests
                                                                                                                                                                                                                                                                                                                                                                                                    • 452 Distributed-Parameter System
                                                                                                                                                                                                                                                                                                                                                                                                      • 46 Commercial EMA Systems
                                                                                                                                                                                                                                                                                                                                                                                                        • 461 System Configuration
                                                                                                                                                                                                                                                                                                                                                                                                          • 4611 FFT Analysis Options
                                                                                                                                                                                                                                                                                                                                                                                                          • 4612 Modal Analysis Components
                                                                                                                                                                                                                                                                                                                                                                                                              • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                  • 53191ch5
                                                                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                    • Chapter 5 Mechanical Shock
                                                                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                      • 51 Definitions
                                                                                                                                                                                                                                                                                                                                                                                                                        • 511 Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 512 Simple (or Perfect) Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 513 Half-Sine Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 514 Versed-Sine (or Haversine) Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 515 Terminal Peak Sawtooth Shock or Final Peak Sawtooth Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 516 Rectangular Shock
                                                                                                                                                                                                                                                                                                                                                                                                                          • 5161 Trapezoidal Shock
                                                                                                                                                                                                                                                                                                                                                                                                                              • 52 Description in the Time Domain
                                                                                                                                                                                                                                                                                                                                                                                                                              • 53 Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                • 531 Need
                                                                                                                                                                                                                                                                                                                                                                                                                                • 532 Shock Response Spectrum Definition
                                                                                                                                                                                                                                                                                                                                                                                                                                • 533 Response of a Linear One-Degree-of-Freedom System
                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5331 Shock Defined by a Force
                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5332 Shock Defined by an Acceleration
                                                                                                                                                                                                                                                                                                                                                                                                                                    • 534 Definitions
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5341 Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5342 Absolute Acceleration Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5343 Relative Displacement Shock Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5344 Primary Positive Shock Response Spectrum or Initial Positive Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5345 Primary (or Initial) Negative Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5346 Secondary (or Residual) Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5347 Positive (or Maximum Positive) Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5348 Negative (or Maximum Negative) Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5349 Maximax Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53410 Choice of Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                        • 535 Standardized Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5351 Definition
                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5352 Standardized Shock Response Spectra of Simple Shocks
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53521 Half-Sine Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53522 Versed Sine Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53523 Terminal Peak Sawtooth Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53524 Rectangular Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53525 Trapezoidal Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 536 Choice of Damping
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 537 Shock Response Spectra Domains
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 538 Algorithms for Calculation of the Shock Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 539 Choice of the Digitization Frequency of the Signal
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5310 Use of Shock Response Spectra for the Study of Systems with Several Degrees of Freedom
                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 54 Pyroshocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 55 Use of Shock Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 551 Severity Comparison of Several Shocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 552 Test Specification Development from Real Environment Data
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5521 Synthesis of Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5522 Nature of the Specification
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5523 Choice of Shape
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5524 Amplitude
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5525 Duration
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5526 Difficulties
                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 56 Standards
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 561 Types of Standards
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 562 Installation Conditions of Test Item
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 563 Uncertainty Factor
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 564 Bump Test
                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 57 Damage Boundary Curve
                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 571 Definition
                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 572 Analysis of Test Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 58 Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 581 Main Types
                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 582 Impact Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5821 Universal Shock-Test Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 58211 Impact Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 58212 Impulse Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 583 Shock Simulators (Programmers)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5831 Half-Sine Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58311 Shock Duration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58312 Impact Velocity
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58313 Maximum Deformation of the Shock Simulator (Programmer)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58314 Shock Amplitude
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58315 Characteristics of the Target
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5832 Terminal Peak Sawtooth Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5833 Rectangular Pulse ndash Trapezoidal Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5834 Universal Shock Simulator (Programmer)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 58341 Generating a Half-Sine Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 58342 Generating a Terminal Peak Sawtooth Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 58343 Trapezoidal Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 584 Limitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5841 Limitations of the Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5842 Limitations of Shock Simulators
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 585 Pneumatic Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 586 High Impact Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5861 Lightweight High Impact Shock Machine
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5862 Medium Weight High Impact Shock Machine
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 587 Specific Test Facilities
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 59 Generation of Shock Using Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 591 Principle Behind the Generation of a Simple Shape Signal versus Time
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 592 Main Advantages
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 593 Pre- and Postshocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5931 Requirements
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5932 Solutions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 59321 Optimized Pre- and Postpulses
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5933 Incidence on the Shock Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 594 Limitations of Electrodynamic Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5941 Mechanical Limitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 59411 Abacuses
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5942 Electronic Limitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 595 The Use of Electrohydraulic Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 510 Control by a Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 5101 Principle
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 5102 Principal Shapes of Elementary Signals
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 51021 Decaying Sinusoid
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 51022 ZERD Function
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 51023 WAVSIN Waveform
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 5103 Comparison of WAVSIN SHOC Waveforms and Decaying Sinusoid
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 5104 Criticism of Control by a Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 511 Pyrotechnic Shock Simulation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5111 Simulation Using Pyrotechnic Facilities
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5112 Simulation Using Metal-to-Metal Impact
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5113 Simulation Using Electrodynamic Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5114 Simulation Using Conventional Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53191ch6
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Chapter 6 Machine Condition Monitoring and Fault Diagnostics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 61 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 62 Machinery Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 621 Causes of Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 622 Types of Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 623 Frequency of Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 63 Basic Maintenance Strategies
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 631 Run-to-Failure (Breakdown) Maintenance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 632 Scheduled (Preventative) Maintenance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 633 Condition-Based (Predictive Proactive Reliability Centered On-Condition) Maintenance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 64 Factors Which Influence Maintenance Strategy
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 65 Machine Condition Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 651 Periodic Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 652 Continuous Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 66 Transducer Selection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 661 Noncontact Displacement Transducers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 662 Velocity Transducers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 663 Acceleration Transducers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 67 Transducer Location
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 68 Recording and Analysis Instrumentation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 681 Vibration Meters
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 682 Data Collectors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 683 Frequency-Domain Analyzers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 684 Time-Domain Instruments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 685 Tracking Analyzers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 69 Display Formats and Analysis Tools
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 691 Time Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6911 Time-Waveform Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6912 Time-Waveform Indices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6913 Time-Synchronous Averaging
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6914 Negative Averaging
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6915 Orbits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6916 Probability Density Functions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6917 Probability Density Moments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 692 Frequency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6921 Band-Pass Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6922 Shock Pulse (Spike Energy)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6923 Enveloped Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6924 Signature Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6925 Cascades (Waterfall Plots)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6926 Masks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6927 Frequency-Domain Indices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 693 Modal Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 694 Quefrency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 610 Fault Detection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 6101 Standards
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61011 Standards Based on Machinery Type
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61012 Standards Based on Vibration Severity
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 6102 Acceptance Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 61021 Statistical Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 6103 Frequency-Domain Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61031 Limited Band Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61032 Constant Bandwidth Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61033 Constant Percentage Bandwidth Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 611 Fault Diagnostics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 6111 Forcing Functions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61111 Unbalance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61112 Misalignment
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61113 Mechanical Looseness
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61114 Soft Foot
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61115 Rubs
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61116 Resonances
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61117 Oil Whirl
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61118 Oil Whip
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61119 Structural Vibrations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 611110 Foundation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 6112 Specific Machine Components
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 61121 Damaged or Worn Rolling-Element Bearings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 61122 Damaged or Worn Gears
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 6113 Specific Machine Types
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61131 Pumps
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61132 Fans
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61133 Electric Motors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61134 Steam and Gas Turbines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61135 Compressors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61136 Reciprocating Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 6114 Advanced Fault Diagnostic Techniques
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 53191ch7
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • Chapter 7 Vibration-Based Tool Condition Monitoring Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 71 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 72 Mechanics of Turning
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 721 General Terms
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 722 Chatter Vibrations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 723 Tool Wear
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7231 Tool Failure Mechanisms
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7232 Tool Failure Modes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7233 Tool Wear Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7234 Tool Wear Stages
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 73 Vibration Signal Recording
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 731 Direct and Indirect Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 732 Sensor Requirements for Tool Wear Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 733 Force Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7331 Direct Measurement Dynamometers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7332 Indirect Force Sensors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7333 Piezoelectric Strain Sensors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7334 Resistance Strain Gauges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7335 Customized Force Sensors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 734 Acceleration Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 735 Acoustic Emission Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 736 Sensor Comparisons
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 74 Signal Processing for Sensor-Based Tool Condition Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 741 Feature Extraction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7411 Time Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7412 Frequency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7413 Statistical Processing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7414 TimendashFrequency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 742 Feature Selection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 75 Wear ModelDecision-Making for Sensor-Based Tool Condition Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 751 Trending Threshold
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 752 Neural Networks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7521 Unsupervised Networks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7522 Supervised Networks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 753 Fuzzy Logic
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 754 Other Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 76 Conclusion
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53191ch8
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Chapter 8 Fault Diagnosis of Helicopter Gearboxes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 81 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 82 Abnormality Scaling
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 83 The Structure-Based Connectionist Network
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 84 Sensor Location Selection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 841 Coverage Index
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 842 Overlap Index
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 843 Monitoring Effectiveness
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 85 A Case Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 851 Structural and Featural Influences
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 852 Evaluation of Influences
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 853 Fault Detection Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 854 Fault Diagnostic Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 8541 Faulty Subsystem Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 8542 Faulty Component Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 855 Sensor Location Evaluation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 856 Sensor Location Validation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 86 Conclusion
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 53191ch9
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Chapter 9 Vibration Suppression and Monitoring in Precision Motion Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 91 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 92 Mechanical Design to Minimize Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 921 Stability and Static Determinacy of Machine Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 922 Two-Dimensional Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 923 Three-Dimensional Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 93 Adaptive Notch Filter
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 931 Fast Fourier Transform
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 932 Simulation and Experiments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 94 Real-Time Vibration Analyzer
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 941 Learning Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 942 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 943 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 944 Experiments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 9441 Input Variables mdash the Evaluation Criteria
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 94411 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 94412 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 9442 Evaluation Rules
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 94421 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 94422 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 9443 Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 94431 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 94432 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 95 Practical Insights and Case Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 96 Conclusions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 53191ch10
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Chapter 10 Vibration and Shock Problems of Civil Engineering Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 101 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 102 Earthquake-Induced Vibration of Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1021 Seismicity and Ground Motions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1022 Influence of Local Site Conditions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1023 Response of Structures to Ground Motions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1024 Dynamic Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10241 Equations of Motion for Linear Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10242 Equations of Motion for Linear Multiple-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1025 Earthquake Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10251 Elastic Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10252 Smoothed Design Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10253 Ductility-Modified Response Spectrum Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1026 Design Philosophy and the Code Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10261 Performance-Based Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1027 Analysis Options for Earthquake Effects
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10271 Dynamic Time History Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10272 Response Spectrum Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 102721 Response Spectrum Analysis of Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 102722 Response Spectrum Analysis of Multi-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10273 Equivalent Static Analysis (Force-Based Approach)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10274 Displacement-Based Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1028 SoilndashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1029 Active and Passive Control Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 10210 Worked Examples
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 103 Dynamic Effects of Wind Loading on Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1031 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1032 Wind Speed
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1033 Design Structures for Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10331 Types of Wind Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10332 Design Criteria
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10333 Static Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1034 Along and Across-Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10341 Along-Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10342 Across-Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1035 Wind Tunnel Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1036 Comfort Criteria Human Response to Building Motion
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1037 Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1038 Comparison with Earthquake Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 104 Vibrations Due to Fluid ndashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1041 Added Mass and Inertial Coupling
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1042 Wave-Induced Vibration of Structure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 105 Blast Loading and Blast Effects on Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1051 Explosions and Blast Phenomenon
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1052 Explosive Air-Blast Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10521 Blast Wave Scaling Laws
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10522 Prediction of Blast Pressure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1053 Gas Explosion Loading and Effect of Internal Explosions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1054 Structural Response to Blast Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10541 Elastic Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10542 Elasto-Plastic Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1055 Material Behaviors at High Strain Rate
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10551 Dynamic Properties of Concrete under High Strain Rates
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10552 Dynamic Properties of Reinforcing Steel under High Strain Rates
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1056 Failure Modes of Blast-Loaded Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10561 Global Structural Behavior
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10562 Localized Structural Behavior
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10563 PressurendashImpulse ( PndashI ) Diagrams
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1057 Blast WavendashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1058 Effect of Ground Shocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10581 Loads from Air-Induced Ground Shock
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10582 Loads from Direct Ground Shock
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1059 Technical Design Manuals for Blast-Resistant Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 10510 Computer Programs for Blast and Shock Effects
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 106 Impact Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1061 Structural Impact between Two Bodies mdash Hard Impact and Soft Impact
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1062 Example mdash Aircraft Impact
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 107 Floor Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1071 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1072 Types of Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10721 Walking
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10722 Rhythmic Activities
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10723 Mechanical Equipment
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10724 Analysis Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1073 Natural Frequency of Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10731 Computing the Natural Frequency
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10732 Computing Deflection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10733 Damping
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10734 Resonance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1074 Vibration Caused by Walking
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10741 Minimum Natural Frequency
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1075 Design for Rhythmic Excitation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10751 Harmonics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10752 Minimum Natural Frequency
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1076 Example mdash Vibration Analysis of a Reinforced Concrete Floor
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 53191ch11
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Chapter 11 Seismic Base Isolation and Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 111 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1111 From Ductility Design to Base Isolation and Control Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1112 The Importance of Reducing Seismic Input and Response
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 112 Seismic Base Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1121 Historical Development of Base Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1122 Basic Principle
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1123 Issues in Seismic Base Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11231 Performance Criteria
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11232 Type of Structure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11233 Site Characteristics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11234 Retrofit Issues
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11235 Design of Building Services
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11236 Expected Life of Isolator
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1124 Seismic Isolation Devices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11241 Laminated Rubber Bearings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11242 Lead Rubber Bearing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11243 Friction-Based Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11244 Other Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1125 Design of Isolation Devices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11251 High-Damping Rubber Bearing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112511 Stability against Buckling
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112512 Stability against Roll Out
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11252 Lead Rubber Bearings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112521 Design of Lead Plug
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112522 Design of Laminated Rubber Bearing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11253 Design of Friction Pendulum System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1126 Verification of Properties of Isolation Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11261 Tests for Isolation Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 112611 System Characterization Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 112612 Prototype Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 112613 Quality Control Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11262 Uniform Building Code Recommendations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112621 Units Dependent on Loading Rates
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112622 Units Dependent on Bilateral Load
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112623 System Adequacy
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1127 Analysis of Base-Isolated Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11271 Modeling of a Superstructure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11272 Modeling of Isolation System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11273 Static Analysis Procedure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11274 Dynamic Analysis Procedure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 112741 Response Spectrum Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 112742 Time-History Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11275 Software for Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1128 Experimental Methods for Isolated Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1129 Implementation of Seismic Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11291 New Construction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112911 Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112912 Bridges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11292 Seismic Retrofit
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112921 Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112922 Bridges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11293 Other Implementations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 11210 Performance during Past Earthquakes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 112101 Performance of Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 112102 Performance of Bridges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 113 Seismic Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1131 Historical Development of Seismic Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1132 Basic Principles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11321 Passive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11322 Active Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11323 Semiactive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11324 Hybrid Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11325 Categorization of Basic Principles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1133 Important Issues in Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11331 SoilndashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11332 DevicendashStructure Interaction and Time Delay
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11333 Design Guidelines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1134 Vibration-Control Devices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11341 Passive Control Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113411 Metallic Yielding Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113412 Friction Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113413 Viscoelastic Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113414 Viscous Fluid Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113415 Tuned Mass Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11342 Active Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113421 Electromagnetic Actuator
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113422 Hydraulic Actuators
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11343 Semiactive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113431 Variable-Orifice Hydraulic Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113432 Controllable Fluid Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113433 Controllable Friction Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11344 Hybrid Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1135 Control Algorithm
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11351 Active Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11352 Semiactive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113521 Common Control Schemes for Controllable Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113522 Special Control Schemes for Controllable Damper
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1136 Experimental Performance Verification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11361 Shaking Table Tests of a Flexible Structural Model with TMD AMD and ATMD
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11362 Substructure Hybrid Test
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113621 Hybrid Tests Using Hydraulic Actuator
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113622 Hybrid Tests Using Shaking Table
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113623 Hybrid Tests Using Inertia-Force-Driven Loading System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1137 Implementations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11371 Semiactive Control of Full-Scale Structures Using Variable Joint Damper System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113711 Background of Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113712 Test System Set Up
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113713 Control Algorithm
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113714 Test Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11372 Application of Structural Control Technologies to Seismic Retrofit of a Cable-Stayed Bridge
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113721 Background of Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113722 Basic Concept of Seismic Retrofit
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113723 Modal Shape Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113724 Time-History Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113725 Soil ndash Structure Interaction Effect
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113726 Semiactive Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53191ch12
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Chapter 12 Seismic Random Vibration of Long-Span Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 121 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1211 Basic Concepts of Random Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12111 Stationary Random Process
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12112 Nonstationary Random Process
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1212 Three Methods for Structural Seismic Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12121 Response Spectrum Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12122 Time-History Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12123 Random Vibration Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 121231 Davenport Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 121232 Vanmarcke Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 12124 Comparisons of the Three Seismic-Analysis Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 122 Seismic Random-Excitation Fields
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1221 Power Spectral Density of Spatially Varying Ground Acceleration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1222 Several Coherence Models
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12221 FengndashHu Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12222 Harichandran ndashVanmarcke Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12223 LohndashYeh Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12224 OliveirandashHaondashPenzien Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12225 LucondashWong Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12226 QundashWangndashWang Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1223 Generation of Ground Acceleration Power Spectral Density Curves from Acceleration Response Spectrum Curves
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12231 Kaul Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12232 Iteration Scheme
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1224 Seismic Equations of Motion of Long-Span Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1225 Seismic Waves and Their Geometrical Expressions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 123 Pseudoexcitation Method for Structural Random Vibration Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1231 Structures Subjected to Stationary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12311 Single Stationary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12312 Multiple Stationary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1232 Structures Subjected to Nonstationary Random Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12321 Structures Subjected to Uniformly Modulated Evolutionary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 123211 Single Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 123212 Multiple Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12322 Structures Subjected to Nonuniformly Modulated Evolutionary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 123221 Single Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 123222 Multiple Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1233 Precise Integration Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12331 Precise Integration of Exponential Matrices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12332 Particular Solutions and Precise Integration Formulas for Various Forms of Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 123321 Linear Loading Form (HPD-L Form)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 123322 Sinusoidal Loading Form (HPD-S Form)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 123323 Exponentially Decaying Sinusoidal Loading Form (HPD-E Form)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 124 Long-Span Structures Subjected to Stationary Random Ground Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1241 The Solution of Equations of Motion Using the Pseudoexcitation Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1242 Numerical Comparisons with Other Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12421 Song-Hua-Jiang Suspension Bridge
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 124211 All Supports Move Uniformly
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 124212 Wave Passage Effect Is Taken into Account
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 124213 Wave-Passage Effect and Incoherence Effect Are Jointly Taken into Account
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 12422 San Joaquin Concrete Bridge
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 125 Long-Span Structures Subjected to Nonstationary Random Ground Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1251 Modulation Functions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1252 The Formulas for Nonstationary Multiexcitation Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1253 Expected Extreme Values of Nonstationary Random Processes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1254 Numerical Comparisons with the Corresponding Stationary Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 126 Conclusions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 53191ch13
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Chapter 13 Seismic Qualification of Equipment
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 131 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 132 Distribution Qualification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1321 Drive-Signal Generation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1322 Distribution Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1323 Test Procedures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 133 Seismic Qualification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1331 Stages of Seismic Qualification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1332 Test Preliminaries
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1333 Single-Frequency Testing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1334 Multifrequency Testing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1335 Generation of RRS Specifications
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 53191ch14
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Chapter 14 Human Response to Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 141 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 142 Vibration Excitations on Humans
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1421 Excitation Characteristics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 143 Human Response to Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1431 Vibration Perception
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1432 Frequency Weighting Curve
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1433 Iso-Perception Curves
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1434 Detection Threshold Curve
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 144 Regulation of Human Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1441 Acceptable Vibration Levels in Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1442 Whole-Body Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1443 HandndashArm Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
Page 27: Vibration Monitoring, Testing, and Instrumentationpreview.kingborn.net › 646000 › d1a74678d91943e5ba1d5e... · The MEMS Handbook, Second Edition MEMS: Introduction and Fundamentals

1221 Transient Exciters

Other varieties of exciters are commonly used in

transient-type vibration testing In these tests

either an impulsive force or an initial excitation is

applied to the test object and the resulting

response is monitored The excitations and the

responses are ldquotransientrdquo in this case Hammer

test drop tests and pluck tests fall into this

category For example a hammer test may be

conducted by hitting the object with an instru-

mented hammer and then measuring the response

of the object The hammer has a force sensor at its

tip as sketched in Figure 111 A piezoelectric or

strain-gage type force sensor may be used More

sophisticated hammers have impedance heads in

place of force sensors An impedance head

measures force and acceleration simultaneously

The results of a hammer test will depend on many

factors for example the dynamics of the hammer

body how firmly the hammer is held during the

impact how quickly the impact is applied and

whether there are multiple impacts

13 Control System

The two primary functions of the shaker control system in vibration testing are (1) to guarantee that the

specified excitation is applied to the test object and (2) to ensure that the dynamic stability (motion

constraints) of the test setup is preserved An operational block diagram illustrating these control

functions is given in Figure 112 The reference input to the control system represents the desired

excitation force that should be applied to the test object In the absence of any control however the force

reaching the test object will be distorted primarily because of (1) dynamic interactions and

nonlinearities of the shaker the test table the mounting fixtures the auxiliary instruments and the test

object itself (2) noise and errors in the signal generator amplifiers filters and other equipment and (3)

external loads and disturbances acting on the test object and other components (for example external

restraints aerodynamic forces friction) To compensate for these distorting factors response

measurements (displacements velocities acceleration and so on) are made at various locations in the

test setup and are used to control the system dynamics In particular the responses of the shaker the test

table and the test object are measured These responses are used to compare the actual excitation felt by

FIGURE 111 An instrumented hammer used in bump

tests or hammer tests

ExcitationInput

(Reference)

Feedback Paths

DriveSignal

ShakerResponse

TestTable

TestObject

Test ObjectResponse

Test TableResponseExciter

(Shaker)(Ram)

Controllerand

Amplifier

FIGURE 112 Operational block diagram illustrating a general shaker control system

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the test object at the shaker interface with the desired (specified) input The drive signal to the shaker is

modified depending on the error that is present

Two types of control are commonly employed in shaker apparatus simple manual control and

complex automatic control Manual control normally consists of simple open-loop trial-and-error

methods of manual adjustments (or calibration) of the control equipment to obtain a desired dynamic

response The actual response is usually monitored (on an oscilloscope or frequency analyzer screen for

example) during manual-control operations The pretest adjustments in manual control can be very

time-consuming as a result the test object might be subjected to overtesting which could produce

cumulative damage is undesirable and could defeat the test purpose Furthermore the calibration

procedure for the experimental setup must be repeated for each new test object

The disadvantages ofmanual control suggest that automatic control is desirable in complex test schemes

in which high accuracy of testing is desired The first step of automatic control involves automatic

measurement of the system response using control sensors and transducers The measurement is then fed

back into the control system which instantaneously determines the best drive signal to actuate the shaker

in order to get the desired excitation This may be done by either analog or digital methods

Primitive control systems require an accurate mathematical description of the test object This

dependency of the control system on the knowledge of test-object dynamics is clearly undesirable

Performance of a good control system should not be considerably affected by the dynamic interactions

and nonlinearities of the test object or by the nature of the excitation Proper selection of feedback signals

and control-system components can reduce such effects and will make the system robust

In the response-spectrum method of vibration testing it is customary to use displacement control at

low frequencies velocity control at intermediate frequency and acceleration control at high frequencies

This necessitates feedback of displacement velocity and acceleration responses Generally however the

most important feedback is the velocity feedback In sine-sweep tests the shaker velocity must change

steadily over the frequency band of interest In particular the velocity control must be precise near the

resonances of the test object Velocity (speed) feedback has a stabilizing effect on the dynamics which is

desirable This effect is particularly useful in ensuring stability in motion when testing is done near

resonances of lightly damped test objects On the contrary displacement (position) feedback can have a

destabilizing effect on some systems particularly when high feedback gains are used

The controller usually consists of various instruments equipment and computation hardware and

software Often the functions of the data-acquisition and processing system overlap with those of the

controller to some extent As an example consider the digital-controller of vibration testing apparatus

First the responses are measured through sensors (and transducers) filtered and amplified

(conditioned) These data channels may be passed through a multiplexer whose purpose is to select

one data channel at a time for processing Most modern data acquisition hardware does not need a

separate multiplexer to handle multiple signals The analog data are converted into digital data using

analog-to-digital converters (ADCs) The resulting sampled data are stored on a disk or as a block data in

the computer memory The reference input signal (typically a signal recorded on an FM tape) is also

sampled (if it is not already in the digital form) using an ADC and fed into the computer Digital

processing is done on the reference signal and the response data with the objective of computing the

command signal to drive the shaker The digital command signal is converted into an analog signal using

a digital-to-analog converter (DAC) and amplified (conditioned) before it is used to drive the exciter

The nature of the control components depends to a large extent on the nature and objectives of the

particular test to be conducted Some of the basic components in a shaker controller are described in

the following subsections

131 Components of a Shaker Controller

1311 Compressor

A compressor circuit is incorporated in automatic excitation control devices to control the excitation-

input level automatically The level of control depends on the feedback signal from a control sensor and

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copy 2007 by Taylor amp Francis Group LLC

the specified (reference) excitation signal Usually the compressor circuit is included in the excitation-

signal generator (for example in a sine generator) The control by this means may be done on the basis of

a single-frequency component (eg the fundamental frequency)

1312 Equalizer (Spectrum Shaper)

Random-signal equalizers are used to shape the spectrum of a random signal in a desired manner In

essence and equalizer consists of a bank of narrow-band filters (for example 80 filters) in parallel over

the operating frequency range By passing the signal through each filter the spectral density (or the mean

square value) of the signal in that narrow frequency band (for example each one-third-octave band) is

determined This is compared with the desired spectral level and automatic adjustment is made in that

filter in case there is an error In some systems response-spectrum analysis is made in place of power

spectral density analysis In that case the equalizer consists of a bank of simple oscillators whose

resonant frequencies are distributed over the operating frequency range of the equalizer The feedback

signal is passed through each oscillator and the peak value of its output is determined This value is

compared with the desired response spectrum value at that frequency If there is an error automatic gain

adjustment is made in the appropriate excitation signal components

Random-noise equalizers are used in conjunction with random signal generators They receive

feedback signals from the control sensors In some digital control systems there are algorithms (software)

that are used to iteratively converge the spectrum of the excitation signal felt by the test object into the

desired spectrum

1313 Tracking Filter

Many vibration tests are based on single-frequency excitations In such cases the control functions

should be performed on the basis of the amplitudes of the fundamental-frequency component of the

signal A tracking filter is simply a frequency-tuned band-pass filter It automatically tunes the center

frequency of its very narrow-band-pass filter to the frequency of a carrier signal Then when a noisy

signal is passed through the tuned filter the output of the filter will be the required fundamental

frequency component in the signal Tracking filters also are useful in obtaining amplitudendashfrequency

plots using an XndashY plotter In such cases the frequency value comes from the signal generator (sweep

oscillator) which produces the carrier signal to the tracking filter The tracking filter then determines the

corresponding amplitude of a signal that is fed into it Most tracking filters have dual channels so that two

signals can be handled (tracked) simultaneously

1314 Excitation Controller (Amplitude Servo-Monitor)

An excitation controller is typically an integral part of the signal generator It can be set so that automatic

sweep between two frequency limits can be performed at a selected sweep rate (linear or logarithmic)

More advanced excitation controllers have the capability of an automatic switch-over between constant-

displacement constant-velocity and constant-acceleration excitation-input control at specified

frequencies over the sweep frequency interval Consequently integrator circuits should be present

within the excitation controller unit to determine velocities and displacements from acceleration signals

Sometimes integration is performed by a separate unit called a vibration meter This unit also offers

the operator the capability of selecting the desired level of each signal (acceleration velocity or

displacement) There is an automatic cut-off level for large displacement values that could result from

noise in acceleration signals A compressor is also a subcomponent of the excitation controller The

complete unit is sometimes known as an amplitude servo-monitor

132 Signal-Generating Equipment

Shakers are force-generating devices that are operated using drive (excitation) signals generated from a

source The excitation-signal source is known as the signal generator Three major types of signal

generators are used in vibration testing applications (1) oscillators (2) random-signal generators and

(3) storage devices In some units oscillators and random-signal generators are combined We shall

Vibration Instrumentation 1-17

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copy 2007 by Taylor amp Francis Group LLC

discuss these two generators separately however because of their difference in function It also should be

noted that almost any digital signal (deterministic or random) can be generated by a digital computer

using a suitable computer program the signal eventually can be passed through a DAC to obtain

the corresponding analog signal These lsquodigitalrsquo signal generators along with analog sources such as

magnetic tape players (FM) are classified into the category of storage devices

The dynamic range of equipment is the ratio of the maximum and minimum output levels (expressed

in decibels) at which it is capable of operating without significant error This is an important specification

for many types of equipment particularly for signal-generating devices The output level of the signal

generator should be set to a value within its dynamic range

1321 Oscillators

Oscillators are essentially single-frequency generators Typically sine signals are generated but other

waveforms (such as rectangular and triangular pulses) are also available in most oscillators Normally

an oscillator has two modes of operation (1) sweeping up and down between two frequency limits and

(2) dwelling at a specified frequency In the sweep operation the sweep rate should be specified This can

be done either on a linear scale (Hzmin) or on a logarithmic scale (octavesmin) In the dwell operation

the frequency points (or intervals) should be specified In either case a desired signal level can be chosen

using the gain-control knob An oscillator that is operated exclusively in the sweep mode is called a sweep

oscillator

The early generation of oscillators employed variable inductor-capacitor types of electronic circuits to

generate signals oscillating at a desired frequency The oscillator is tuned to the required frequency by

varying the capacitance or inductance parameters A DC voltage is applied to energize the capacitor

and to obtain the desired oscillating voltage signal which subsequently is amplified and conditioned

Modern oscillators use operational amplifier circuits along with resistor capacitor and semiconductor

(SC) elements Also common are crystal (quartz) parallel-resonance oscillators used to generate voltage

signals accurately at a fixed frequency The circuit is activated using a DC-voltage source Other

frequencies of interest are obtained by passing this high-frequency signal through a frequency converter

The signal is then conditioned (amplified and filtered) Required shaping (for example rectangular

pulse) is obtained using a shape circuit Finally the required signal level is obtained by passing the

resulting signal through a variable-gain amplifier A block diagram of an oscillator illustrating various

stages in the generation of a periodic signal is given in Figure 113

A typical oscillator offers a choice of several (typically six) linear and logarithmic frequency ranges and

a sizable level of control capability (for example 80 dB) Upper and lower frequency limits in a sweep can

be preset on the front panel to any of the available frequency ranges Sweep-rate settings are continuously

DC Voltage

Oscillator

FrequencySpecification

FrequencyConverter

FilterAmplifier

ShaperPeriodicSignal

FrequencyCounter

Fixed-FrequencySignal

Variable-GainOutput

Amplifier

SignalSpecification

LevelSpecification

FIGURE 113 Block diagram of an oscillator-type signal generator

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  • 53191fm
    • Vibration Monitoring Testing and Instrumentation
      • Preface
      • Acknowledgments
      • Editor-in-Chief
      • Contributors
      • Contents
      • Related Titles
          • 53191ch1
            • Table of Contents
            • Chapter 1 Vibration Instrumentation
              • Summary
              • 11 Introduction
              • 12 Vibration Exciters
                • 121 Shaker Selection
                  • 1211 Force Rating
                  • 1212 Power Rating
                  • 1213 Stroke Rating
                  • 1214 Hydraulic Shakers
                  • 1215 Inertial Shakers
                  • 1216 Electromagnetic Shakers
                    • 122 Dynamics of Electromagnetic Shakers
                      • 1221 Transient Exciters
                          • 13 Control System
                            • 131 Components of a Shaker Controller
                              • 1311 Compressor
                              • 1312 Equalizer (Spectrum Shaper)
                              • 1313 Tracking Filter
                              • 1314 Excitation Controller (Amplitude Servo-Monitor)
                                • 132 Signal-Generating Equipment
                                  • 1321 Oscillators
                                  • 1322 Random Signal Generators
                                  • 1323 Tape Players
                                  • 1324 Data Processing
                                      • 14 Performance Specification
                                        • 141 Parameters for Performance Specification
                                          • 1411 Time-Domain Specifications
                                          • 1412 Frequency-Domain Specifications
                                            • 142 Linearity
                                            • 143 Instrument Ratings
                                              • 1431 Rating Parameters
                                                • 144 Accuracy and Precision
                                                  • 15 Motion Sensors and Transducers
                                                    • 151 Potentiometer
                                                      • 1511 Potentiometer Resolution
                                                      • 1512 Optical Potentiometer
                                                        • 152 Variable-Inductance Transducers
                                                          • 1521 Mutual-Induction Transducers
                                                          • 1522 Linear-Variable Differential Transformer
                                                          • 1523 Signal Conditioning
                                                            • 153 Mutual-Induction Proximity Sensor
                                                            • 154 Selfinduction Transducers
                                                            • 155 Permanent-Magnet Transducers
                                                            • 156 Alternating Current Permanent-Magnet Tachometer
                                                            • 157 Alternating Current Induction Tachometer
                                                            • 158 Eddy Current Transducers
                                                            • 159 Variable-Capacitance Transducers
                                                              • 1591 Capacitive Displacement Sensors
                                                              • 1592 Capacitive Angular Velocity Sensor
                                                              • 1593 Capacitance Bridge Circuit
                                                                • 1510 Piezoelectric Transducers
                                                                  • 15101 Sensitivity
                                                                  • 15102 Piezoelectric Accelerometer
                                                                  • 15103 Charge Amplifier
                                                                      • 16 Torque Force and Other Sensors
                                                                        • 161 Strain Gage Sensors
                                                                          • 1611 Equations for Strain Gage Measurements
                                                                          • 1612 Bridge Sensitivity
                                                                          • 1613 The Bridge Constant
                                                                          • 1614 The Calibration Constant
                                                                          • 1615 Data Acquisition
                                                                          • 1616 Accuracy Considerations
                                                                          • 1617 Semiconductor Strain Gages
                                                                          • 1618 Force and Torque Sensors
                                                                          • 1619 Strain Gage Torque Sensors
                                                                          • 16110 Deflection Torque Sensors
                                                                          • 16111 Variable-Reluctance Torque Sensor
                                                                          • 16112 Reaction Torque Sensors
                                                                            • 162 Miscellaneous Sensors
                                                                              • 1621 Stroboscope
                                                                              • 1622 Fiber Optic Sensors and Lasers
                                                                              • 1623 Fiber-Optic Gyroscope
                                                                              • 1624 Laser Doppler Interferometer
                                                                              • 1625 Ultrasonic Sensors
                                                                              • 1626 Gyroscopic Sensors
                                                                                  • References
                                                                                  • Appendix 1A Virtual Instrumentation for Data Acquisition Analysis and Presentation
                                                                                    • Summary
                                                                                    • List of Abbreviations
                                                                                    • 1A1 Dynamic Signals
                                                                                      • 1A11 Acquiring and Simulating Dynamic Signals
                                                                                        • 1A111 Aliasing
                                                                                        • 1A112 Time Continuity
                                                                                            • 1A2 Measurement Configuration Considerations
                                                                                              • 1A21 Input Signal Considerations
                                                                                                • 1A211 Input Pseudodifferential and Differential Configuration
                                                                                                • 1A212 Gain
                                                                                                • 1A213 Input Coupling
                                                                                                • 1A214 Integrated Electronic Piezoelectric Excitation
                                                                                                • 1A215 Nyquist Frequency and Bandwidth
                                                                                                • 1A216 Analog-to-Digital Conversion
                                                                                                • 1A217 Antialias Filters
                                                                                                • 1A218 Input Filter Delay
                                                                                                • 1A219 Overload Detection
                                                                                                  • 1A22 Output Signal Considerations
                                                                                                    • 1A221 Output Pseudodifferential and Differential Configuration
                                                                                                    • 1A222 Attenuation
                                                                                                    • 1A223 Digital-to-Analog Conversion
                                                                                                    • 1A224 Anti-imaging and Interpolation Filters
                                                                                                    • 1A225 Output Filter Delay
                                                                                                        • 1A3 Scaling and Calibration
                                                                                                          • 1A31 Scaling to Engineering Units
                                                                                                          • 1A32 Performing System Calibration
                                                                                                            • 1A321 Propagation Delay Calibration
                                                                                                                • 1A4 Limit Testing Analysis
                                                                                                                  • 1A41 Limit Testing Overview
                                                                                                                  • 1A42 Using the SVT Limit Testing VI
                                                                                                                    • 1A5 Integration
                                                                                                                      • 1A51 Introduction to Integration
                                                                                                                      • 1A52 Implementing Integration
                                                                                                                        • 1A521 Challenges when Integrating Vibration Data
                                                                                                                          • 1A53 Time-Domain Integration
                                                                                                                            • 1A531 Single-Shot Acquisition and Integration
                                                                                                                            • 1A532 Continuous Acquisition and Integration
                                                                                                                              • 1A54 Frequency-Domain Integration
                                                                                                                                • 1A6 Vibration-Level Measurements
                                                                                                                                  • 1A61 Measuring the Root Mean Square Level
                                                                                                                                    • 1A611 Single-Shot Buffered Acquisition
                                                                                                                                    • 1A612 Continuous Signal Acquisition
                                                                                                                                      • 1A62 Performing a Running RMS Level Measurement
                                                                                                                                      • 1A63 Computing the Peak Level
                                                                                                                                      • 1A64 Computing the Crest Factor
                                                                                                                                        • 1A7 Frequency Analysis
                                                                                                                                          • 1A71 FFT Fundamentals
                                                                                                                                            • 1A711 Number of Samples
                                                                                                                                            • 1A712 Frequency Resolution
                                                                                                                                            • 1A713 Maximum Resolvable Frequency
                                                                                                                                            • 1A714 Minimum Resolvable Frequency
                                                                                                                                            • 1A715 Number of Spectral Lines
                                                                                                                                            • 1A716 Relationship between Time-Domain and Frequency-Domain Specifications and Parameters
                                                                                                                                              • 1A72 Increasing Frequency Resolution
                                                                                                                                                • 1A721 Zoom FFT Analysis
                                                                                                                                                • 1A722 Frequency Resolution of the Zoom FFT VIs
                                                                                                                                                • 1A723 Zoom Measurement
                                                                                                                                                • 1A724 Zoom Settings
                                                                                                                                                • 1A725 Subset Analysis
                                                                                                                                                    • 1A8 Transient Analysis
                                                                                                                                                      • 1A81 Transient Analysis with the Sound and Vibration Toolkit
                                                                                                                                                      • 1A82 Performing an STFT vs Time
                                                                                                                                                        • 1A821 Selecting the FFT Block Size
                                                                                                                                                        • 1A822 Overlapping
                                                                                                                                                        • 1A823 Using the SVT STFT vs Time VI
                                                                                                                                                          • 1A83 Performing an STFT vs Rotational Speed
                                                                                                                                                            • 1A831 Converting the Pulse Train to Rotational Speed
                                                                                                                                                            • 1A832 STFT vs RPM
                                                                                                                                                              • 1A84 Measuring a Shock Response Spectrum
                                                                                                                                                                • 1A9 Waterfall Display
                                                                                                                                                                  • 1A91 Using the Display VIs
                                                                                                                                                                    • 1A911 Initializing the Display
                                                                                                                                                                    • 1A912 Sending Data to the Display
                                                                                                                                                                    • 1A913 Waterfall Display for Frequency Analysis
                                                                                                                                                                    • 1A914 Waterfall Display for Transient Analysis
                                                                                                                                                                    • 1A915 Waterfall Display for Octave Spectra
                                                                                                                                                                        • 1A10 Swept-Sine Measurements
                                                                                                                                                                          • 1A101 Swept-Sine Overview
                                                                                                                                                                          • 1A102 Choosing Swept-Sine vs FFT Measurements
                                                                                                                                                                          • 1A103 Taking a Swept-Sine Measurement
                                                                                                                                                                          • 1A104 Swept-Sine Measurement Example
                                                                                                                                                                              • Bibliography
                                                                                                                                                                              • Related Titles
                                                                                                                                                                                  • 53191ch2
                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                    • Chapter 2 Signal Conditioning and Modification
                                                                                                                                                                                      • Summary
                                                                                                                                                                                      • 21 Introduction
                                                                                                                                                                                      • 22 Amplifiers
                                                                                                                                                                                        • 221 Operational Amplifier
                                                                                                                                                                                        • 222 Use of Feedback in Opamp
                                                                                                                                                                                        • 223 Voltage Current and Power Amplifiers
                                                                                                                                                                                          • 2231 Charge Amplifiers
                                                                                                                                                                                            • 224 Instrumentation Amplifiers
                                                                                                                                                                                              • 2241 Differential Amplifier
                                                                                                                                                                                              • 2242 Common Mode
                                                                                                                                                                                                • 225 Amplifier Performance Ratings
                                                                                                                                                                                                  • 2251 Common-Mode Rejection Ratio
                                                                                                                                                                                                    • 226 Component Interconnection
                                                                                                                                                                                                      • 2261 Impedance Characteristics
                                                                                                                                                                                                      • 2262 Cascade Connection of Devices
                                                                                                                                                                                                      • 2263 AC-Coupled Ampliers
                                                                                                                                                                                                          • 23 Analog Filters
                                                                                                                                                                                                            • 231 Passive Filters and Active Filters
                                                                                                                                                                                                              • 2311 Number of Poles
                                                                                                                                                                                                                • 232 Low-Pass Filters
                                                                                                                                                                                                                  • 2321 Low-Pass Butterworth Filter
                                                                                                                                                                                                                    • 233 High-Pass Filters
                                                                                                                                                                                                                    • 234 Band-Pass Filters
                                                                                                                                                                                                                      • 2341 Resonance-Type Band-Pass Filters
                                                                                                                                                                                                                        • 235 Band-Reject Filters
                                                                                                                                                                                                                          • 24 Modulators and Demodulators
                                                                                                                                                                                                                            • 241 Amplitude Modulation
                                                                                                                                                                                                                              • 2411 Modulation Theorem
                                                                                                                                                                                                                              • 2412 Side Frequencies and Side Bands
                                                                                                                                                                                                                                • 242 Application of Amplitude Modulation
                                                                                                                                                                                                                                  • 2421 Fault Detection and Diagnosis
                                                                                                                                                                                                                                    • 243 Demodulation
                                                                                                                                                                                                                                      • 25 Analog ndashDigital Conversion
                                                                                                                                                                                                                                        • 251 Digital-to-Analog Conversion
                                                                                                                                                                                                                                          • 2511 DAC Error Sources
                                                                                                                                                                                                                                            • 252 Analog-to-Digital Conversion
                                                                                                                                                                                                                                            • 253 Analog-to-Digital Converter Performance Characteristics
                                                                                                                                                                                                                                              • 2531 Resolution and Quantization Error
                                                                                                                                                                                                                                              • 2532 Monotonicity Nonlinearity and Offset Error
                                                                                                                                                                                                                                              • 2533 Analog-to-Digital Converter Conversion Rate
                                                                                                                                                                                                                                                • 254 Sample-and-Hold Circuitry
                                                                                                                                                                                                                                                • 255 Digital Filters
                                                                                                                                                                                                                                                  • 2551 Software Implementation and Hardware Implementation
                                                                                                                                                                                                                                                      • 26 Bridge Circuits
                                                                                                                                                                                                                                                        • 261 Wheatstone Bridge
                                                                                                                                                                                                                                                        • 262 Constant-Current Bridge
                                                                                                                                                                                                                                                        • 263 Bridge Amplifiers
                                                                                                                                                                                                                                                          • 2631 Half-Bridge Circuits
                                                                                                                                                                                                                                                            • 264 Impedance Bridges
                                                                                                                                                                                                                                                              • 2641 Owen Bridge
                                                                                                                                                                                                                                                              • 2642 Wien-Bridge Oscillator
                                                                                                                                                                                                                                                                  • 27 Linearizing Devices
                                                                                                                                                                                                                                                                    • 271 Linearization by Software
                                                                                                                                                                                                                                                                    • 272 Linearization by Hardware Logic
                                                                                                                                                                                                                                                                    • 273 Analog Linearizing Circuitry
                                                                                                                                                                                                                                                                    • 274 Offsetting Circuitry
                                                                                                                                                                                                                                                                    • 275 Proportional-Output Circuitry
                                                                                                                                                                                                                                                                      • 2751 Curve-Shaping Circuitry
                                                                                                                                                                                                                                                                          • 28 Miscellaneous Signal Modification Circuitry
                                                                                                                                                                                                                                                                            • 281 Phase Shifters
                                                                                                                                                                                                                                                                            • 282 Voltage-to-Frequency Converter
                                                                                                                                                                                                                                                                            • 283 Frequency-to-Voltage Converter
                                                                                                                                                                                                                                                                            • 284 Voltage-to-Current Converters
                                                                                                                                                                                                                                                                            • 285 Peak-Hold Circuits
                                                                                                                                                                                                                                                                              • 29 Signal Analyzers and Display Devices
                                                                                                                                                                                                                                                                                • 291 Signal Analyzers
                                                                                                                                                                                                                                                                                • 292 Oscilloscopes
                                                                                                                                                                                                                                                                                  • 2921 Triggering
                                                                                                                                                                                                                                                                                  • 2922 Lissajous Patterns
                                                                                                                                                                                                                                                                                  • 2923 Digital Oscilloscopes
                                                                                                                                                                                                                                                                                      • Bibliography
                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                          • 53191ch3
                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                            • Chapter 3 Vibration Testing
                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                              • 31 Introduction
                                                                                                                                                                                                                                                                                              • 32 Representation of a Vibration Environment
                                                                                                                                                                                                                                                                                                • 321 Test Signals
                                                                                                                                                                                                                                                                                                  • 3211 Stochastic vs Deterministic Signals
                                                                                                                                                                                                                                                                                                    • 322 Deterministic Signal Representation
                                                                                                                                                                                                                                                                                                      • 3221 Single-Frequency Signals
                                                                                                                                                                                                                                                                                                      • 3222 Sine Sweep
                                                                                                                                                                                                                                                                                                      • 3223 Sine Dwell
                                                                                                                                                                                                                                                                                                      • 3224 Decaying Sine
                                                                                                                                                                                                                                                                                                      • 3225 Sine Beat
                                                                                                                                                                                                                                                                                                      • 3226 Sine Beat with Pauses
                                                                                                                                                                                                                                                                                                      • 3227 Multifrequency Signals
                                                                                                                                                                                                                                                                                                      • 3228 Actual Excitation Records
                                                                                                                                                                                                                                                                                                      • 3229 Simulated Excitation Signals
                                                                                                                                                                                                                                                                                                        • 323 Stochastic Signal Representation
                                                                                                                                                                                                                                                                                                          • 3231 Ergodic Random Signals
                                                                                                                                                                                                                                                                                                          • 3232 Stationary Random Signals
                                                                                                                                                                                                                                                                                                          • 3233 Independent and Uncorrelated Signals
                                                                                                                                                                                                                                                                                                          • 3234 Transmission of Random Excitations
                                                                                                                                                                                                                                                                                                            • 324 Frequency-Domain Representations
                                                                                                                                                                                                                                                                                                              • 3241 Fourier Spectrum Method
                                                                                                                                                                                                                                                                                                              • 3242 Power Spectral Density Method
                                                                                                                                                                                                                                                                                                                • 325 Response Spectrum
                                                                                                                                                                                                                                                                                                                  • 3251 Displacement Velocity and Acceleration Spectra
                                                                                                                                                                                                                                                                                                                  • 3252 Response-Spectra Plotting Paper
                                                                                                                                                                                                                                                                                                                  • 3253 Zero-Period Acceleration
                                                                                                                                                                                                                                                                                                                  • 3254 Uses of Response Spectra
                                                                                                                                                                                                                                                                                                                    • 326 Comparison of Various Representations
                                                                                                                                                                                                                                                                                                                      • 33 Pretest Procedures
                                                                                                                                                                                                                                                                                                                        • 331 Purpose of Testing
                                                                                                                                                                                                                                                                                                                        • 332 Service Functions
                                                                                                                                                                                                                                                                                                                          • 3321 Active Equipment
                                                                                                                                                                                                                                                                                                                          • 3322 Passive Equipment
                                                                                                                                                                                                                                                                                                                          • 3323 Functional Testing
                                                                                                                                                                                                                                                                                                                            • 333 Information Acquisition
                                                                                                                                                                                                                                                                                                                              • 3331 Interface Details
                                                                                                                                                                                                                                                                                                                              • 3332 Effect of Neglecting Interface Dynamics
                                                                                                                                                                                                                                                                                                                              • 3333 Effects of Damping
                                                                                                                                                                                                                                                                                                                              • 3334 Effects of Inertia
                                                                                                                                                                                                                                                                                                                              • 3335 Effect of Natural Frequency
                                                                                                                                                                                                                                                                                                                              • 3336 Effect of Excitation Frequency
                                                                                                                                                                                                                                                                                                                              • 3337 Other Effects of Interface
                                                                                                                                                                                                                                                                                                                                • 334 Test-Program Planning
                                                                                                                                                                                                                                                                                                                                  • 3341 Testing of Cabinet-Mounted Equipment
                                                                                                                                                                                                                                                                                                                                    • 335 Pretest Inspection
                                                                                                                                                                                                                                                                                                                                      • 34 Testing Procedures
                                                                                                                                                                                                                                                                                                                                        • 341 Resonance Search
                                                                                                                                                                                                                                                                                                                                        • 342 Methods of Determining Frequency-Response Functions
                                                                                                                                                                                                                                                                                                                                          • 3421 Fourier Transform Method
                                                                                                                                                                                                                                                                                                                                          • 3422 Spectral Density Method
                                                                                                                                                                                                                                                                                                                                          • 3423 Harmonic Excitation Method
                                                                                                                                                                                                                                                                                                                                            • 343 Resonance-Search Test Methods
                                                                                                                                                                                                                                                                                                                                              • 3431 Hammer (Bump) Test and Drop Test
                                                                                                                                                                                                                                                                                                                                              • 3432 Pluck Test
                                                                                                                                                                                                                                                                                                                                              • 3433 Shaker Tests
                                                                                                                                                                                                                                                                                                                                                • 344 Mechanical Aging
                                                                                                                                                                                                                                                                                                                                                  • 3441 Equivalence for Mechanical Aging
                                                                                                                                                                                                                                                                                                                                                  • 3442 Excitation-Intensity Equivalence
                                                                                                                                                                                                                                                                                                                                                  • 3443 Dynamic-Excitation Equivalence
                                                                                                                                                                                                                                                                                                                                                  • 3444 Cumulative Damage Theory
                                                                                                                                                                                                                                                                                                                                                    • 345 Test-Response Spectrum Generation
                                                                                                                                                                                                                                                                                                                                                    • 346 Instrument Calibration
                                                                                                                                                                                                                                                                                                                                                    • 347 Test-Object Mounting
                                                                                                                                                                                                                                                                                                                                                    • 348 Test-Input Considerations
                                                                                                                                                                                                                                                                                                                                                      • 3481 Test Nomenclature
                                                                                                                                                                                                                                                                                                                                                      • 3482 Testing with Uncorrelated Excitations
                                                                                                                                                                                                                                                                                                                                                      • 3483 Symmetrical Rectilinear Testing
                                                                                                                                                                                                                                                                                                                                                      • 3484 Geometry vs Dynamics
                                                                                                                                                                                                                                                                                                                                                      • 3485 Some Limitations
                                                                                                                                                                                                                                                                                                                                                      • 3486 Testing Black Boxes
                                                                                                                                                                                                                                                                                                                                                      • 3487 Phasing of Excitations
                                                                                                                                                                                                                                                                                                                                                      • 3488 Testing a Gray or White Box
                                                                                                                                                                                                                                                                                                                                                      • 3489 Overtesting in Multitest Sequences
                                                                                                                                                                                                                                                                                                                                                          • 35 Some Practical Information
                                                                                                                                                                                                                                                                                                                                                            • 351 Random Vibration Test Example
                                                                                                                                                                                                                                                                                                                                                            • 352 Vibration Shakers and Control Systems
                                                                                                                                                                                                                                                                                                                                                              • Bibliography
                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                  • 53191ch4
                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                    • Chapter 4 Experimental Modal Analysis
                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                      • 41 Introduction
                                                                                                                                                                                                                                                                                                                                                                      • 42 Frequency-Domain Formulation
                                                                                                                                                                                                                                                                                                                                                                        • 421 Transfer-Function Matrix
                                                                                                                                                                                                                                                                                                                                                                        • 422 Principle of Reciprocity
                                                                                                                                                                                                                                                                                                                                                                          • 43 Experimental Model Development
                                                                                                                                                                                                                                                                                                                                                                            • 431 Extraction of the Time-Domain Model
                                                                                                                                                                                                                                                                                                                                                                              • 44 Curve Fitting of Transfer Functions
                                                                                                                                                                                                                                                                                                                                                                                • 441 Problem Identification
                                                                                                                                                                                                                                                                                                                                                                                • 442 Single- and Multi-Degree-of-Freedom Techniques
                                                                                                                                                                                                                                                                                                                                                                                • 443 Single-Degree-of-Freedom Parameter Extraction in the Frequency Domain
                                                                                                                                                                                                                                                                                                                                                                                  • 4431 Circle-Fit Method
                                                                                                                                                                                                                                                                                                                                                                                    • Case of Viscous Damping
                                                                                                                                                                                                                                                                                                                                                                                    • Case of Hysteretic Damping
                                                                                                                                                                                                                                                                                                                                                                                      • 4432 Peak-Picking Method
                                                                                                                                                                                                                                                                                                                                                                                        • 444 Multi-Degree of Freedom Curve Fitting
                                                                                                                                                                                                                                                                                                                                                                                          • 4441 Formulation of the Method
                                                                                                                                                                                                                                                                                                                                                                                            • 445 A Comment on Static Modes and Rigid-Body Modes
                                                                                                                                                                                                                                                                                                                                                                                            • 446 Residue Extraction
                                                                                                                                                                                                                                                                                                                                                                                              • 45 Laboratory Experiments
                                                                                                                                                                                                                                                                                                                                                                                                • 451 Lumped-Parameter System
                                                                                                                                                                                                                                                                                                                                                                                                  • 4511 Frequency-Domain Test
                                                                                                                                                                                                                                                                                                                                                                                                  • 4512 Time-Domain Tests
                                                                                                                                                                                                                                                                                                                                                                                                    • 452 Distributed-Parameter System
                                                                                                                                                                                                                                                                                                                                                                                                      • 46 Commercial EMA Systems
                                                                                                                                                                                                                                                                                                                                                                                                        • 461 System Configuration
                                                                                                                                                                                                                                                                                                                                                                                                          • 4611 FFT Analysis Options
                                                                                                                                                                                                                                                                                                                                                                                                          • 4612 Modal Analysis Components
                                                                                                                                                                                                                                                                                                                                                                                                              • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                  • 53191ch5
                                                                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                    • Chapter 5 Mechanical Shock
                                                                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                      • 51 Definitions
                                                                                                                                                                                                                                                                                                                                                                                                                        • 511 Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 512 Simple (or Perfect) Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 513 Half-Sine Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 514 Versed-Sine (or Haversine) Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 515 Terminal Peak Sawtooth Shock or Final Peak Sawtooth Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 516 Rectangular Shock
                                                                                                                                                                                                                                                                                                                                                                                                                          • 5161 Trapezoidal Shock
                                                                                                                                                                                                                                                                                                                                                                                                                              • 52 Description in the Time Domain
                                                                                                                                                                                                                                                                                                                                                                                                                              • 53 Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                • 531 Need
                                                                                                                                                                                                                                                                                                                                                                                                                                • 532 Shock Response Spectrum Definition
                                                                                                                                                                                                                                                                                                                                                                                                                                • 533 Response of a Linear One-Degree-of-Freedom System
                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5331 Shock Defined by a Force
                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5332 Shock Defined by an Acceleration
                                                                                                                                                                                                                                                                                                                                                                                                                                    • 534 Definitions
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5341 Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5342 Absolute Acceleration Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5343 Relative Displacement Shock Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5344 Primary Positive Shock Response Spectrum or Initial Positive Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5345 Primary (or Initial) Negative Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5346 Secondary (or Residual) Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5347 Positive (or Maximum Positive) Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5348 Negative (or Maximum Negative) Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5349 Maximax Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53410 Choice of Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                        • 535 Standardized Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5351 Definition
                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5352 Standardized Shock Response Spectra of Simple Shocks
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53521 Half-Sine Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53522 Versed Sine Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53523 Terminal Peak Sawtooth Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53524 Rectangular Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53525 Trapezoidal Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 536 Choice of Damping
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 537 Shock Response Spectra Domains
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 538 Algorithms for Calculation of the Shock Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 539 Choice of the Digitization Frequency of the Signal
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5310 Use of Shock Response Spectra for the Study of Systems with Several Degrees of Freedom
                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 54 Pyroshocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 55 Use of Shock Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 551 Severity Comparison of Several Shocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 552 Test Specification Development from Real Environment Data
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5521 Synthesis of Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5522 Nature of the Specification
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5523 Choice of Shape
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5524 Amplitude
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5525 Duration
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5526 Difficulties
                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 56 Standards
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 561 Types of Standards
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 562 Installation Conditions of Test Item
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 563 Uncertainty Factor
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 564 Bump Test
                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 57 Damage Boundary Curve
                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 571 Definition
                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 572 Analysis of Test Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 58 Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 581 Main Types
                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 582 Impact Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5821 Universal Shock-Test Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 58211 Impact Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 58212 Impulse Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 583 Shock Simulators (Programmers)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5831 Half-Sine Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58311 Shock Duration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58312 Impact Velocity
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58313 Maximum Deformation of the Shock Simulator (Programmer)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58314 Shock Amplitude
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58315 Characteristics of the Target
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5832 Terminal Peak Sawtooth Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5833 Rectangular Pulse ndash Trapezoidal Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5834 Universal Shock Simulator (Programmer)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 58341 Generating a Half-Sine Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 58342 Generating a Terminal Peak Sawtooth Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 58343 Trapezoidal Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 584 Limitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5841 Limitations of the Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5842 Limitations of Shock Simulators
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 585 Pneumatic Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 586 High Impact Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5861 Lightweight High Impact Shock Machine
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5862 Medium Weight High Impact Shock Machine
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 587 Specific Test Facilities
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 59 Generation of Shock Using Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 591 Principle Behind the Generation of a Simple Shape Signal versus Time
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 592 Main Advantages
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 593 Pre- and Postshocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5931 Requirements
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5932 Solutions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 59321 Optimized Pre- and Postpulses
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5933 Incidence on the Shock Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 594 Limitations of Electrodynamic Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5941 Mechanical Limitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 59411 Abacuses
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5942 Electronic Limitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 595 The Use of Electrohydraulic Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 510 Control by a Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 5101 Principle
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 5102 Principal Shapes of Elementary Signals
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 51021 Decaying Sinusoid
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 51022 ZERD Function
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 51023 WAVSIN Waveform
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 5103 Comparison of WAVSIN SHOC Waveforms and Decaying Sinusoid
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 5104 Criticism of Control by a Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 511 Pyrotechnic Shock Simulation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5111 Simulation Using Pyrotechnic Facilities
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5112 Simulation Using Metal-to-Metal Impact
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5113 Simulation Using Electrodynamic Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5114 Simulation Using Conventional Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53191ch6
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Chapter 6 Machine Condition Monitoring and Fault Diagnostics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 61 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 62 Machinery Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 621 Causes of Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 622 Types of Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 623 Frequency of Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 63 Basic Maintenance Strategies
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 631 Run-to-Failure (Breakdown) Maintenance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 632 Scheduled (Preventative) Maintenance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 633 Condition-Based (Predictive Proactive Reliability Centered On-Condition) Maintenance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 64 Factors Which Influence Maintenance Strategy
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 65 Machine Condition Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 651 Periodic Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 652 Continuous Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 66 Transducer Selection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 661 Noncontact Displacement Transducers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 662 Velocity Transducers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 663 Acceleration Transducers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 67 Transducer Location
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 68 Recording and Analysis Instrumentation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 681 Vibration Meters
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 682 Data Collectors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 683 Frequency-Domain Analyzers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 684 Time-Domain Instruments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 685 Tracking Analyzers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 69 Display Formats and Analysis Tools
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 691 Time Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6911 Time-Waveform Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6912 Time-Waveform Indices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6913 Time-Synchronous Averaging
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6914 Negative Averaging
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6915 Orbits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6916 Probability Density Functions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6917 Probability Density Moments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 692 Frequency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6921 Band-Pass Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6922 Shock Pulse (Spike Energy)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6923 Enveloped Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6924 Signature Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6925 Cascades (Waterfall Plots)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6926 Masks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6927 Frequency-Domain Indices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 693 Modal Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 694 Quefrency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 610 Fault Detection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 6101 Standards
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61011 Standards Based on Machinery Type
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61012 Standards Based on Vibration Severity
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 6102 Acceptance Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 61021 Statistical Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 6103 Frequency-Domain Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61031 Limited Band Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61032 Constant Bandwidth Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61033 Constant Percentage Bandwidth Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 611 Fault Diagnostics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 6111 Forcing Functions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61111 Unbalance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61112 Misalignment
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61113 Mechanical Looseness
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61114 Soft Foot
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61115 Rubs
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61116 Resonances
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61117 Oil Whirl
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61118 Oil Whip
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61119 Structural Vibrations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 611110 Foundation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 6112 Specific Machine Components
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 61121 Damaged or Worn Rolling-Element Bearings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 61122 Damaged or Worn Gears
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 6113 Specific Machine Types
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61131 Pumps
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61132 Fans
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61133 Electric Motors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61134 Steam and Gas Turbines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61135 Compressors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61136 Reciprocating Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 6114 Advanced Fault Diagnostic Techniques
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 53191ch7
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • Chapter 7 Vibration-Based Tool Condition Monitoring Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 71 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 72 Mechanics of Turning
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 721 General Terms
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 722 Chatter Vibrations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 723 Tool Wear
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7231 Tool Failure Mechanisms
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7232 Tool Failure Modes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7233 Tool Wear Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7234 Tool Wear Stages
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 73 Vibration Signal Recording
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 731 Direct and Indirect Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 732 Sensor Requirements for Tool Wear Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 733 Force Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7331 Direct Measurement Dynamometers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7332 Indirect Force Sensors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7333 Piezoelectric Strain Sensors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7334 Resistance Strain Gauges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7335 Customized Force Sensors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 734 Acceleration Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 735 Acoustic Emission Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 736 Sensor Comparisons
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 74 Signal Processing for Sensor-Based Tool Condition Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 741 Feature Extraction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7411 Time Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7412 Frequency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7413 Statistical Processing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7414 TimendashFrequency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 742 Feature Selection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 75 Wear ModelDecision-Making for Sensor-Based Tool Condition Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 751 Trending Threshold
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 752 Neural Networks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7521 Unsupervised Networks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7522 Supervised Networks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 753 Fuzzy Logic
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 754 Other Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 76 Conclusion
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53191ch8
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Chapter 8 Fault Diagnosis of Helicopter Gearboxes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 81 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 82 Abnormality Scaling
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 83 The Structure-Based Connectionist Network
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 84 Sensor Location Selection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 841 Coverage Index
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 842 Overlap Index
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 843 Monitoring Effectiveness
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 85 A Case Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 851 Structural and Featural Influences
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 852 Evaluation of Influences
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 853 Fault Detection Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 854 Fault Diagnostic Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 8541 Faulty Subsystem Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 8542 Faulty Component Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 855 Sensor Location Evaluation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 856 Sensor Location Validation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 86 Conclusion
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 53191ch9
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Chapter 9 Vibration Suppression and Monitoring in Precision Motion Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 91 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 92 Mechanical Design to Minimize Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 921 Stability and Static Determinacy of Machine Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 922 Two-Dimensional Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 923 Three-Dimensional Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 93 Adaptive Notch Filter
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 931 Fast Fourier Transform
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 932 Simulation and Experiments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 94 Real-Time Vibration Analyzer
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 941 Learning Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 942 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 943 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 944 Experiments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 9441 Input Variables mdash the Evaluation Criteria
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 94411 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 94412 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 9442 Evaluation Rules
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 94421 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 94422 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 9443 Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 94431 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 94432 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 95 Practical Insights and Case Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 96 Conclusions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 53191ch10
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Chapter 10 Vibration and Shock Problems of Civil Engineering Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 101 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 102 Earthquake-Induced Vibration of Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1021 Seismicity and Ground Motions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1022 Influence of Local Site Conditions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1023 Response of Structures to Ground Motions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1024 Dynamic Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10241 Equations of Motion for Linear Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10242 Equations of Motion for Linear Multiple-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1025 Earthquake Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10251 Elastic Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10252 Smoothed Design Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10253 Ductility-Modified Response Spectrum Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1026 Design Philosophy and the Code Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10261 Performance-Based Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1027 Analysis Options for Earthquake Effects
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10271 Dynamic Time History Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10272 Response Spectrum Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 102721 Response Spectrum Analysis of Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 102722 Response Spectrum Analysis of Multi-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10273 Equivalent Static Analysis (Force-Based Approach)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10274 Displacement-Based Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1028 SoilndashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1029 Active and Passive Control Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 10210 Worked Examples
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 103 Dynamic Effects of Wind Loading on Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1031 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1032 Wind Speed
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1033 Design Structures for Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10331 Types of Wind Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10332 Design Criteria
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10333 Static Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1034 Along and Across-Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10341 Along-Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10342 Across-Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1035 Wind Tunnel Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1036 Comfort Criteria Human Response to Building Motion
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1037 Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1038 Comparison with Earthquake Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 104 Vibrations Due to Fluid ndashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1041 Added Mass and Inertial Coupling
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1042 Wave-Induced Vibration of Structure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 105 Blast Loading and Blast Effects on Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1051 Explosions and Blast Phenomenon
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1052 Explosive Air-Blast Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10521 Blast Wave Scaling Laws
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10522 Prediction of Blast Pressure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1053 Gas Explosion Loading and Effect of Internal Explosions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1054 Structural Response to Blast Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10541 Elastic Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10542 Elasto-Plastic Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1055 Material Behaviors at High Strain Rate
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10551 Dynamic Properties of Concrete under High Strain Rates
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10552 Dynamic Properties of Reinforcing Steel under High Strain Rates
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1056 Failure Modes of Blast-Loaded Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10561 Global Structural Behavior
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10562 Localized Structural Behavior
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10563 PressurendashImpulse ( PndashI ) Diagrams
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1057 Blast WavendashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1058 Effect of Ground Shocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10581 Loads from Air-Induced Ground Shock
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10582 Loads from Direct Ground Shock
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1059 Technical Design Manuals for Blast-Resistant Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 10510 Computer Programs for Blast and Shock Effects
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 106 Impact Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1061 Structural Impact between Two Bodies mdash Hard Impact and Soft Impact
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1062 Example mdash Aircraft Impact
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 107 Floor Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1071 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1072 Types of Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10721 Walking
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10722 Rhythmic Activities
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10723 Mechanical Equipment
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10724 Analysis Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1073 Natural Frequency of Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10731 Computing the Natural Frequency
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10732 Computing Deflection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10733 Damping
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10734 Resonance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1074 Vibration Caused by Walking
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10741 Minimum Natural Frequency
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1075 Design for Rhythmic Excitation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10751 Harmonics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10752 Minimum Natural Frequency
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1076 Example mdash Vibration Analysis of a Reinforced Concrete Floor
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 53191ch11
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Chapter 11 Seismic Base Isolation and Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 111 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1111 From Ductility Design to Base Isolation and Control Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1112 The Importance of Reducing Seismic Input and Response
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 112 Seismic Base Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1121 Historical Development of Base Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1122 Basic Principle
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1123 Issues in Seismic Base Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11231 Performance Criteria
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11232 Type of Structure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11233 Site Characteristics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11234 Retrofit Issues
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11235 Design of Building Services
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11236 Expected Life of Isolator
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1124 Seismic Isolation Devices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11241 Laminated Rubber Bearings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11242 Lead Rubber Bearing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11243 Friction-Based Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11244 Other Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1125 Design of Isolation Devices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11251 High-Damping Rubber Bearing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112511 Stability against Buckling
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112512 Stability against Roll Out
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11252 Lead Rubber Bearings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112521 Design of Lead Plug
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112522 Design of Laminated Rubber Bearing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11253 Design of Friction Pendulum System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1126 Verification of Properties of Isolation Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11261 Tests for Isolation Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 112611 System Characterization Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 112612 Prototype Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 112613 Quality Control Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11262 Uniform Building Code Recommendations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112621 Units Dependent on Loading Rates
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112622 Units Dependent on Bilateral Load
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112623 System Adequacy
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1127 Analysis of Base-Isolated Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11271 Modeling of a Superstructure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11272 Modeling of Isolation System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11273 Static Analysis Procedure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11274 Dynamic Analysis Procedure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 112741 Response Spectrum Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 112742 Time-History Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11275 Software for Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1128 Experimental Methods for Isolated Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1129 Implementation of Seismic Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11291 New Construction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112911 Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112912 Bridges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11292 Seismic Retrofit
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112921 Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112922 Bridges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11293 Other Implementations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 11210 Performance during Past Earthquakes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 112101 Performance of Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 112102 Performance of Bridges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 113 Seismic Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1131 Historical Development of Seismic Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1132 Basic Principles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11321 Passive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11322 Active Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11323 Semiactive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11324 Hybrid Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11325 Categorization of Basic Principles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1133 Important Issues in Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11331 SoilndashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11332 DevicendashStructure Interaction and Time Delay
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11333 Design Guidelines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1134 Vibration-Control Devices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11341 Passive Control Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113411 Metallic Yielding Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113412 Friction Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113413 Viscoelastic Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113414 Viscous Fluid Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113415 Tuned Mass Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11342 Active Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113421 Electromagnetic Actuator
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113422 Hydraulic Actuators
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11343 Semiactive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113431 Variable-Orifice Hydraulic Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113432 Controllable Fluid Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113433 Controllable Friction Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11344 Hybrid Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1135 Control Algorithm
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11351 Active Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11352 Semiactive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113521 Common Control Schemes for Controllable Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113522 Special Control Schemes for Controllable Damper
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1136 Experimental Performance Verification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11361 Shaking Table Tests of a Flexible Structural Model with TMD AMD and ATMD
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11362 Substructure Hybrid Test
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113621 Hybrid Tests Using Hydraulic Actuator
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113622 Hybrid Tests Using Shaking Table
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113623 Hybrid Tests Using Inertia-Force-Driven Loading System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1137 Implementations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11371 Semiactive Control of Full-Scale Structures Using Variable Joint Damper System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113711 Background of Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113712 Test System Set Up
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113713 Control Algorithm
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113714 Test Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11372 Application of Structural Control Technologies to Seismic Retrofit of a Cable-Stayed Bridge
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113721 Background of Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113722 Basic Concept of Seismic Retrofit
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113723 Modal Shape Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113724 Time-History Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113725 Soil ndash Structure Interaction Effect
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113726 Semiactive Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53191ch12
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Chapter 12 Seismic Random Vibration of Long-Span Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 121 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1211 Basic Concepts of Random Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12111 Stationary Random Process
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12112 Nonstationary Random Process
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1212 Three Methods for Structural Seismic Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12121 Response Spectrum Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12122 Time-History Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12123 Random Vibration Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 121231 Davenport Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 121232 Vanmarcke Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 12124 Comparisons of the Three Seismic-Analysis Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 122 Seismic Random-Excitation Fields
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1221 Power Spectral Density of Spatially Varying Ground Acceleration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1222 Several Coherence Models
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12221 FengndashHu Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12222 Harichandran ndashVanmarcke Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12223 LohndashYeh Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12224 OliveirandashHaondashPenzien Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12225 LucondashWong Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12226 QundashWangndashWang Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1223 Generation of Ground Acceleration Power Spectral Density Curves from Acceleration Response Spectrum Curves
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12231 Kaul Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12232 Iteration Scheme
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1224 Seismic Equations of Motion of Long-Span Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1225 Seismic Waves and Their Geometrical Expressions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 123 Pseudoexcitation Method for Structural Random Vibration Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1231 Structures Subjected to Stationary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12311 Single Stationary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12312 Multiple Stationary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1232 Structures Subjected to Nonstationary Random Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12321 Structures Subjected to Uniformly Modulated Evolutionary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 123211 Single Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 123212 Multiple Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12322 Structures Subjected to Nonuniformly Modulated Evolutionary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 123221 Single Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 123222 Multiple Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1233 Precise Integration Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12331 Precise Integration of Exponential Matrices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12332 Particular Solutions and Precise Integration Formulas for Various Forms of Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 123321 Linear Loading Form (HPD-L Form)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 123322 Sinusoidal Loading Form (HPD-S Form)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 123323 Exponentially Decaying Sinusoidal Loading Form (HPD-E Form)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 124 Long-Span Structures Subjected to Stationary Random Ground Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1241 The Solution of Equations of Motion Using the Pseudoexcitation Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1242 Numerical Comparisons with Other Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12421 Song-Hua-Jiang Suspension Bridge
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 124211 All Supports Move Uniformly
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 124212 Wave Passage Effect Is Taken into Account
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 124213 Wave-Passage Effect and Incoherence Effect Are Jointly Taken into Account
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 12422 San Joaquin Concrete Bridge
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 125 Long-Span Structures Subjected to Nonstationary Random Ground Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1251 Modulation Functions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1252 The Formulas for Nonstationary Multiexcitation Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1253 Expected Extreme Values of Nonstationary Random Processes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1254 Numerical Comparisons with the Corresponding Stationary Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 126 Conclusions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 53191ch13
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Chapter 13 Seismic Qualification of Equipment
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 131 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 132 Distribution Qualification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1321 Drive-Signal Generation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1322 Distribution Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1323 Test Procedures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 133 Seismic Qualification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1331 Stages of Seismic Qualification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1332 Test Preliminaries
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1333 Single-Frequency Testing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1334 Multifrequency Testing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1335 Generation of RRS Specifications
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 53191ch14
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Chapter 14 Human Response to Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 141 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 142 Vibration Excitations on Humans
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1421 Excitation Characteristics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 143 Human Response to Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1431 Vibration Perception
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1432 Frequency Weighting Curve
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1433 Iso-Perception Curves
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1434 Detection Threshold Curve
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 144 Regulation of Human Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1441 Acceptable Vibration Levels in Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1442 Whole-Body Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1443 HandndashArm Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
Page 28: Vibration Monitoring, Testing, and Instrumentationpreview.kingborn.net › 646000 › d1a74678d91943e5ba1d5e... · The MEMS Handbook, Second Edition MEMS: Introduction and Fundamentals

the test object at the shaker interface with the desired (specified) input The drive signal to the shaker is

modified depending on the error that is present

Two types of control are commonly employed in shaker apparatus simple manual control and

complex automatic control Manual control normally consists of simple open-loop trial-and-error

methods of manual adjustments (or calibration) of the control equipment to obtain a desired dynamic

response The actual response is usually monitored (on an oscilloscope or frequency analyzer screen for

example) during manual-control operations The pretest adjustments in manual control can be very

time-consuming as a result the test object might be subjected to overtesting which could produce

cumulative damage is undesirable and could defeat the test purpose Furthermore the calibration

procedure for the experimental setup must be repeated for each new test object

The disadvantages ofmanual control suggest that automatic control is desirable in complex test schemes

in which high accuracy of testing is desired The first step of automatic control involves automatic

measurement of the system response using control sensors and transducers The measurement is then fed

back into the control system which instantaneously determines the best drive signal to actuate the shaker

in order to get the desired excitation This may be done by either analog or digital methods

Primitive control systems require an accurate mathematical description of the test object This

dependency of the control system on the knowledge of test-object dynamics is clearly undesirable

Performance of a good control system should not be considerably affected by the dynamic interactions

and nonlinearities of the test object or by the nature of the excitation Proper selection of feedback signals

and control-system components can reduce such effects and will make the system robust

In the response-spectrum method of vibration testing it is customary to use displacement control at

low frequencies velocity control at intermediate frequency and acceleration control at high frequencies

This necessitates feedback of displacement velocity and acceleration responses Generally however the

most important feedback is the velocity feedback In sine-sweep tests the shaker velocity must change

steadily over the frequency band of interest In particular the velocity control must be precise near the

resonances of the test object Velocity (speed) feedback has a stabilizing effect on the dynamics which is

desirable This effect is particularly useful in ensuring stability in motion when testing is done near

resonances of lightly damped test objects On the contrary displacement (position) feedback can have a

destabilizing effect on some systems particularly when high feedback gains are used

The controller usually consists of various instruments equipment and computation hardware and

software Often the functions of the data-acquisition and processing system overlap with those of the

controller to some extent As an example consider the digital-controller of vibration testing apparatus

First the responses are measured through sensors (and transducers) filtered and amplified

(conditioned) These data channels may be passed through a multiplexer whose purpose is to select

one data channel at a time for processing Most modern data acquisition hardware does not need a

separate multiplexer to handle multiple signals The analog data are converted into digital data using

analog-to-digital converters (ADCs) The resulting sampled data are stored on a disk or as a block data in

the computer memory The reference input signal (typically a signal recorded on an FM tape) is also

sampled (if it is not already in the digital form) using an ADC and fed into the computer Digital

processing is done on the reference signal and the response data with the objective of computing the

command signal to drive the shaker The digital command signal is converted into an analog signal using

a digital-to-analog converter (DAC) and amplified (conditioned) before it is used to drive the exciter

The nature of the control components depends to a large extent on the nature and objectives of the

particular test to be conducted Some of the basic components in a shaker controller are described in

the following subsections

131 Components of a Shaker Controller

1311 Compressor

A compressor circuit is incorporated in automatic excitation control devices to control the excitation-

input level automatically The level of control depends on the feedback signal from a control sensor and

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the specified (reference) excitation signal Usually the compressor circuit is included in the excitation-

signal generator (for example in a sine generator) The control by this means may be done on the basis of

a single-frequency component (eg the fundamental frequency)

1312 Equalizer (Spectrum Shaper)

Random-signal equalizers are used to shape the spectrum of a random signal in a desired manner In

essence and equalizer consists of a bank of narrow-band filters (for example 80 filters) in parallel over

the operating frequency range By passing the signal through each filter the spectral density (or the mean

square value) of the signal in that narrow frequency band (for example each one-third-octave band) is

determined This is compared with the desired spectral level and automatic adjustment is made in that

filter in case there is an error In some systems response-spectrum analysis is made in place of power

spectral density analysis In that case the equalizer consists of a bank of simple oscillators whose

resonant frequencies are distributed over the operating frequency range of the equalizer The feedback

signal is passed through each oscillator and the peak value of its output is determined This value is

compared with the desired response spectrum value at that frequency If there is an error automatic gain

adjustment is made in the appropriate excitation signal components

Random-noise equalizers are used in conjunction with random signal generators They receive

feedback signals from the control sensors In some digital control systems there are algorithms (software)

that are used to iteratively converge the spectrum of the excitation signal felt by the test object into the

desired spectrum

1313 Tracking Filter

Many vibration tests are based on single-frequency excitations In such cases the control functions

should be performed on the basis of the amplitudes of the fundamental-frequency component of the

signal A tracking filter is simply a frequency-tuned band-pass filter It automatically tunes the center

frequency of its very narrow-band-pass filter to the frequency of a carrier signal Then when a noisy

signal is passed through the tuned filter the output of the filter will be the required fundamental

frequency component in the signal Tracking filters also are useful in obtaining amplitudendashfrequency

plots using an XndashY plotter In such cases the frequency value comes from the signal generator (sweep

oscillator) which produces the carrier signal to the tracking filter The tracking filter then determines the

corresponding amplitude of a signal that is fed into it Most tracking filters have dual channels so that two

signals can be handled (tracked) simultaneously

1314 Excitation Controller (Amplitude Servo-Monitor)

An excitation controller is typically an integral part of the signal generator It can be set so that automatic

sweep between two frequency limits can be performed at a selected sweep rate (linear or logarithmic)

More advanced excitation controllers have the capability of an automatic switch-over between constant-

displacement constant-velocity and constant-acceleration excitation-input control at specified

frequencies over the sweep frequency interval Consequently integrator circuits should be present

within the excitation controller unit to determine velocities and displacements from acceleration signals

Sometimes integration is performed by a separate unit called a vibration meter This unit also offers

the operator the capability of selecting the desired level of each signal (acceleration velocity or

displacement) There is an automatic cut-off level for large displacement values that could result from

noise in acceleration signals A compressor is also a subcomponent of the excitation controller The

complete unit is sometimes known as an amplitude servo-monitor

132 Signal-Generating Equipment

Shakers are force-generating devices that are operated using drive (excitation) signals generated from a

source The excitation-signal source is known as the signal generator Three major types of signal

generators are used in vibration testing applications (1) oscillators (2) random-signal generators and

(3) storage devices In some units oscillators and random-signal generators are combined We shall

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discuss these two generators separately however because of their difference in function It also should be

noted that almost any digital signal (deterministic or random) can be generated by a digital computer

using a suitable computer program the signal eventually can be passed through a DAC to obtain

the corresponding analog signal These lsquodigitalrsquo signal generators along with analog sources such as

magnetic tape players (FM) are classified into the category of storage devices

The dynamic range of equipment is the ratio of the maximum and minimum output levels (expressed

in decibels) at which it is capable of operating without significant error This is an important specification

for many types of equipment particularly for signal-generating devices The output level of the signal

generator should be set to a value within its dynamic range

1321 Oscillators

Oscillators are essentially single-frequency generators Typically sine signals are generated but other

waveforms (such as rectangular and triangular pulses) are also available in most oscillators Normally

an oscillator has two modes of operation (1) sweeping up and down between two frequency limits and

(2) dwelling at a specified frequency In the sweep operation the sweep rate should be specified This can

be done either on a linear scale (Hzmin) or on a logarithmic scale (octavesmin) In the dwell operation

the frequency points (or intervals) should be specified In either case a desired signal level can be chosen

using the gain-control knob An oscillator that is operated exclusively in the sweep mode is called a sweep

oscillator

The early generation of oscillators employed variable inductor-capacitor types of electronic circuits to

generate signals oscillating at a desired frequency The oscillator is tuned to the required frequency by

varying the capacitance or inductance parameters A DC voltage is applied to energize the capacitor

and to obtain the desired oscillating voltage signal which subsequently is amplified and conditioned

Modern oscillators use operational amplifier circuits along with resistor capacitor and semiconductor

(SC) elements Also common are crystal (quartz) parallel-resonance oscillators used to generate voltage

signals accurately at a fixed frequency The circuit is activated using a DC-voltage source Other

frequencies of interest are obtained by passing this high-frequency signal through a frequency converter

The signal is then conditioned (amplified and filtered) Required shaping (for example rectangular

pulse) is obtained using a shape circuit Finally the required signal level is obtained by passing the

resulting signal through a variable-gain amplifier A block diagram of an oscillator illustrating various

stages in the generation of a periodic signal is given in Figure 113

A typical oscillator offers a choice of several (typically six) linear and logarithmic frequency ranges and

a sizable level of control capability (for example 80 dB) Upper and lower frequency limits in a sweep can

be preset on the front panel to any of the available frequency ranges Sweep-rate settings are continuously

DC Voltage

Oscillator

FrequencySpecification

FrequencyConverter

FilterAmplifier

ShaperPeriodicSignal

FrequencyCounter

Fixed-FrequencySignal

Variable-GainOutput

Amplifier

SignalSpecification

LevelSpecification

FIGURE 113 Block diagram of an oscillator-type signal generator

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  • 53191fm
    • Vibration Monitoring Testing and Instrumentation
      • Preface
      • Acknowledgments
      • Editor-in-Chief
      • Contributors
      • Contents
      • Related Titles
          • 53191ch1
            • Table of Contents
            • Chapter 1 Vibration Instrumentation
              • Summary
              • 11 Introduction
              • 12 Vibration Exciters
                • 121 Shaker Selection
                  • 1211 Force Rating
                  • 1212 Power Rating
                  • 1213 Stroke Rating
                  • 1214 Hydraulic Shakers
                  • 1215 Inertial Shakers
                  • 1216 Electromagnetic Shakers
                    • 122 Dynamics of Electromagnetic Shakers
                      • 1221 Transient Exciters
                          • 13 Control System
                            • 131 Components of a Shaker Controller
                              • 1311 Compressor
                              • 1312 Equalizer (Spectrum Shaper)
                              • 1313 Tracking Filter
                              • 1314 Excitation Controller (Amplitude Servo-Monitor)
                                • 132 Signal-Generating Equipment
                                  • 1321 Oscillators
                                  • 1322 Random Signal Generators
                                  • 1323 Tape Players
                                  • 1324 Data Processing
                                      • 14 Performance Specification
                                        • 141 Parameters for Performance Specification
                                          • 1411 Time-Domain Specifications
                                          • 1412 Frequency-Domain Specifications
                                            • 142 Linearity
                                            • 143 Instrument Ratings
                                              • 1431 Rating Parameters
                                                • 144 Accuracy and Precision
                                                  • 15 Motion Sensors and Transducers
                                                    • 151 Potentiometer
                                                      • 1511 Potentiometer Resolution
                                                      • 1512 Optical Potentiometer
                                                        • 152 Variable-Inductance Transducers
                                                          • 1521 Mutual-Induction Transducers
                                                          • 1522 Linear-Variable Differential Transformer
                                                          • 1523 Signal Conditioning
                                                            • 153 Mutual-Induction Proximity Sensor
                                                            • 154 Selfinduction Transducers
                                                            • 155 Permanent-Magnet Transducers
                                                            • 156 Alternating Current Permanent-Magnet Tachometer
                                                            • 157 Alternating Current Induction Tachometer
                                                            • 158 Eddy Current Transducers
                                                            • 159 Variable-Capacitance Transducers
                                                              • 1591 Capacitive Displacement Sensors
                                                              • 1592 Capacitive Angular Velocity Sensor
                                                              • 1593 Capacitance Bridge Circuit
                                                                • 1510 Piezoelectric Transducers
                                                                  • 15101 Sensitivity
                                                                  • 15102 Piezoelectric Accelerometer
                                                                  • 15103 Charge Amplifier
                                                                      • 16 Torque Force and Other Sensors
                                                                        • 161 Strain Gage Sensors
                                                                          • 1611 Equations for Strain Gage Measurements
                                                                          • 1612 Bridge Sensitivity
                                                                          • 1613 The Bridge Constant
                                                                          • 1614 The Calibration Constant
                                                                          • 1615 Data Acquisition
                                                                          • 1616 Accuracy Considerations
                                                                          • 1617 Semiconductor Strain Gages
                                                                          • 1618 Force and Torque Sensors
                                                                          • 1619 Strain Gage Torque Sensors
                                                                          • 16110 Deflection Torque Sensors
                                                                          • 16111 Variable-Reluctance Torque Sensor
                                                                          • 16112 Reaction Torque Sensors
                                                                            • 162 Miscellaneous Sensors
                                                                              • 1621 Stroboscope
                                                                              • 1622 Fiber Optic Sensors and Lasers
                                                                              • 1623 Fiber-Optic Gyroscope
                                                                              • 1624 Laser Doppler Interferometer
                                                                              • 1625 Ultrasonic Sensors
                                                                              • 1626 Gyroscopic Sensors
                                                                                  • References
                                                                                  • Appendix 1A Virtual Instrumentation for Data Acquisition Analysis and Presentation
                                                                                    • Summary
                                                                                    • List of Abbreviations
                                                                                    • 1A1 Dynamic Signals
                                                                                      • 1A11 Acquiring and Simulating Dynamic Signals
                                                                                        • 1A111 Aliasing
                                                                                        • 1A112 Time Continuity
                                                                                            • 1A2 Measurement Configuration Considerations
                                                                                              • 1A21 Input Signal Considerations
                                                                                                • 1A211 Input Pseudodifferential and Differential Configuration
                                                                                                • 1A212 Gain
                                                                                                • 1A213 Input Coupling
                                                                                                • 1A214 Integrated Electronic Piezoelectric Excitation
                                                                                                • 1A215 Nyquist Frequency and Bandwidth
                                                                                                • 1A216 Analog-to-Digital Conversion
                                                                                                • 1A217 Antialias Filters
                                                                                                • 1A218 Input Filter Delay
                                                                                                • 1A219 Overload Detection
                                                                                                  • 1A22 Output Signal Considerations
                                                                                                    • 1A221 Output Pseudodifferential and Differential Configuration
                                                                                                    • 1A222 Attenuation
                                                                                                    • 1A223 Digital-to-Analog Conversion
                                                                                                    • 1A224 Anti-imaging and Interpolation Filters
                                                                                                    • 1A225 Output Filter Delay
                                                                                                        • 1A3 Scaling and Calibration
                                                                                                          • 1A31 Scaling to Engineering Units
                                                                                                          • 1A32 Performing System Calibration
                                                                                                            • 1A321 Propagation Delay Calibration
                                                                                                                • 1A4 Limit Testing Analysis
                                                                                                                  • 1A41 Limit Testing Overview
                                                                                                                  • 1A42 Using the SVT Limit Testing VI
                                                                                                                    • 1A5 Integration
                                                                                                                      • 1A51 Introduction to Integration
                                                                                                                      • 1A52 Implementing Integration
                                                                                                                        • 1A521 Challenges when Integrating Vibration Data
                                                                                                                          • 1A53 Time-Domain Integration
                                                                                                                            • 1A531 Single-Shot Acquisition and Integration
                                                                                                                            • 1A532 Continuous Acquisition and Integration
                                                                                                                              • 1A54 Frequency-Domain Integration
                                                                                                                                • 1A6 Vibration-Level Measurements
                                                                                                                                  • 1A61 Measuring the Root Mean Square Level
                                                                                                                                    • 1A611 Single-Shot Buffered Acquisition
                                                                                                                                    • 1A612 Continuous Signal Acquisition
                                                                                                                                      • 1A62 Performing a Running RMS Level Measurement
                                                                                                                                      • 1A63 Computing the Peak Level
                                                                                                                                      • 1A64 Computing the Crest Factor
                                                                                                                                        • 1A7 Frequency Analysis
                                                                                                                                          • 1A71 FFT Fundamentals
                                                                                                                                            • 1A711 Number of Samples
                                                                                                                                            • 1A712 Frequency Resolution
                                                                                                                                            • 1A713 Maximum Resolvable Frequency
                                                                                                                                            • 1A714 Minimum Resolvable Frequency
                                                                                                                                            • 1A715 Number of Spectral Lines
                                                                                                                                            • 1A716 Relationship between Time-Domain and Frequency-Domain Specifications and Parameters
                                                                                                                                              • 1A72 Increasing Frequency Resolution
                                                                                                                                                • 1A721 Zoom FFT Analysis
                                                                                                                                                • 1A722 Frequency Resolution of the Zoom FFT VIs
                                                                                                                                                • 1A723 Zoom Measurement
                                                                                                                                                • 1A724 Zoom Settings
                                                                                                                                                • 1A725 Subset Analysis
                                                                                                                                                    • 1A8 Transient Analysis
                                                                                                                                                      • 1A81 Transient Analysis with the Sound and Vibration Toolkit
                                                                                                                                                      • 1A82 Performing an STFT vs Time
                                                                                                                                                        • 1A821 Selecting the FFT Block Size
                                                                                                                                                        • 1A822 Overlapping
                                                                                                                                                        • 1A823 Using the SVT STFT vs Time VI
                                                                                                                                                          • 1A83 Performing an STFT vs Rotational Speed
                                                                                                                                                            • 1A831 Converting the Pulse Train to Rotational Speed
                                                                                                                                                            • 1A832 STFT vs RPM
                                                                                                                                                              • 1A84 Measuring a Shock Response Spectrum
                                                                                                                                                                • 1A9 Waterfall Display
                                                                                                                                                                  • 1A91 Using the Display VIs
                                                                                                                                                                    • 1A911 Initializing the Display
                                                                                                                                                                    • 1A912 Sending Data to the Display
                                                                                                                                                                    • 1A913 Waterfall Display for Frequency Analysis
                                                                                                                                                                    • 1A914 Waterfall Display for Transient Analysis
                                                                                                                                                                    • 1A915 Waterfall Display for Octave Spectra
                                                                                                                                                                        • 1A10 Swept-Sine Measurements
                                                                                                                                                                          • 1A101 Swept-Sine Overview
                                                                                                                                                                          • 1A102 Choosing Swept-Sine vs FFT Measurements
                                                                                                                                                                          • 1A103 Taking a Swept-Sine Measurement
                                                                                                                                                                          • 1A104 Swept-Sine Measurement Example
                                                                                                                                                                              • Bibliography
                                                                                                                                                                              • Related Titles
                                                                                                                                                                                  • 53191ch2
                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                    • Chapter 2 Signal Conditioning and Modification
                                                                                                                                                                                      • Summary
                                                                                                                                                                                      • 21 Introduction
                                                                                                                                                                                      • 22 Amplifiers
                                                                                                                                                                                        • 221 Operational Amplifier
                                                                                                                                                                                        • 222 Use of Feedback in Opamp
                                                                                                                                                                                        • 223 Voltage Current and Power Amplifiers
                                                                                                                                                                                          • 2231 Charge Amplifiers
                                                                                                                                                                                            • 224 Instrumentation Amplifiers
                                                                                                                                                                                              • 2241 Differential Amplifier
                                                                                                                                                                                              • 2242 Common Mode
                                                                                                                                                                                                • 225 Amplifier Performance Ratings
                                                                                                                                                                                                  • 2251 Common-Mode Rejection Ratio
                                                                                                                                                                                                    • 226 Component Interconnection
                                                                                                                                                                                                      • 2261 Impedance Characteristics
                                                                                                                                                                                                      • 2262 Cascade Connection of Devices
                                                                                                                                                                                                      • 2263 AC-Coupled Ampliers
                                                                                                                                                                                                          • 23 Analog Filters
                                                                                                                                                                                                            • 231 Passive Filters and Active Filters
                                                                                                                                                                                                              • 2311 Number of Poles
                                                                                                                                                                                                                • 232 Low-Pass Filters
                                                                                                                                                                                                                  • 2321 Low-Pass Butterworth Filter
                                                                                                                                                                                                                    • 233 High-Pass Filters
                                                                                                                                                                                                                    • 234 Band-Pass Filters
                                                                                                                                                                                                                      • 2341 Resonance-Type Band-Pass Filters
                                                                                                                                                                                                                        • 235 Band-Reject Filters
                                                                                                                                                                                                                          • 24 Modulators and Demodulators
                                                                                                                                                                                                                            • 241 Amplitude Modulation
                                                                                                                                                                                                                              • 2411 Modulation Theorem
                                                                                                                                                                                                                              • 2412 Side Frequencies and Side Bands
                                                                                                                                                                                                                                • 242 Application of Amplitude Modulation
                                                                                                                                                                                                                                  • 2421 Fault Detection and Diagnosis
                                                                                                                                                                                                                                    • 243 Demodulation
                                                                                                                                                                                                                                      • 25 Analog ndashDigital Conversion
                                                                                                                                                                                                                                        • 251 Digital-to-Analog Conversion
                                                                                                                                                                                                                                          • 2511 DAC Error Sources
                                                                                                                                                                                                                                            • 252 Analog-to-Digital Conversion
                                                                                                                                                                                                                                            • 253 Analog-to-Digital Converter Performance Characteristics
                                                                                                                                                                                                                                              • 2531 Resolution and Quantization Error
                                                                                                                                                                                                                                              • 2532 Monotonicity Nonlinearity and Offset Error
                                                                                                                                                                                                                                              • 2533 Analog-to-Digital Converter Conversion Rate
                                                                                                                                                                                                                                                • 254 Sample-and-Hold Circuitry
                                                                                                                                                                                                                                                • 255 Digital Filters
                                                                                                                                                                                                                                                  • 2551 Software Implementation and Hardware Implementation
                                                                                                                                                                                                                                                      • 26 Bridge Circuits
                                                                                                                                                                                                                                                        • 261 Wheatstone Bridge
                                                                                                                                                                                                                                                        • 262 Constant-Current Bridge
                                                                                                                                                                                                                                                        • 263 Bridge Amplifiers
                                                                                                                                                                                                                                                          • 2631 Half-Bridge Circuits
                                                                                                                                                                                                                                                            • 264 Impedance Bridges
                                                                                                                                                                                                                                                              • 2641 Owen Bridge
                                                                                                                                                                                                                                                              • 2642 Wien-Bridge Oscillator
                                                                                                                                                                                                                                                                  • 27 Linearizing Devices
                                                                                                                                                                                                                                                                    • 271 Linearization by Software
                                                                                                                                                                                                                                                                    • 272 Linearization by Hardware Logic
                                                                                                                                                                                                                                                                    • 273 Analog Linearizing Circuitry
                                                                                                                                                                                                                                                                    • 274 Offsetting Circuitry
                                                                                                                                                                                                                                                                    • 275 Proportional-Output Circuitry
                                                                                                                                                                                                                                                                      • 2751 Curve-Shaping Circuitry
                                                                                                                                                                                                                                                                          • 28 Miscellaneous Signal Modification Circuitry
                                                                                                                                                                                                                                                                            • 281 Phase Shifters
                                                                                                                                                                                                                                                                            • 282 Voltage-to-Frequency Converter
                                                                                                                                                                                                                                                                            • 283 Frequency-to-Voltage Converter
                                                                                                                                                                                                                                                                            • 284 Voltage-to-Current Converters
                                                                                                                                                                                                                                                                            • 285 Peak-Hold Circuits
                                                                                                                                                                                                                                                                              • 29 Signal Analyzers and Display Devices
                                                                                                                                                                                                                                                                                • 291 Signal Analyzers
                                                                                                                                                                                                                                                                                • 292 Oscilloscopes
                                                                                                                                                                                                                                                                                  • 2921 Triggering
                                                                                                                                                                                                                                                                                  • 2922 Lissajous Patterns
                                                                                                                                                                                                                                                                                  • 2923 Digital Oscilloscopes
                                                                                                                                                                                                                                                                                      • Bibliography
                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                          • 53191ch3
                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                            • Chapter 3 Vibration Testing
                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                              • 31 Introduction
                                                                                                                                                                                                                                                                                              • 32 Representation of a Vibration Environment
                                                                                                                                                                                                                                                                                                • 321 Test Signals
                                                                                                                                                                                                                                                                                                  • 3211 Stochastic vs Deterministic Signals
                                                                                                                                                                                                                                                                                                    • 322 Deterministic Signal Representation
                                                                                                                                                                                                                                                                                                      • 3221 Single-Frequency Signals
                                                                                                                                                                                                                                                                                                      • 3222 Sine Sweep
                                                                                                                                                                                                                                                                                                      • 3223 Sine Dwell
                                                                                                                                                                                                                                                                                                      • 3224 Decaying Sine
                                                                                                                                                                                                                                                                                                      • 3225 Sine Beat
                                                                                                                                                                                                                                                                                                      • 3226 Sine Beat with Pauses
                                                                                                                                                                                                                                                                                                      • 3227 Multifrequency Signals
                                                                                                                                                                                                                                                                                                      • 3228 Actual Excitation Records
                                                                                                                                                                                                                                                                                                      • 3229 Simulated Excitation Signals
                                                                                                                                                                                                                                                                                                        • 323 Stochastic Signal Representation
                                                                                                                                                                                                                                                                                                          • 3231 Ergodic Random Signals
                                                                                                                                                                                                                                                                                                          • 3232 Stationary Random Signals
                                                                                                                                                                                                                                                                                                          • 3233 Independent and Uncorrelated Signals
                                                                                                                                                                                                                                                                                                          • 3234 Transmission of Random Excitations
                                                                                                                                                                                                                                                                                                            • 324 Frequency-Domain Representations
                                                                                                                                                                                                                                                                                                              • 3241 Fourier Spectrum Method
                                                                                                                                                                                                                                                                                                              • 3242 Power Spectral Density Method
                                                                                                                                                                                                                                                                                                                • 325 Response Spectrum
                                                                                                                                                                                                                                                                                                                  • 3251 Displacement Velocity and Acceleration Spectra
                                                                                                                                                                                                                                                                                                                  • 3252 Response-Spectra Plotting Paper
                                                                                                                                                                                                                                                                                                                  • 3253 Zero-Period Acceleration
                                                                                                                                                                                                                                                                                                                  • 3254 Uses of Response Spectra
                                                                                                                                                                                                                                                                                                                    • 326 Comparison of Various Representations
                                                                                                                                                                                                                                                                                                                      • 33 Pretest Procedures
                                                                                                                                                                                                                                                                                                                        • 331 Purpose of Testing
                                                                                                                                                                                                                                                                                                                        • 332 Service Functions
                                                                                                                                                                                                                                                                                                                          • 3321 Active Equipment
                                                                                                                                                                                                                                                                                                                          • 3322 Passive Equipment
                                                                                                                                                                                                                                                                                                                          • 3323 Functional Testing
                                                                                                                                                                                                                                                                                                                            • 333 Information Acquisition
                                                                                                                                                                                                                                                                                                                              • 3331 Interface Details
                                                                                                                                                                                                                                                                                                                              • 3332 Effect of Neglecting Interface Dynamics
                                                                                                                                                                                                                                                                                                                              • 3333 Effects of Damping
                                                                                                                                                                                                                                                                                                                              • 3334 Effects of Inertia
                                                                                                                                                                                                                                                                                                                              • 3335 Effect of Natural Frequency
                                                                                                                                                                                                                                                                                                                              • 3336 Effect of Excitation Frequency
                                                                                                                                                                                                                                                                                                                              • 3337 Other Effects of Interface
                                                                                                                                                                                                                                                                                                                                • 334 Test-Program Planning
                                                                                                                                                                                                                                                                                                                                  • 3341 Testing of Cabinet-Mounted Equipment
                                                                                                                                                                                                                                                                                                                                    • 335 Pretest Inspection
                                                                                                                                                                                                                                                                                                                                      • 34 Testing Procedures
                                                                                                                                                                                                                                                                                                                                        • 341 Resonance Search
                                                                                                                                                                                                                                                                                                                                        • 342 Methods of Determining Frequency-Response Functions
                                                                                                                                                                                                                                                                                                                                          • 3421 Fourier Transform Method
                                                                                                                                                                                                                                                                                                                                          • 3422 Spectral Density Method
                                                                                                                                                                                                                                                                                                                                          • 3423 Harmonic Excitation Method
                                                                                                                                                                                                                                                                                                                                            • 343 Resonance-Search Test Methods
                                                                                                                                                                                                                                                                                                                                              • 3431 Hammer (Bump) Test and Drop Test
                                                                                                                                                                                                                                                                                                                                              • 3432 Pluck Test
                                                                                                                                                                                                                                                                                                                                              • 3433 Shaker Tests
                                                                                                                                                                                                                                                                                                                                                • 344 Mechanical Aging
                                                                                                                                                                                                                                                                                                                                                  • 3441 Equivalence for Mechanical Aging
                                                                                                                                                                                                                                                                                                                                                  • 3442 Excitation-Intensity Equivalence
                                                                                                                                                                                                                                                                                                                                                  • 3443 Dynamic-Excitation Equivalence
                                                                                                                                                                                                                                                                                                                                                  • 3444 Cumulative Damage Theory
                                                                                                                                                                                                                                                                                                                                                    • 345 Test-Response Spectrum Generation
                                                                                                                                                                                                                                                                                                                                                    • 346 Instrument Calibration
                                                                                                                                                                                                                                                                                                                                                    • 347 Test-Object Mounting
                                                                                                                                                                                                                                                                                                                                                    • 348 Test-Input Considerations
                                                                                                                                                                                                                                                                                                                                                      • 3481 Test Nomenclature
                                                                                                                                                                                                                                                                                                                                                      • 3482 Testing with Uncorrelated Excitations
                                                                                                                                                                                                                                                                                                                                                      • 3483 Symmetrical Rectilinear Testing
                                                                                                                                                                                                                                                                                                                                                      • 3484 Geometry vs Dynamics
                                                                                                                                                                                                                                                                                                                                                      • 3485 Some Limitations
                                                                                                                                                                                                                                                                                                                                                      • 3486 Testing Black Boxes
                                                                                                                                                                                                                                                                                                                                                      • 3487 Phasing of Excitations
                                                                                                                                                                                                                                                                                                                                                      • 3488 Testing a Gray or White Box
                                                                                                                                                                                                                                                                                                                                                      • 3489 Overtesting in Multitest Sequences
                                                                                                                                                                                                                                                                                                                                                          • 35 Some Practical Information
                                                                                                                                                                                                                                                                                                                                                            • 351 Random Vibration Test Example
                                                                                                                                                                                                                                                                                                                                                            • 352 Vibration Shakers and Control Systems
                                                                                                                                                                                                                                                                                                                                                              • Bibliography
                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                  • 53191ch4
                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                    • Chapter 4 Experimental Modal Analysis
                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                      • 41 Introduction
                                                                                                                                                                                                                                                                                                                                                                      • 42 Frequency-Domain Formulation
                                                                                                                                                                                                                                                                                                                                                                        • 421 Transfer-Function Matrix
                                                                                                                                                                                                                                                                                                                                                                        • 422 Principle of Reciprocity
                                                                                                                                                                                                                                                                                                                                                                          • 43 Experimental Model Development
                                                                                                                                                                                                                                                                                                                                                                            • 431 Extraction of the Time-Domain Model
                                                                                                                                                                                                                                                                                                                                                                              • 44 Curve Fitting of Transfer Functions
                                                                                                                                                                                                                                                                                                                                                                                • 441 Problem Identification
                                                                                                                                                                                                                                                                                                                                                                                • 442 Single- and Multi-Degree-of-Freedom Techniques
                                                                                                                                                                                                                                                                                                                                                                                • 443 Single-Degree-of-Freedom Parameter Extraction in the Frequency Domain
                                                                                                                                                                                                                                                                                                                                                                                  • 4431 Circle-Fit Method
                                                                                                                                                                                                                                                                                                                                                                                    • Case of Viscous Damping
                                                                                                                                                                                                                                                                                                                                                                                    • Case of Hysteretic Damping
                                                                                                                                                                                                                                                                                                                                                                                      • 4432 Peak-Picking Method
                                                                                                                                                                                                                                                                                                                                                                                        • 444 Multi-Degree of Freedom Curve Fitting
                                                                                                                                                                                                                                                                                                                                                                                          • 4441 Formulation of the Method
                                                                                                                                                                                                                                                                                                                                                                                            • 445 A Comment on Static Modes and Rigid-Body Modes
                                                                                                                                                                                                                                                                                                                                                                                            • 446 Residue Extraction
                                                                                                                                                                                                                                                                                                                                                                                              • 45 Laboratory Experiments
                                                                                                                                                                                                                                                                                                                                                                                                • 451 Lumped-Parameter System
                                                                                                                                                                                                                                                                                                                                                                                                  • 4511 Frequency-Domain Test
                                                                                                                                                                                                                                                                                                                                                                                                  • 4512 Time-Domain Tests
                                                                                                                                                                                                                                                                                                                                                                                                    • 452 Distributed-Parameter System
                                                                                                                                                                                                                                                                                                                                                                                                      • 46 Commercial EMA Systems
                                                                                                                                                                                                                                                                                                                                                                                                        • 461 System Configuration
                                                                                                                                                                                                                                                                                                                                                                                                          • 4611 FFT Analysis Options
                                                                                                                                                                                                                                                                                                                                                                                                          • 4612 Modal Analysis Components
                                                                                                                                                                                                                                                                                                                                                                                                              • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                  • 53191ch5
                                                                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                    • Chapter 5 Mechanical Shock
                                                                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                      • 51 Definitions
                                                                                                                                                                                                                                                                                                                                                                                                                        • 511 Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 512 Simple (or Perfect) Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 513 Half-Sine Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 514 Versed-Sine (or Haversine) Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 515 Terminal Peak Sawtooth Shock or Final Peak Sawtooth Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 516 Rectangular Shock
                                                                                                                                                                                                                                                                                                                                                                                                                          • 5161 Trapezoidal Shock
                                                                                                                                                                                                                                                                                                                                                                                                                              • 52 Description in the Time Domain
                                                                                                                                                                                                                                                                                                                                                                                                                              • 53 Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                • 531 Need
                                                                                                                                                                                                                                                                                                                                                                                                                                • 532 Shock Response Spectrum Definition
                                                                                                                                                                                                                                                                                                                                                                                                                                • 533 Response of a Linear One-Degree-of-Freedom System
                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5331 Shock Defined by a Force
                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5332 Shock Defined by an Acceleration
                                                                                                                                                                                                                                                                                                                                                                                                                                    • 534 Definitions
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5341 Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5342 Absolute Acceleration Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5343 Relative Displacement Shock Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5344 Primary Positive Shock Response Spectrum or Initial Positive Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5345 Primary (or Initial) Negative Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5346 Secondary (or Residual) Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5347 Positive (or Maximum Positive) Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5348 Negative (or Maximum Negative) Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5349 Maximax Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53410 Choice of Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                        • 535 Standardized Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5351 Definition
                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5352 Standardized Shock Response Spectra of Simple Shocks
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53521 Half-Sine Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53522 Versed Sine Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53523 Terminal Peak Sawtooth Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53524 Rectangular Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53525 Trapezoidal Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 536 Choice of Damping
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 537 Shock Response Spectra Domains
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 538 Algorithms for Calculation of the Shock Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 539 Choice of the Digitization Frequency of the Signal
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5310 Use of Shock Response Spectra for the Study of Systems with Several Degrees of Freedom
                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 54 Pyroshocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 55 Use of Shock Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 551 Severity Comparison of Several Shocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 552 Test Specification Development from Real Environment Data
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5521 Synthesis of Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5522 Nature of the Specification
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5523 Choice of Shape
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5524 Amplitude
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5525 Duration
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5526 Difficulties
                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 56 Standards
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 561 Types of Standards
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 562 Installation Conditions of Test Item
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 563 Uncertainty Factor
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 564 Bump Test
                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 57 Damage Boundary Curve
                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 571 Definition
                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 572 Analysis of Test Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 58 Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 581 Main Types
                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 582 Impact Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5821 Universal Shock-Test Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 58211 Impact Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 58212 Impulse Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 583 Shock Simulators (Programmers)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5831 Half-Sine Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58311 Shock Duration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58312 Impact Velocity
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58313 Maximum Deformation of the Shock Simulator (Programmer)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58314 Shock Amplitude
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58315 Characteristics of the Target
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5832 Terminal Peak Sawtooth Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5833 Rectangular Pulse ndash Trapezoidal Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5834 Universal Shock Simulator (Programmer)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 58341 Generating a Half-Sine Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 58342 Generating a Terminal Peak Sawtooth Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 58343 Trapezoidal Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 584 Limitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5841 Limitations of the Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5842 Limitations of Shock Simulators
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 585 Pneumatic Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 586 High Impact Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5861 Lightweight High Impact Shock Machine
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5862 Medium Weight High Impact Shock Machine
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 587 Specific Test Facilities
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 59 Generation of Shock Using Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 591 Principle Behind the Generation of a Simple Shape Signal versus Time
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 592 Main Advantages
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 593 Pre- and Postshocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5931 Requirements
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5932 Solutions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 59321 Optimized Pre- and Postpulses
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5933 Incidence on the Shock Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 594 Limitations of Electrodynamic Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5941 Mechanical Limitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 59411 Abacuses
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5942 Electronic Limitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 595 The Use of Electrohydraulic Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 510 Control by a Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 5101 Principle
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 5102 Principal Shapes of Elementary Signals
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 51021 Decaying Sinusoid
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 51022 ZERD Function
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 51023 WAVSIN Waveform
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 5103 Comparison of WAVSIN SHOC Waveforms and Decaying Sinusoid
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 5104 Criticism of Control by a Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 511 Pyrotechnic Shock Simulation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5111 Simulation Using Pyrotechnic Facilities
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5112 Simulation Using Metal-to-Metal Impact
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5113 Simulation Using Electrodynamic Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5114 Simulation Using Conventional Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53191ch6
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Chapter 6 Machine Condition Monitoring and Fault Diagnostics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 61 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 62 Machinery Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 621 Causes of Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 622 Types of Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 623 Frequency of Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 63 Basic Maintenance Strategies
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 631 Run-to-Failure (Breakdown) Maintenance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 632 Scheduled (Preventative) Maintenance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 633 Condition-Based (Predictive Proactive Reliability Centered On-Condition) Maintenance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 64 Factors Which Influence Maintenance Strategy
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 65 Machine Condition Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 651 Periodic Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 652 Continuous Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 66 Transducer Selection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 661 Noncontact Displacement Transducers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 662 Velocity Transducers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 663 Acceleration Transducers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 67 Transducer Location
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 68 Recording and Analysis Instrumentation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 681 Vibration Meters
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 682 Data Collectors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 683 Frequency-Domain Analyzers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 684 Time-Domain Instruments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 685 Tracking Analyzers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 69 Display Formats and Analysis Tools
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 691 Time Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6911 Time-Waveform Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6912 Time-Waveform Indices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6913 Time-Synchronous Averaging
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6914 Negative Averaging
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6915 Orbits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6916 Probability Density Functions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6917 Probability Density Moments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 692 Frequency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6921 Band-Pass Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6922 Shock Pulse (Spike Energy)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6923 Enveloped Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6924 Signature Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6925 Cascades (Waterfall Plots)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6926 Masks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6927 Frequency-Domain Indices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 693 Modal Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 694 Quefrency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 610 Fault Detection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 6101 Standards
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61011 Standards Based on Machinery Type
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61012 Standards Based on Vibration Severity
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 6102 Acceptance Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 61021 Statistical Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 6103 Frequency-Domain Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61031 Limited Band Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61032 Constant Bandwidth Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61033 Constant Percentage Bandwidth Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 611 Fault Diagnostics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 6111 Forcing Functions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61111 Unbalance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61112 Misalignment
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61113 Mechanical Looseness
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61114 Soft Foot
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61115 Rubs
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61116 Resonances
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61117 Oil Whirl
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61118 Oil Whip
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61119 Structural Vibrations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 611110 Foundation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 6112 Specific Machine Components
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 61121 Damaged or Worn Rolling-Element Bearings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 61122 Damaged or Worn Gears
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 6113 Specific Machine Types
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61131 Pumps
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61132 Fans
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61133 Electric Motors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61134 Steam and Gas Turbines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61135 Compressors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61136 Reciprocating Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 6114 Advanced Fault Diagnostic Techniques
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 53191ch7
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • Chapter 7 Vibration-Based Tool Condition Monitoring Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 71 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 72 Mechanics of Turning
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 721 General Terms
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 722 Chatter Vibrations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 723 Tool Wear
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7231 Tool Failure Mechanisms
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7232 Tool Failure Modes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7233 Tool Wear Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7234 Tool Wear Stages
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 73 Vibration Signal Recording
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 731 Direct and Indirect Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 732 Sensor Requirements for Tool Wear Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 733 Force Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7331 Direct Measurement Dynamometers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7332 Indirect Force Sensors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7333 Piezoelectric Strain Sensors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7334 Resistance Strain Gauges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7335 Customized Force Sensors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 734 Acceleration Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 735 Acoustic Emission Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 736 Sensor Comparisons
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 74 Signal Processing for Sensor-Based Tool Condition Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 741 Feature Extraction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7411 Time Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7412 Frequency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7413 Statistical Processing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7414 TimendashFrequency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 742 Feature Selection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 75 Wear ModelDecision-Making for Sensor-Based Tool Condition Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 751 Trending Threshold
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 752 Neural Networks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7521 Unsupervised Networks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7522 Supervised Networks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 753 Fuzzy Logic
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 754 Other Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 76 Conclusion
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53191ch8
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Chapter 8 Fault Diagnosis of Helicopter Gearboxes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 81 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 82 Abnormality Scaling
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 83 The Structure-Based Connectionist Network
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 84 Sensor Location Selection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 841 Coverage Index
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 842 Overlap Index
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 843 Monitoring Effectiveness
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 85 A Case Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 851 Structural and Featural Influences
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 852 Evaluation of Influences
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 853 Fault Detection Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 854 Fault Diagnostic Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 8541 Faulty Subsystem Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 8542 Faulty Component Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 855 Sensor Location Evaluation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 856 Sensor Location Validation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 86 Conclusion
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 53191ch9
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Chapter 9 Vibration Suppression and Monitoring in Precision Motion Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 91 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 92 Mechanical Design to Minimize Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 921 Stability and Static Determinacy of Machine Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 922 Two-Dimensional Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 923 Three-Dimensional Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 93 Adaptive Notch Filter
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 931 Fast Fourier Transform
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 932 Simulation and Experiments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 94 Real-Time Vibration Analyzer
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 941 Learning Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 942 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 943 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 944 Experiments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 9441 Input Variables mdash the Evaluation Criteria
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 94411 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 94412 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 9442 Evaluation Rules
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 94421 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 94422 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 9443 Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 94431 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 94432 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 95 Practical Insights and Case Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 96 Conclusions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 53191ch10
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Chapter 10 Vibration and Shock Problems of Civil Engineering Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 101 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 102 Earthquake-Induced Vibration of Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1021 Seismicity and Ground Motions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1022 Influence of Local Site Conditions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1023 Response of Structures to Ground Motions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1024 Dynamic Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10241 Equations of Motion for Linear Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10242 Equations of Motion for Linear Multiple-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1025 Earthquake Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10251 Elastic Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10252 Smoothed Design Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10253 Ductility-Modified Response Spectrum Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1026 Design Philosophy and the Code Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10261 Performance-Based Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1027 Analysis Options for Earthquake Effects
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10271 Dynamic Time History Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10272 Response Spectrum Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 102721 Response Spectrum Analysis of Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 102722 Response Spectrum Analysis of Multi-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10273 Equivalent Static Analysis (Force-Based Approach)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10274 Displacement-Based Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1028 SoilndashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1029 Active and Passive Control Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 10210 Worked Examples
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 103 Dynamic Effects of Wind Loading on Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1031 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1032 Wind Speed
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1033 Design Structures for Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10331 Types of Wind Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10332 Design Criteria
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10333 Static Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1034 Along and Across-Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10341 Along-Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10342 Across-Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1035 Wind Tunnel Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1036 Comfort Criteria Human Response to Building Motion
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1037 Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1038 Comparison with Earthquake Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 104 Vibrations Due to Fluid ndashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1041 Added Mass and Inertial Coupling
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1042 Wave-Induced Vibration of Structure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 105 Blast Loading and Blast Effects on Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1051 Explosions and Blast Phenomenon
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1052 Explosive Air-Blast Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10521 Blast Wave Scaling Laws
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10522 Prediction of Blast Pressure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1053 Gas Explosion Loading and Effect of Internal Explosions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1054 Structural Response to Blast Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10541 Elastic Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10542 Elasto-Plastic Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1055 Material Behaviors at High Strain Rate
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10551 Dynamic Properties of Concrete under High Strain Rates
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10552 Dynamic Properties of Reinforcing Steel under High Strain Rates
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1056 Failure Modes of Blast-Loaded Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10561 Global Structural Behavior
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10562 Localized Structural Behavior
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10563 PressurendashImpulse ( PndashI ) Diagrams
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1057 Blast WavendashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1058 Effect of Ground Shocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10581 Loads from Air-Induced Ground Shock
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10582 Loads from Direct Ground Shock
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1059 Technical Design Manuals for Blast-Resistant Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 10510 Computer Programs for Blast and Shock Effects
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 106 Impact Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1061 Structural Impact between Two Bodies mdash Hard Impact and Soft Impact
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1062 Example mdash Aircraft Impact
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 107 Floor Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1071 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1072 Types of Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10721 Walking
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10722 Rhythmic Activities
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10723 Mechanical Equipment
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10724 Analysis Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1073 Natural Frequency of Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10731 Computing the Natural Frequency
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10732 Computing Deflection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10733 Damping
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10734 Resonance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1074 Vibration Caused by Walking
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10741 Minimum Natural Frequency
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1075 Design for Rhythmic Excitation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10751 Harmonics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10752 Minimum Natural Frequency
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1076 Example mdash Vibration Analysis of a Reinforced Concrete Floor
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 53191ch11
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Chapter 11 Seismic Base Isolation and Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 111 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1111 From Ductility Design to Base Isolation and Control Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1112 The Importance of Reducing Seismic Input and Response
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 112 Seismic Base Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1121 Historical Development of Base Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1122 Basic Principle
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1123 Issues in Seismic Base Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11231 Performance Criteria
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11232 Type of Structure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11233 Site Characteristics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11234 Retrofit Issues
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11235 Design of Building Services
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11236 Expected Life of Isolator
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1124 Seismic Isolation Devices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11241 Laminated Rubber Bearings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11242 Lead Rubber Bearing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11243 Friction-Based Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11244 Other Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1125 Design of Isolation Devices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11251 High-Damping Rubber Bearing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112511 Stability against Buckling
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112512 Stability against Roll Out
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11252 Lead Rubber Bearings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112521 Design of Lead Plug
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112522 Design of Laminated Rubber Bearing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11253 Design of Friction Pendulum System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1126 Verification of Properties of Isolation Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11261 Tests for Isolation Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 112611 System Characterization Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 112612 Prototype Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 112613 Quality Control Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11262 Uniform Building Code Recommendations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112621 Units Dependent on Loading Rates
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112622 Units Dependent on Bilateral Load
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112623 System Adequacy
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1127 Analysis of Base-Isolated Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11271 Modeling of a Superstructure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11272 Modeling of Isolation System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11273 Static Analysis Procedure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11274 Dynamic Analysis Procedure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 112741 Response Spectrum Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 112742 Time-History Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11275 Software for Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1128 Experimental Methods for Isolated Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1129 Implementation of Seismic Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11291 New Construction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112911 Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112912 Bridges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11292 Seismic Retrofit
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112921 Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112922 Bridges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11293 Other Implementations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 11210 Performance during Past Earthquakes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 112101 Performance of Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 112102 Performance of Bridges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 113 Seismic Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1131 Historical Development of Seismic Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1132 Basic Principles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11321 Passive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11322 Active Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11323 Semiactive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11324 Hybrid Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11325 Categorization of Basic Principles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1133 Important Issues in Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11331 SoilndashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11332 DevicendashStructure Interaction and Time Delay
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11333 Design Guidelines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1134 Vibration-Control Devices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11341 Passive Control Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113411 Metallic Yielding Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113412 Friction Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113413 Viscoelastic Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113414 Viscous Fluid Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113415 Tuned Mass Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11342 Active Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113421 Electromagnetic Actuator
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113422 Hydraulic Actuators
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11343 Semiactive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113431 Variable-Orifice Hydraulic Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113432 Controllable Fluid Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113433 Controllable Friction Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11344 Hybrid Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1135 Control Algorithm
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11351 Active Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11352 Semiactive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113521 Common Control Schemes for Controllable Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113522 Special Control Schemes for Controllable Damper
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1136 Experimental Performance Verification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11361 Shaking Table Tests of a Flexible Structural Model with TMD AMD and ATMD
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11362 Substructure Hybrid Test
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113621 Hybrid Tests Using Hydraulic Actuator
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113622 Hybrid Tests Using Shaking Table
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113623 Hybrid Tests Using Inertia-Force-Driven Loading System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1137 Implementations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11371 Semiactive Control of Full-Scale Structures Using Variable Joint Damper System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113711 Background of Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113712 Test System Set Up
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113713 Control Algorithm
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113714 Test Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11372 Application of Structural Control Technologies to Seismic Retrofit of a Cable-Stayed Bridge
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113721 Background of Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113722 Basic Concept of Seismic Retrofit
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113723 Modal Shape Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113724 Time-History Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113725 Soil ndash Structure Interaction Effect
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113726 Semiactive Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53191ch12
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Chapter 12 Seismic Random Vibration of Long-Span Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 121 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1211 Basic Concepts of Random Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12111 Stationary Random Process
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12112 Nonstationary Random Process
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1212 Three Methods for Structural Seismic Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12121 Response Spectrum Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12122 Time-History Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12123 Random Vibration Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 121231 Davenport Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 121232 Vanmarcke Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 12124 Comparisons of the Three Seismic-Analysis Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 122 Seismic Random-Excitation Fields
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1221 Power Spectral Density of Spatially Varying Ground Acceleration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1222 Several Coherence Models
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12221 FengndashHu Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12222 Harichandran ndashVanmarcke Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12223 LohndashYeh Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12224 OliveirandashHaondashPenzien Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12225 LucondashWong Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12226 QundashWangndashWang Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1223 Generation of Ground Acceleration Power Spectral Density Curves from Acceleration Response Spectrum Curves
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12231 Kaul Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12232 Iteration Scheme
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1224 Seismic Equations of Motion of Long-Span Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1225 Seismic Waves and Their Geometrical Expressions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 123 Pseudoexcitation Method for Structural Random Vibration Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1231 Structures Subjected to Stationary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12311 Single Stationary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12312 Multiple Stationary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1232 Structures Subjected to Nonstationary Random Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12321 Structures Subjected to Uniformly Modulated Evolutionary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 123211 Single Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 123212 Multiple Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12322 Structures Subjected to Nonuniformly Modulated Evolutionary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 123221 Single Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 123222 Multiple Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1233 Precise Integration Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12331 Precise Integration of Exponential Matrices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12332 Particular Solutions and Precise Integration Formulas for Various Forms of Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 123321 Linear Loading Form (HPD-L Form)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 123322 Sinusoidal Loading Form (HPD-S Form)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 123323 Exponentially Decaying Sinusoidal Loading Form (HPD-E Form)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 124 Long-Span Structures Subjected to Stationary Random Ground Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1241 The Solution of Equations of Motion Using the Pseudoexcitation Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1242 Numerical Comparisons with Other Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12421 Song-Hua-Jiang Suspension Bridge
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 124211 All Supports Move Uniformly
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 124212 Wave Passage Effect Is Taken into Account
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 124213 Wave-Passage Effect and Incoherence Effect Are Jointly Taken into Account
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 12422 San Joaquin Concrete Bridge
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 125 Long-Span Structures Subjected to Nonstationary Random Ground Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1251 Modulation Functions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1252 The Formulas for Nonstationary Multiexcitation Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1253 Expected Extreme Values of Nonstationary Random Processes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1254 Numerical Comparisons with the Corresponding Stationary Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 126 Conclusions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 53191ch13
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Chapter 13 Seismic Qualification of Equipment
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 131 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 132 Distribution Qualification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1321 Drive-Signal Generation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1322 Distribution Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1323 Test Procedures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 133 Seismic Qualification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1331 Stages of Seismic Qualification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1332 Test Preliminaries
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1333 Single-Frequency Testing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1334 Multifrequency Testing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1335 Generation of RRS Specifications
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 53191ch14
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Chapter 14 Human Response to Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 141 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 142 Vibration Excitations on Humans
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1421 Excitation Characteristics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 143 Human Response to Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1431 Vibration Perception
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1432 Frequency Weighting Curve
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1433 Iso-Perception Curves
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1434 Detection Threshold Curve
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 144 Regulation of Human Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1441 Acceptable Vibration Levels in Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1442 Whole-Body Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1443 HandndashArm Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
Page 29: Vibration Monitoring, Testing, and Instrumentationpreview.kingborn.net › 646000 › d1a74678d91943e5ba1d5e... · The MEMS Handbook, Second Edition MEMS: Introduction and Fundamentals

the specified (reference) excitation signal Usually the compressor circuit is included in the excitation-

signal generator (for example in a sine generator) The control by this means may be done on the basis of

a single-frequency component (eg the fundamental frequency)

1312 Equalizer (Spectrum Shaper)

Random-signal equalizers are used to shape the spectrum of a random signal in a desired manner In

essence and equalizer consists of a bank of narrow-band filters (for example 80 filters) in parallel over

the operating frequency range By passing the signal through each filter the spectral density (or the mean

square value) of the signal in that narrow frequency band (for example each one-third-octave band) is

determined This is compared with the desired spectral level and automatic adjustment is made in that

filter in case there is an error In some systems response-spectrum analysis is made in place of power

spectral density analysis In that case the equalizer consists of a bank of simple oscillators whose

resonant frequencies are distributed over the operating frequency range of the equalizer The feedback

signal is passed through each oscillator and the peak value of its output is determined This value is

compared with the desired response spectrum value at that frequency If there is an error automatic gain

adjustment is made in the appropriate excitation signal components

Random-noise equalizers are used in conjunction with random signal generators They receive

feedback signals from the control sensors In some digital control systems there are algorithms (software)

that are used to iteratively converge the spectrum of the excitation signal felt by the test object into the

desired spectrum

1313 Tracking Filter

Many vibration tests are based on single-frequency excitations In such cases the control functions

should be performed on the basis of the amplitudes of the fundamental-frequency component of the

signal A tracking filter is simply a frequency-tuned band-pass filter It automatically tunes the center

frequency of its very narrow-band-pass filter to the frequency of a carrier signal Then when a noisy

signal is passed through the tuned filter the output of the filter will be the required fundamental

frequency component in the signal Tracking filters also are useful in obtaining amplitudendashfrequency

plots using an XndashY plotter In such cases the frequency value comes from the signal generator (sweep

oscillator) which produces the carrier signal to the tracking filter The tracking filter then determines the

corresponding amplitude of a signal that is fed into it Most tracking filters have dual channels so that two

signals can be handled (tracked) simultaneously

1314 Excitation Controller (Amplitude Servo-Monitor)

An excitation controller is typically an integral part of the signal generator It can be set so that automatic

sweep between two frequency limits can be performed at a selected sweep rate (linear or logarithmic)

More advanced excitation controllers have the capability of an automatic switch-over between constant-

displacement constant-velocity and constant-acceleration excitation-input control at specified

frequencies over the sweep frequency interval Consequently integrator circuits should be present

within the excitation controller unit to determine velocities and displacements from acceleration signals

Sometimes integration is performed by a separate unit called a vibration meter This unit also offers

the operator the capability of selecting the desired level of each signal (acceleration velocity or

displacement) There is an automatic cut-off level for large displacement values that could result from

noise in acceleration signals A compressor is also a subcomponent of the excitation controller The

complete unit is sometimes known as an amplitude servo-monitor

132 Signal-Generating Equipment

Shakers are force-generating devices that are operated using drive (excitation) signals generated from a

source The excitation-signal source is known as the signal generator Three major types of signal

generators are used in vibration testing applications (1) oscillators (2) random-signal generators and

(3) storage devices In some units oscillators and random-signal generators are combined We shall

Vibration Instrumentation 1-17

53191mdash522007mdash1202mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

discuss these two generators separately however because of their difference in function It also should be

noted that almost any digital signal (deterministic or random) can be generated by a digital computer

using a suitable computer program the signal eventually can be passed through a DAC to obtain

the corresponding analog signal These lsquodigitalrsquo signal generators along with analog sources such as

magnetic tape players (FM) are classified into the category of storage devices

The dynamic range of equipment is the ratio of the maximum and minimum output levels (expressed

in decibels) at which it is capable of operating without significant error This is an important specification

for many types of equipment particularly for signal-generating devices The output level of the signal

generator should be set to a value within its dynamic range

1321 Oscillators

Oscillators are essentially single-frequency generators Typically sine signals are generated but other

waveforms (such as rectangular and triangular pulses) are also available in most oscillators Normally

an oscillator has two modes of operation (1) sweeping up and down between two frequency limits and

(2) dwelling at a specified frequency In the sweep operation the sweep rate should be specified This can

be done either on a linear scale (Hzmin) or on a logarithmic scale (octavesmin) In the dwell operation

the frequency points (or intervals) should be specified In either case a desired signal level can be chosen

using the gain-control knob An oscillator that is operated exclusively in the sweep mode is called a sweep

oscillator

The early generation of oscillators employed variable inductor-capacitor types of electronic circuits to

generate signals oscillating at a desired frequency The oscillator is tuned to the required frequency by

varying the capacitance or inductance parameters A DC voltage is applied to energize the capacitor

and to obtain the desired oscillating voltage signal which subsequently is amplified and conditioned

Modern oscillators use operational amplifier circuits along with resistor capacitor and semiconductor

(SC) elements Also common are crystal (quartz) parallel-resonance oscillators used to generate voltage

signals accurately at a fixed frequency The circuit is activated using a DC-voltage source Other

frequencies of interest are obtained by passing this high-frequency signal through a frequency converter

The signal is then conditioned (amplified and filtered) Required shaping (for example rectangular

pulse) is obtained using a shape circuit Finally the required signal level is obtained by passing the

resulting signal through a variable-gain amplifier A block diagram of an oscillator illustrating various

stages in the generation of a periodic signal is given in Figure 113

A typical oscillator offers a choice of several (typically six) linear and logarithmic frequency ranges and

a sizable level of control capability (for example 80 dB) Upper and lower frequency limits in a sweep can

be preset on the front panel to any of the available frequency ranges Sweep-rate settings are continuously

DC Voltage

Oscillator

FrequencySpecification

FrequencyConverter

FilterAmplifier

ShaperPeriodicSignal

FrequencyCounter

Fixed-FrequencySignal

Variable-GainOutput

Amplifier

SignalSpecification

LevelSpecification

FIGURE 113 Block diagram of an oscillator-type signal generator

Vibration Monitoring Testing and Instrumentation1-18

53191mdash522007mdash1202mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

  • 53191fm
    • Vibration Monitoring Testing and Instrumentation
      • Preface
      • Acknowledgments
      • Editor-in-Chief
      • Contributors
      • Contents
      • Related Titles
          • 53191ch1
            • Table of Contents
            • Chapter 1 Vibration Instrumentation
              • Summary
              • 11 Introduction
              • 12 Vibration Exciters
                • 121 Shaker Selection
                  • 1211 Force Rating
                  • 1212 Power Rating
                  • 1213 Stroke Rating
                  • 1214 Hydraulic Shakers
                  • 1215 Inertial Shakers
                  • 1216 Electromagnetic Shakers
                    • 122 Dynamics of Electromagnetic Shakers
                      • 1221 Transient Exciters
                          • 13 Control System
                            • 131 Components of a Shaker Controller
                              • 1311 Compressor
                              • 1312 Equalizer (Spectrum Shaper)
                              • 1313 Tracking Filter
                              • 1314 Excitation Controller (Amplitude Servo-Monitor)
                                • 132 Signal-Generating Equipment
                                  • 1321 Oscillators
                                  • 1322 Random Signal Generators
                                  • 1323 Tape Players
                                  • 1324 Data Processing
                                      • 14 Performance Specification
                                        • 141 Parameters for Performance Specification
                                          • 1411 Time-Domain Specifications
                                          • 1412 Frequency-Domain Specifications
                                            • 142 Linearity
                                            • 143 Instrument Ratings
                                              • 1431 Rating Parameters
                                                • 144 Accuracy and Precision
                                                  • 15 Motion Sensors and Transducers
                                                    • 151 Potentiometer
                                                      • 1511 Potentiometer Resolution
                                                      • 1512 Optical Potentiometer
                                                        • 152 Variable-Inductance Transducers
                                                          • 1521 Mutual-Induction Transducers
                                                          • 1522 Linear-Variable Differential Transformer
                                                          • 1523 Signal Conditioning
                                                            • 153 Mutual-Induction Proximity Sensor
                                                            • 154 Selfinduction Transducers
                                                            • 155 Permanent-Magnet Transducers
                                                            • 156 Alternating Current Permanent-Magnet Tachometer
                                                            • 157 Alternating Current Induction Tachometer
                                                            • 158 Eddy Current Transducers
                                                            • 159 Variable-Capacitance Transducers
                                                              • 1591 Capacitive Displacement Sensors
                                                              • 1592 Capacitive Angular Velocity Sensor
                                                              • 1593 Capacitance Bridge Circuit
                                                                • 1510 Piezoelectric Transducers
                                                                  • 15101 Sensitivity
                                                                  • 15102 Piezoelectric Accelerometer
                                                                  • 15103 Charge Amplifier
                                                                      • 16 Torque Force and Other Sensors
                                                                        • 161 Strain Gage Sensors
                                                                          • 1611 Equations for Strain Gage Measurements
                                                                          • 1612 Bridge Sensitivity
                                                                          • 1613 The Bridge Constant
                                                                          • 1614 The Calibration Constant
                                                                          • 1615 Data Acquisition
                                                                          • 1616 Accuracy Considerations
                                                                          • 1617 Semiconductor Strain Gages
                                                                          • 1618 Force and Torque Sensors
                                                                          • 1619 Strain Gage Torque Sensors
                                                                          • 16110 Deflection Torque Sensors
                                                                          • 16111 Variable-Reluctance Torque Sensor
                                                                          • 16112 Reaction Torque Sensors
                                                                            • 162 Miscellaneous Sensors
                                                                              • 1621 Stroboscope
                                                                              • 1622 Fiber Optic Sensors and Lasers
                                                                              • 1623 Fiber-Optic Gyroscope
                                                                              • 1624 Laser Doppler Interferometer
                                                                              • 1625 Ultrasonic Sensors
                                                                              • 1626 Gyroscopic Sensors
                                                                                  • References
                                                                                  • Appendix 1A Virtual Instrumentation for Data Acquisition Analysis and Presentation
                                                                                    • Summary
                                                                                    • List of Abbreviations
                                                                                    • 1A1 Dynamic Signals
                                                                                      • 1A11 Acquiring and Simulating Dynamic Signals
                                                                                        • 1A111 Aliasing
                                                                                        • 1A112 Time Continuity
                                                                                            • 1A2 Measurement Configuration Considerations
                                                                                              • 1A21 Input Signal Considerations
                                                                                                • 1A211 Input Pseudodifferential and Differential Configuration
                                                                                                • 1A212 Gain
                                                                                                • 1A213 Input Coupling
                                                                                                • 1A214 Integrated Electronic Piezoelectric Excitation
                                                                                                • 1A215 Nyquist Frequency and Bandwidth
                                                                                                • 1A216 Analog-to-Digital Conversion
                                                                                                • 1A217 Antialias Filters
                                                                                                • 1A218 Input Filter Delay
                                                                                                • 1A219 Overload Detection
                                                                                                  • 1A22 Output Signal Considerations
                                                                                                    • 1A221 Output Pseudodifferential and Differential Configuration
                                                                                                    • 1A222 Attenuation
                                                                                                    • 1A223 Digital-to-Analog Conversion
                                                                                                    • 1A224 Anti-imaging and Interpolation Filters
                                                                                                    • 1A225 Output Filter Delay
                                                                                                        • 1A3 Scaling and Calibration
                                                                                                          • 1A31 Scaling to Engineering Units
                                                                                                          • 1A32 Performing System Calibration
                                                                                                            • 1A321 Propagation Delay Calibration
                                                                                                                • 1A4 Limit Testing Analysis
                                                                                                                  • 1A41 Limit Testing Overview
                                                                                                                  • 1A42 Using the SVT Limit Testing VI
                                                                                                                    • 1A5 Integration
                                                                                                                      • 1A51 Introduction to Integration
                                                                                                                      • 1A52 Implementing Integration
                                                                                                                        • 1A521 Challenges when Integrating Vibration Data
                                                                                                                          • 1A53 Time-Domain Integration
                                                                                                                            • 1A531 Single-Shot Acquisition and Integration
                                                                                                                            • 1A532 Continuous Acquisition and Integration
                                                                                                                              • 1A54 Frequency-Domain Integration
                                                                                                                                • 1A6 Vibration-Level Measurements
                                                                                                                                  • 1A61 Measuring the Root Mean Square Level
                                                                                                                                    • 1A611 Single-Shot Buffered Acquisition
                                                                                                                                    • 1A612 Continuous Signal Acquisition
                                                                                                                                      • 1A62 Performing a Running RMS Level Measurement
                                                                                                                                      • 1A63 Computing the Peak Level
                                                                                                                                      • 1A64 Computing the Crest Factor
                                                                                                                                        • 1A7 Frequency Analysis
                                                                                                                                          • 1A71 FFT Fundamentals
                                                                                                                                            • 1A711 Number of Samples
                                                                                                                                            • 1A712 Frequency Resolution
                                                                                                                                            • 1A713 Maximum Resolvable Frequency
                                                                                                                                            • 1A714 Minimum Resolvable Frequency
                                                                                                                                            • 1A715 Number of Spectral Lines
                                                                                                                                            • 1A716 Relationship between Time-Domain and Frequency-Domain Specifications and Parameters
                                                                                                                                              • 1A72 Increasing Frequency Resolution
                                                                                                                                                • 1A721 Zoom FFT Analysis
                                                                                                                                                • 1A722 Frequency Resolution of the Zoom FFT VIs
                                                                                                                                                • 1A723 Zoom Measurement
                                                                                                                                                • 1A724 Zoom Settings
                                                                                                                                                • 1A725 Subset Analysis
                                                                                                                                                    • 1A8 Transient Analysis
                                                                                                                                                      • 1A81 Transient Analysis with the Sound and Vibration Toolkit
                                                                                                                                                      • 1A82 Performing an STFT vs Time
                                                                                                                                                        • 1A821 Selecting the FFT Block Size
                                                                                                                                                        • 1A822 Overlapping
                                                                                                                                                        • 1A823 Using the SVT STFT vs Time VI
                                                                                                                                                          • 1A83 Performing an STFT vs Rotational Speed
                                                                                                                                                            • 1A831 Converting the Pulse Train to Rotational Speed
                                                                                                                                                            • 1A832 STFT vs RPM
                                                                                                                                                              • 1A84 Measuring a Shock Response Spectrum
                                                                                                                                                                • 1A9 Waterfall Display
                                                                                                                                                                  • 1A91 Using the Display VIs
                                                                                                                                                                    • 1A911 Initializing the Display
                                                                                                                                                                    • 1A912 Sending Data to the Display
                                                                                                                                                                    • 1A913 Waterfall Display for Frequency Analysis
                                                                                                                                                                    • 1A914 Waterfall Display for Transient Analysis
                                                                                                                                                                    • 1A915 Waterfall Display for Octave Spectra
                                                                                                                                                                        • 1A10 Swept-Sine Measurements
                                                                                                                                                                          • 1A101 Swept-Sine Overview
                                                                                                                                                                          • 1A102 Choosing Swept-Sine vs FFT Measurements
                                                                                                                                                                          • 1A103 Taking a Swept-Sine Measurement
                                                                                                                                                                          • 1A104 Swept-Sine Measurement Example
                                                                                                                                                                              • Bibliography
                                                                                                                                                                              • Related Titles
                                                                                                                                                                                  • 53191ch2
                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                    • Chapter 2 Signal Conditioning and Modification
                                                                                                                                                                                      • Summary
                                                                                                                                                                                      • 21 Introduction
                                                                                                                                                                                      • 22 Amplifiers
                                                                                                                                                                                        • 221 Operational Amplifier
                                                                                                                                                                                        • 222 Use of Feedback in Opamp
                                                                                                                                                                                        • 223 Voltage Current and Power Amplifiers
                                                                                                                                                                                          • 2231 Charge Amplifiers
                                                                                                                                                                                            • 224 Instrumentation Amplifiers
                                                                                                                                                                                              • 2241 Differential Amplifier
                                                                                                                                                                                              • 2242 Common Mode
                                                                                                                                                                                                • 225 Amplifier Performance Ratings
                                                                                                                                                                                                  • 2251 Common-Mode Rejection Ratio
                                                                                                                                                                                                    • 226 Component Interconnection
                                                                                                                                                                                                      • 2261 Impedance Characteristics
                                                                                                                                                                                                      • 2262 Cascade Connection of Devices
                                                                                                                                                                                                      • 2263 AC-Coupled Ampliers
                                                                                                                                                                                                          • 23 Analog Filters
                                                                                                                                                                                                            • 231 Passive Filters and Active Filters
                                                                                                                                                                                                              • 2311 Number of Poles
                                                                                                                                                                                                                • 232 Low-Pass Filters
                                                                                                                                                                                                                  • 2321 Low-Pass Butterworth Filter
                                                                                                                                                                                                                    • 233 High-Pass Filters
                                                                                                                                                                                                                    • 234 Band-Pass Filters
                                                                                                                                                                                                                      • 2341 Resonance-Type Band-Pass Filters
                                                                                                                                                                                                                        • 235 Band-Reject Filters
                                                                                                                                                                                                                          • 24 Modulators and Demodulators
                                                                                                                                                                                                                            • 241 Amplitude Modulation
                                                                                                                                                                                                                              • 2411 Modulation Theorem
                                                                                                                                                                                                                              • 2412 Side Frequencies and Side Bands
                                                                                                                                                                                                                                • 242 Application of Amplitude Modulation
                                                                                                                                                                                                                                  • 2421 Fault Detection and Diagnosis
                                                                                                                                                                                                                                    • 243 Demodulation
                                                                                                                                                                                                                                      • 25 Analog ndashDigital Conversion
                                                                                                                                                                                                                                        • 251 Digital-to-Analog Conversion
                                                                                                                                                                                                                                          • 2511 DAC Error Sources
                                                                                                                                                                                                                                            • 252 Analog-to-Digital Conversion
                                                                                                                                                                                                                                            • 253 Analog-to-Digital Converter Performance Characteristics
                                                                                                                                                                                                                                              • 2531 Resolution and Quantization Error
                                                                                                                                                                                                                                              • 2532 Monotonicity Nonlinearity and Offset Error
                                                                                                                                                                                                                                              • 2533 Analog-to-Digital Converter Conversion Rate
                                                                                                                                                                                                                                                • 254 Sample-and-Hold Circuitry
                                                                                                                                                                                                                                                • 255 Digital Filters
                                                                                                                                                                                                                                                  • 2551 Software Implementation and Hardware Implementation
                                                                                                                                                                                                                                                      • 26 Bridge Circuits
                                                                                                                                                                                                                                                        • 261 Wheatstone Bridge
                                                                                                                                                                                                                                                        • 262 Constant-Current Bridge
                                                                                                                                                                                                                                                        • 263 Bridge Amplifiers
                                                                                                                                                                                                                                                          • 2631 Half-Bridge Circuits
                                                                                                                                                                                                                                                            • 264 Impedance Bridges
                                                                                                                                                                                                                                                              • 2641 Owen Bridge
                                                                                                                                                                                                                                                              • 2642 Wien-Bridge Oscillator
                                                                                                                                                                                                                                                                  • 27 Linearizing Devices
                                                                                                                                                                                                                                                                    • 271 Linearization by Software
                                                                                                                                                                                                                                                                    • 272 Linearization by Hardware Logic
                                                                                                                                                                                                                                                                    • 273 Analog Linearizing Circuitry
                                                                                                                                                                                                                                                                    • 274 Offsetting Circuitry
                                                                                                                                                                                                                                                                    • 275 Proportional-Output Circuitry
                                                                                                                                                                                                                                                                      • 2751 Curve-Shaping Circuitry
                                                                                                                                                                                                                                                                          • 28 Miscellaneous Signal Modification Circuitry
                                                                                                                                                                                                                                                                            • 281 Phase Shifters
                                                                                                                                                                                                                                                                            • 282 Voltage-to-Frequency Converter
                                                                                                                                                                                                                                                                            • 283 Frequency-to-Voltage Converter
                                                                                                                                                                                                                                                                            • 284 Voltage-to-Current Converters
                                                                                                                                                                                                                                                                            • 285 Peak-Hold Circuits
                                                                                                                                                                                                                                                                              • 29 Signal Analyzers and Display Devices
                                                                                                                                                                                                                                                                                • 291 Signal Analyzers
                                                                                                                                                                                                                                                                                • 292 Oscilloscopes
                                                                                                                                                                                                                                                                                  • 2921 Triggering
                                                                                                                                                                                                                                                                                  • 2922 Lissajous Patterns
                                                                                                                                                                                                                                                                                  • 2923 Digital Oscilloscopes
                                                                                                                                                                                                                                                                                      • Bibliography
                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                          • 53191ch3
                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                            • Chapter 3 Vibration Testing
                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                              • 31 Introduction
                                                                                                                                                                                                                                                                                              • 32 Representation of a Vibration Environment
                                                                                                                                                                                                                                                                                                • 321 Test Signals
                                                                                                                                                                                                                                                                                                  • 3211 Stochastic vs Deterministic Signals
                                                                                                                                                                                                                                                                                                    • 322 Deterministic Signal Representation
                                                                                                                                                                                                                                                                                                      • 3221 Single-Frequency Signals
                                                                                                                                                                                                                                                                                                      • 3222 Sine Sweep
                                                                                                                                                                                                                                                                                                      • 3223 Sine Dwell
                                                                                                                                                                                                                                                                                                      • 3224 Decaying Sine
                                                                                                                                                                                                                                                                                                      • 3225 Sine Beat
                                                                                                                                                                                                                                                                                                      • 3226 Sine Beat with Pauses
                                                                                                                                                                                                                                                                                                      • 3227 Multifrequency Signals
                                                                                                                                                                                                                                                                                                      • 3228 Actual Excitation Records
                                                                                                                                                                                                                                                                                                      • 3229 Simulated Excitation Signals
                                                                                                                                                                                                                                                                                                        • 323 Stochastic Signal Representation
                                                                                                                                                                                                                                                                                                          • 3231 Ergodic Random Signals
                                                                                                                                                                                                                                                                                                          • 3232 Stationary Random Signals
                                                                                                                                                                                                                                                                                                          • 3233 Independent and Uncorrelated Signals
                                                                                                                                                                                                                                                                                                          • 3234 Transmission of Random Excitations
                                                                                                                                                                                                                                                                                                            • 324 Frequency-Domain Representations
                                                                                                                                                                                                                                                                                                              • 3241 Fourier Spectrum Method
                                                                                                                                                                                                                                                                                                              • 3242 Power Spectral Density Method
                                                                                                                                                                                                                                                                                                                • 325 Response Spectrum
                                                                                                                                                                                                                                                                                                                  • 3251 Displacement Velocity and Acceleration Spectra
                                                                                                                                                                                                                                                                                                                  • 3252 Response-Spectra Plotting Paper
                                                                                                                                                                                                                                                                                                                  • 3253 Zero-Period Acceleration
                                                                                                                                                                                                                                                                                                                  • 3254 Uses of Response Spectra
                                                                                                                                                                                                                                                                                                                    • 326 Comparison of Various Representations
                                                                                                                                                                                                                                                                                                                      • 33 Pretest Procedures
                                                                                                                                                                                                                                                                                                                        • 331 Purpose of Testing
                                                                                                                                                                                                                                                                                                                        • 332 Service Functions
                                                                                                                                                                                                                                                                                                                          • 3321 Active Equipment
                                                                                                                                                                                                                                                                                                                          • 3322 Passive Equipment
                                                                                                                                                                                                                                                                                                                          • 3323 Functional Testing
                                                                                                                                                                                                                                                                                                                            • 333 Information Acquisition
                                                                                                                                                                                                                                                                                                                              • 3331 Interface Details
                                                                                                                                                                                                                                                                                                                              • 3332 Effect of Neglecting Interface Dynamics
                                                                                                                                                                                                                                                                                                                              • 3333 Effects of Damping
                                                                                                                                                                                                                                                                                                                              • 3334 Effects of Inertia
                                                                                                                                                                                                                                                                                                                              • 3335 Effect of Natural Frequency
                                                                                                                                                                                                                                                                                                                              • 3336 Effect of Excitation Frequency
                                                                                                                                                                                                                                                                                                                              • 3337 Other Effects of Interface
                                                                                                                                                                                                                                                                                                                                • 334 Test-Program Planning
                                                                                                                                                                                                                                                                                                                                  • 3341 Testing of Cabinet-Mounted Equipment
                                                                                                                                                                                                                                                                                                                                    • 335 Pretest Inspection
                                                                                                                                                                                                                                                                                                                                      • 34 Testing Procedures
                                                                                                                                                                                                                                                                                                                                        • 341 Resonance Search
                                                                                                                                                                                                                                                                                                                                        • 342 Methods of Determining Frequency-Response Functions
                                                                                                                                                                                                                                                                                                                                          • 3421 Fourier Transform Method
                                                                                                                                                                                                                                                                                                                                          • 3422 Spectral Density Method
                                                                                                                                                                                                                                                                                                                                          • 3423 Harmonic Excitation Method
                                                                                                                                                                                                                                                                                                                                            • 343 Resonance-Search Test Methods
                                                                                                                                                                                                                                                                                                                                              • 3431 Hammer (Bump) Test and Drop Test
                                                                                                                                                                                                                                                                                                                                              • 3432 Pluck Test
                                                                                                                                                                                                                                                                                                                                              • 3433 Shaker Tests
                                                                                                                                                                                                                                                                                                                                                • 344 Mechanical Aging
                                                                                                                                                                                                                                                                                                                                                  • 3441 Equivalence for Mechanical Aging
                                                                                                                                                                                                                                                                                                                                                  • 3442 Excitation-Intensity Equivalence
                                                                                                                                                                                                                                                                                                                                                  • 3443 Dynamic-Excitation Equivalence
                                                                                                                                                                                                                                                                                                                                                  • 3444 Cumulative Damage Theory
                                                                                                                                                                                                                                                                                                                                                    • 345 Test-Response Spectrum Generation
                                                                                                                                                                                                                                                                                                                                                    • 346 Instrument Calibration
                                                                                                                                                                                                                                                                                                                                                    • 347 Test-Object Mounting
                                                                                                                                                                                                                                                                                                                                                    • 348 Test-Input Considerations
                                                                                                                                                                                                                                                                                                                                                      • 3481 Test Nomenclature
                                                                                                                                                                                                                                                                                                                                                      • 3482 Testing with Uncorrelated Excitations
                                                                                                                                                                                                                                                                                                                                                      • 3483 Symmetrical Rectilinear Testing
                                                                                                                                                                                                                                                                                                                                                      • 3484 Geometry vs Dynamics
                                                                                                                                                                                                                                                                                                                                                      • 3485 Some Limitations
                                                                                                                                                                                                                                                                                                                                                      • 3486 Testing Black Boxes
                                                                                                                                                                                                                                                                                                                                                      • 3487 Phasing of Excitations
                                                                                                                                                                                                                                                                                                                                                      • 3488 Testing a Gray or White Box
                                                                                                                                                                                                                                                                                                                                                      • 3489 Overtesting in Multitest Sequences
                                                                                                                                                                                                                                                                                                                                                          • 35 Some Practical Information
                                                                                                                                                                                                                                                                                                                                                            • 351 Random Vibration Test Example
                                                                                                                                                                                                                                                                                                                                                            • 352 Vibration Shakers and Control Systems
                                                                                                                                                                                                                                                                                                                                                              • Bibliography
                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                  • 53191ch4
                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                    • Chapter 4 Experimental Modal Analysis
                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                      • 41 Introduction
                                                                                                                                                                                                                                                                                                                                                                      • 42 Frequency-Domain Formulation
                                                                                                                                                                                                                                                                                                                                                                        • 421 Transfer-Function Matrix
                                                                                                                                                                                                                                                                                                                                                                        • 422 Principle of Reciprocity
                                                                                                                                                                                                                                                                                                                                                                          • 43 Experimental Model Development
                                                                                                                                                                                                                                                                                                                                                                            • 431 Extraction of the Time-Domain Model
                                                                                                                                                                                                                                                                                                                                                                              • 44 Curve Fitting of Transfer Functions
                                                                                                                                                                                                                                                                                                                                                                                • 441 Problem Identification
                                                                                                                                                                                                                                                                                                                                                                                • 442 Single- and Multi-Degree-of-Freedom Techniques
                                                                                                                                                                                                                                                                                                                                                                                • 443 Single-Degree-of-Freedom Parameter Extraction in the Frequency Domain
                                                                                                                                                                                                                                                                                                                                                                                  • 4431 Circle-Fit Method
                                                                                                                                                                                                                                                                                                                                                                                    • Case of Viscous Damping
                                                                                                                                                                                                                                                                                                                                                                                    • Case of Hysteretic Damping
                                                                                                                                                                                                                                                                                                                                                                                      • 4432 Peak-Picking Method
                                                                                                                                                                                                                                                                                                                                                                                        • 444 Multi-Degree of Freedom Curve Fitting
                                                                                                                                                                                                                                                                                                                                                                                          • 4441 Formulation of the Method
                                                                                                                                                                                                                                                                                                                                                                                            • 445 A Comment on Static Modes and Rigid-Body Modes
                                                                                                                                                                                                                                                                                                                                                                                            • 446 Residue Extraction
                                                                                                                                                                                                                                                                                                                                                                                              • 45 Laboratory Experiments
                                                                                                                                                                                                                                                                                                                                                                                                • 451 Lumped-Parameter System
                                                                                                                                                                                                                                                                                                                                                                                                  • 4511 Frequency-Domain Test
                                                                                                                                                                                                                                                                                                                                                                                                  • 4512 Time-Domain Tests
                                                                                                                                                                                                                                                                                                                                                                                                    • 452 Distributed-Parameter System
                                                                                                                                                                                                                                                                                                                                                                                                      • 46 Commercial EMA Systems
                                                                                                                                                                                                                                                                                                                                                                                                        • 461 System Configuration
                                                                                                                                                                                                                                                                                                                                                                                                          • 4611 FFT Analysis Options
                                                                                                                                                                                                                                                                                                                                                                                                          • 4612 Modal Analysis Components
                                                                                                                                                                                                                                                                                                                                                                                                              • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                  • 53191ch5
                                                                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                    • Chapter 5 Mechanical Shock
                                                                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                      • 51 Definitions
                                                                                                                                                                                                                                                                                                                                                                                                                        • 511 Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 512 Simple (or Perfect) Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 513 Half-Sine Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 514 Versed-Sine (or Haversine) Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 515 Terminal Peak Sawtooth Shock or Final Peak Sawtooth Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 516 Rectangular Shock
                                                                                                                                                                                                                                                                                                                                                                                                                          • 5161 Trapezoidal Shock
                                                                                                                                                                                                                                                                                                                                                                                                                              • 52 Description in the Time Domain
                                                                                                                                                                                                                                                                                                                                                                                                                              • 53 Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                • 531 Need
                                                                                                                                                                                                                                                                                                                                                                                                                                • 532 Shock Response Spectrum Definition
                                                                                                                                                                                                                                                                                                                                                                                                                                • 533 Response of a Linear One-Degree-of-Freedom System
                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5331 Shock Defined by a Force
                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5332 Shock Defined by an Acceleration
                                                                                                                                                                                                                                                                                                                                                                                                                                    • 534 Definitions
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5341 Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5342 Absolute Acceleration Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5343 Relative Displacement Shock Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5344 Primary Positive Shock Response Spectrum or Initial Positive Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5345 Primary (or Initial) Negative Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5346 Secondary (or Residual) Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5347 Positive (or Maximum Positive) Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5348 Negative (or Maximum Negative) Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5349 Maximax Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53410 Choice of Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                        • 535 Standardized Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5351 Definition
                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5352 Standardized Shock Response Spectra of Simple Shocks
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53521 Half-Sine Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53522 Versed Sine Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53523 Terminal Peak Sawtooth Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53524 Rectangular Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53525 Trapezoidal Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 536 Choice of Damping
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 537 Shock Response Spectra Domains
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 538 Algorithms for Calculation of the Shock Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 539 Choice of the Digitization Frequency of the Signal
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5310 Use of Shock Response Spectra for the Study of Systems with Several Degrees of Freedom
                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 54 Pyroshocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 55 Use of Shock Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 551 Severity Comparison of Several Shocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 552 Test Specification Development from Real Environment Data
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5521 Synthesis of Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5522 Nature of the Specification
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5523 Choice of Shape
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5524 Amplitude
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5525 Duration
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5526 Difficulties
                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 56 Standards
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 561 Types of Standards
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 562 Installation Conditions of Test Item
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 563 Uncertainty Factor
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 564 Bump Test
                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 57 Damage Boundary Curve
                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 571 Definition
                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 572 Analysis of Test Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 58 Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 581 Main Types
                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 582 Impact Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5821 Universal Shock-Test Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 58211 Impact Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 58212 Impulse Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 583 Shock Simulators (Programmers)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5831 Half-Sine Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58311 Shock Duration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58312 Impact Velocity
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58313 Maximum Deformation of the Shock Simulator (Programmer)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58314 Shock Amplitude
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58315 Characteristics of the Target
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5832 Terminal Peak Sawtooth Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5833 Rectangular Pulse ndash Trapezoidal Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5834 Universal Shock Simulator (Programmer)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 58341 Generating a Half-Sine Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 58342 Generating a Terminal Peak Sawtooth Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 58343 Trapezoidal Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 584 Limitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5841 Limitations of the Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5842 Limitations of Shock Simulators
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 585 Pneumatic Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 586 High Impact Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5861 Lightweight High Impact Shock Machine
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5862 Medium Weight High Impact Shock Machine
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 587 Specific Test Facilities
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 59 Generation of Shock Using Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 591 Principle Behind the Generation of a Simple Shape Signal versus Time
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 592 Main Advantages
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 593 Pre- and Postshocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5931 Requirements
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5932 Solutions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 59321 Optimized Pre- and Postpulses
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5933 Incidence on the Shock Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 594 Limitations of Electrodynamic Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5941 Mechanical Limitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 59411 Abacuses
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5942 Electronic Limitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 595 The Use of Electrohydraulic Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 510 Control by a Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 5101 Principle
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 5102 Principal Shapes of Elementary Signals
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 51021 Decaying Sinusoid
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 51022 ZERD Function
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 51023 WAVSIN Waveform
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 5103 Comparison of WAVSIN SHOC Waveforms and Decaying Sinusoid
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 5104 Criticism of Control by a Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 511 Pyrotechnic Shock Simulation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5111 Simulation Using Pyrotechnic Facilities
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5112 Simulation Using Metal-to-Metal Impact
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5113 Simulation Using Electrodynamic Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5114 Simulation Using Conventional Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53191ch6
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Chapter 6 Machine Condition Monitoring and Fault Diagnostics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 61 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 62 Machinery Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 621 Causes of Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 622 Types of Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 623 Frequency of Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 63 Basic Maintenance Strategies
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 631 Run-to-Failure (Breakdown) Maintenance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 632 Scheduled (Preventative) Maintenance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 633 Condition-Based (Predictive Proactive Reliability Centered On-Condition) Maintenance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 64 Factors Which Influence Maintenance Strategy
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 65 Machine Condition Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 651 Periodic Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 652 Continuous Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 66 Transducer Selection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 661 Noncontact Displacement Transducers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 662 Velocity Transducers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 663 Acceleration Transducers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 67 Transducer Location
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 68 Recording and Analysis Instrumentation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 681 Vibration Meters
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 682 Data Collectors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 683 Frequency-Domain Analyzers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 684 Time-Domain Instruments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 685 Tracking Analyzers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 69 Display Formats and Analysis Tools
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 691 Time Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6911 Time-Waveform Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6912 Time-Waveform Indices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6913 Time-Synchronous Averaging
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6914 Negative Averaging
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6915 Orbits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6916 Probability Density Functions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6917 Probability Density Moments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 692 Frequency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6921 Band-Pass Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6922 Shock Pulse (Spike Energy)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6923 Enveloped Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6924 Signature Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6925 Cascades (Waterfall Plots)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6926 Masks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6927 Frequency-Domain Indices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 693 Modal Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 694 Quefrency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 610 Fault Detection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 6101 Standards
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61011 Standards Based on Machinery Type
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61012 Standards Based on Vibration Severity
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 6102 Acceptance Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 61021 Statistical Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 6103 Frequency-Domain Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61031 Limited Band Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61032 Constant Bandwidth Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61033 Constant Percentage Bandwidth Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 611 Fault Diagnostics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 6111 Forcing Functions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61111 Unbalance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61112 Misalignment
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61113 Mechanical Looseness
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61114 Soft Foot
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61115 Rubs
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61116 Resonances
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61117 Oil Whirl
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61118 Oil Whip
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61119 Structural Vibrations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 611110 Foundation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 6112 Specific Machine Components
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 61121 Damaged or Worn Rolling-Element Bearings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 61122 Damaged or Worn Gears
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 6113 Specific Machine Types
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61131 Pumps
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61132 Fans
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61133 Electric Motors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61134 Steam and Gas Turbines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61135 Compressors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61136 Reciprocating Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 6114 Advanced Fault Diagnostic Techniques
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 53191ch7
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • Chapter 7 Vibration-Based Tool Condition Monitoring Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 71 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 72 Mechanics of Turning
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 721 General Terms
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 722 Chatter Vibrations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 723 Tool Wear
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7231 Tool Failure Mechanisms
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7232 Tool Failure Modes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7233 Tool Wear Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7234 Tool Wear Stages
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 73 Vibration Signal Recording
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 731 Direct and Indirect Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 732 Sensor Requirements for Tool Wear Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 733 Force Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7331 Direct Measurement Dynamometers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7332 Indirect Force Sensors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7333 Piezoelectric Strain Sensors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7334 Resistance Strain Gauges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7335 Customized Force Sensors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 734 Acceleration Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 735 Acoustic Emission Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 736 Sensor Comparisons
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 74 Signal Processing for Sensor-Based Tool Condition Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 741 Feature Extraction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7411 Time Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7412 Frequency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7413 Statistical Processing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7414 TimendashFrequency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 742 Feature Selection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 75 Wear ModelDecision-Making for Sensor-Based Tool Condition Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 751 Trending Threshold
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 752 Neural Networks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7521 Unsupervised Networks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7522 Supervised Networks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 753 Fuzzy Logic
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 754 Other Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 76 Conclusion
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53191ch8
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Chapter 8 Fault Diagnosis of Helicopter Gearboxes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 81 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 82 Abnormality Scaling
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 83 The Structure-Based Connectionist Network
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 84 Sensor Location Selection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 841 Coverage Index
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 842 Overlap Index
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 843 Monitoring Effectiveness
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 85 A Case Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 851 Structural and Featural Influences
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 852 Evaluation of Influences
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 853 Fault Detection Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 854 Fault Diagnostic Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 8541 Faulty Subsystem Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 8542 Faulty Component Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 855 Sensor Location Evaluation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 856 Sensor Location Validation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 86 Conclusion
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 53191ch9
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Chapter 9 Vibration Suppression and Monitoring in Precision Motion Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 91 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 92 Mechanical Design to Minimize Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 921 Stability and Static Determinacy of Machine Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 922 Two-Dimensional Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 923 Three-Dimensional Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 93 Adaptive Notch Filter
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 931 Fast Fourier Transform
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 932 Simulation and Experiments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 94 Real-Time Vibration Analyzer
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 941 Learning Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 942 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 943 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 944 Experiments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 9441 Input Variables mdash the Evaluation Criteria
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 94411 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 94412 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 9442 Evaluation Rules
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 94421 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 94422 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 9443 Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 94431 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 94432 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 95 Practical Insights and Case Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 96 Conclusions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 53191ch10
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Chapter 10 Vibration and Shock Problems of Civil Engineering Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 101 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 102 Earthquake-Induced Vibration of Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1021 Seismicity and Ground Motions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1022 Influence of Local Site Conditions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1023 Response of Structures to Ground Motions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1024 Dynamic Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10241 Equations of Motion for Linear Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10242 Equations of Motion for Linear Multiple-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1025 Earthquake Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10251 Elastic Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10252 Smoothed Design Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10253 Ductility-Modified Response Spectrum Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1026 Design Philosophy and the Code Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10261 Performance-Based Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1027 Analysis Options for Earthquake Effects
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10271 Dynamic Time History Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10272 Response Spectrum Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 102721 Response Spectrum Analysis of Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 102722 Response Spectrum Analysis of Multi-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10273 Equivalent Static Analysis (Force-Based Approach)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10274 Displacement-Based Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1028 SoilndashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1029 Active and Passive Control Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 10210 Worked Examples
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 103 Dynamic Effects of Wind Loading on Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1031 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1032 Wind Speed
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1033 Design Structures for Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10331 Types of Wind Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10332 Design Criteria
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10333 Static Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1034 Along and Across-Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10341 Along-Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10342 Across-Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1035 Wind Tunnel Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1036 Comfort Criteria Human Response to Building Motion
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1037 Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1038 Comparison with Earthquake Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 104 Vibrations Due to Fluid ndashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1041 Added Mass and Inertial Coupling
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1042 Wave-Induced Vibration of Structure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 105 Blast Loading and Blast Effects on Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1051 Explosions and Blast Phenomenon
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1052 Explosive Air-Blast Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10521 Blast Wave Scaling Laws
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10522 Prediction of Blast Pressure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1053 Gas Explosion Loading and Effect of Internal Explosions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1054 Structural Response to Blast Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10541 Elastic Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10542 Elasto-Plastic Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1055 Material Behaviors at High Strain Rate
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10551 Dynamic Properties of Concrete under High Strain Rates
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10552 Dynamic Properties of Reinforcing Steel under High Strain Rates
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1056 Failure Modes of Blast-Loaded Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10561 Global Structural Behavior
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10562 Localized Structural Behavior
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10563 PressurendashImpulse ( PndashI ) Diagrams
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1057 Blast WavendashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1058 Effect of Ground Shocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10581 Loads from Air-Induced Ground Shock
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10582 Loads from Direct Ground Shock
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1059 Technical Design Manuals for Blast-Resistant Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 10510 Computer Programs for Blast and Shock Effects
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 106 Impact Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1061 Structural Impact between Two Bodies mdash Hard Impact and Soft Impact
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1062 Example mdash Aircraft Impact
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 107 Floor Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1071 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1072 Types of Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10721 Walking
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10722 Rhythmic Activities
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10723 Mechanical Equipment
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10724 Analysis Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1073 Natural Frequency of Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10731 Computing the Natural Frequency
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10732 Computing Deflection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10733 Damping
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10734 Resonance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1074 Vibration Caused by Walking
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10741 Minimum Natural Frequency
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1075 Design for Rhythmic Excitation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10751 Harmonics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10752 Minimum Natural Frequency
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1076 Example mdash Vibration Analysis of a Reinforced Concrete Floor
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 53191ch11
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Chapter 11 Seismic Base Isolation and Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 111 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1111 From Ductility Design to Base Isolation and Control Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1112 The Importance of Reducing Seismic Input and Response
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 112 Seismic Base Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1121 Historical Development of Base Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1122 Basic Principle
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1123 Issues in Seismic Base Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11231 Performance Criteria
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11232 Type of Structure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11233 Site Characteristics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11234 Retrofit Issues
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11235 Design of Building Services
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11236 Expected Life of Isolator
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1124 Seismic Isolation Devices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11241 Laminated Rubber Bearings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11242 Lead Rubber Bearing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11243 Friction-Based Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11244 Other Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1125 Design of Isolation Devices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11251 High-Damping Rubber Bearing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112511 Stability against Buckling
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112512 Stability against Roll Out
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11252 Lead Rubber Bearings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112521 Design of Lead Plug
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112522 Design of Laminated Rubber Bearing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11253 Design of Friction Pendulum System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1126 Verification of Properties of Isolation Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11261 Tests for Isolation Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 112611 System Characterization Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 112612 Prototype Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 112613 Quality Control Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11262 Uniform Building Code Recommendations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112621 Units Dependent on Loading Rates
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112622 Units Dependent on Bilateral Load
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112623 System Adequacy
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1127 Analysis of Base-Isolated Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11271 Modeling of a Superstructure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11272 Modeling of Isolation System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11273 Static Analysis Procedure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11274 Dynamic Analysis Procedure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 112741 Response Spectrum Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 112742 Time-History Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11275 Software for Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1128 Experimental Methods for Isolated Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1129 Implementation of Seismic Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11291 New Construction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112911 Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112912 Bridges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11292 Seismic Retrofit
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112921 Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112922 Bridges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11293 Other Implementations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 11210 Performance during Past Earthquakes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 112101 Performance of Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 112102 Performance of Bridges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 113 Seismic Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1131 Historical Development of Seismic Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1132 Basic Principles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11321 Passive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11322 Active Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11323 Semiactive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11324 Hybrid Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11325 Categorization of Basic Principles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1133 Important Issues in Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11331 SoilndashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11332 DevicendashStructure Interaction and Time Delay
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11333 Design Guidelines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1134 Vibration-Control Devices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11341 Passive Control Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113411 Metallic Yielding Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113412 Friction Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113413 Viscoelastic Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113414 Viscous Fluid Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113415 Tuned Mass Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11342 Active Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113421 Electromagnetic Actuator
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113422 Hydraulic Actuators
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11343 Semiactive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113431 Variable-Orifice Hydraulic Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113432 Controllable Fluid Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113433 Controllable Friction Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11344 Hybrid Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1135 Control Algorithm
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11351 Active Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11352 Semiactive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113521 Common Control Schemes for Controllable Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113522 Special Control Schemes for Controllable Damper
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1136 Experimental Performance Verification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11361 Shaking Table Tests of a Flexible Structural Model with TMD AMD and ATMD
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11362 Substructure Hybrid Test
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113621 Hybrid Tests Using Hydraulic Actuator
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113622 Hybrid Tests Using Shaking Table
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113623 Hybrid Tests Using Inertia-Force-Driven Loading System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1137 Implementations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11371 Semiactive Control of Full-Scale Structures Using Variable Joint Damper System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113711 Background of Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113712 Test System Set Up
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113713 Control Algorithm
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113714 Test Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11372 Application of Structural Control Technologies to Seismic Retrofit of a Cable-Stayed Bridge
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113721 Background of Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113722 Basic Concept of Seismic Retrofit
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113723 Modal Shape Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113724 Time-History Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113725 Soil ndash Structure Interaction Effect
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113726 Semiactive Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53191ch12
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Chapter 12 Seismic Random Vibration of Long-Span Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 121 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1211 Basic Concepts of Random Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12111 Stationary Random Process
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12112 Nonstationary Random Process
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1212 Three Methods for Structural Seismic Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12121 Response Spectrum Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12122 Time-History Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12123 Random Vibration Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 121231 Davenport Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 121232 Vanmarcke Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 12124 Comparisons of the Three Seismic-Analysis Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 122 Seismic Random-Excitation Fields
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1221 Power Spectral Density of Spatially Varying Ground Acceleration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1222 Several Coherence Models
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12221 FengndashHu Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12222 Harichandran ndashVanmarcke Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12223 LohndashYeh Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12224 OliveirandashHaondashPenzien Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12225 LucondashWong Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12226 QundashWangndashWang Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1223 Generation of Ground Acceleration Power Spectral Density Curves from Acceleration Response Spectrum Curves
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12231 Kaul Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12232 Iteration Scheme
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1224 Seismic Equations of Motion of Long-Span Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1225 Seismic Waves and Their Geometrical Expressions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 123 Pseudoexcitation Method for Structural Random Vibration Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1231 Structures Subjected to Stationary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12311 Single Stationary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12312 Multiple Stationary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1232 Structures Subjected to Nonstationary Random Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12321 Structures Subjected to Uniformly Modulated Evolutionary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 123211 Single Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 123212 Multiple Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12322 Structures Subjected to Nonuniformly Modulated Evolutionary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 123221 Single Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 123222 Multiple Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1233 Precise Integration Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12331 Precise Integration of Exponential Matrices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12332 Particular Solutions and Precise Integration Formulas for Various Forms of Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 123321 Linear Loading Form (HPD-L Form)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 123322 Sinusoidal Loading Form (HPD-S Form)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 123323 Exponentially Decaying Sinusoidal Loading Form (HPD-E Form)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 124 Long-Span Structures Subjected to Stationary Random Ground Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1241 The Solution of Equations of Motion Using the Pseudoexcitation Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1242 Numerical Comparisons with Other Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12421 Song-Hua-Jiang Suspension Bridge
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 124211 All Supports Move Uniformly
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 124212 Wave Passage Effect Is Taken into Account
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 124213 Wave-Passage Effect and Incoherence Effect Are Jointly Taken into Account
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 12422 San Joaquin Concrete Bridge
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 125 Long-Span Structures Subjected to Nonstationary Random Ground Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1251 Modulation Functions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1252 The Formulas for Nonstationary Multiexcitation Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1253 Expected Extreme Values of Nonstationary Random Processes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1254 Numerical Comparisons with the Corresponding Stationary Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 126 Conclusions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 53191ch13
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Chapter 13 Seismic Qualification of Equipment
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 131 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 132 Distribution Qualification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1321 Drive-Signal Generation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1322 Distribution Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1323 Test Procedures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 133 Seismic Qualification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1331 Stages of Seismic Qualification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1332 Test Preliminaries
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1333 Single-Frequency Testing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1334 Multifrequency Testing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1335 Generation of RRS Specifications
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 53191ch14
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Chapter 14 Human Response to Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 141 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 142 Vibration Excitations on Humans
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1421 Excitation Characteristics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 143 Human Response to Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1431 Vibration Perception
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1432 Frequency Weighting Curve
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1433 Iso-Perception Curves
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1434 Detection Threshold Curve
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 144 Regulation of Human Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1441 Acceptable Vibration Levels in Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1442 Whole-Body Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1443 HandndashArm Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
Page 30: Vibration Monitoring, Testing, and Instrumentationpreview.kingborn.net › 646000 › d1a74678d91943e5ba1d5e... · The MEMS Handbook, Second Edition MEMS: Introduction and Fundamentals

discuss these two generators separately however because of their difference in function It also should be

noted that almost any digital signal (deterministic or random) can be generated by a digital computer

using a suitable computer program the signal eventually can be passed through a DAC to obtain

the corresponding analog signal These lsquodigitalrsquo signal generators along with analog sources such as

magnetic tape players (FM) are classified into the category of storage devices

The dynamic range of equipment is the ratio of the maximum and minimum output levels (expressed

in decibels) at which it is capable of operating without significant error This is an important specification

for many types of equipment particularly for signal-generating devices The output level of the signal

generator should be set to a value within its dynamic range

1321 Oscillators

Oscillators are essentially single-frequency generators Typically sine signals are generated but other

waveforms (such as rectangular and triangular pulses) are also available in most oscillators Normally

an oscillator has two modes of operation (1) sweeping up and down between two frequency limits and

(2) dwelling at a specified frequency In the sweep operation the sweep rate should be specified This can

be done either on a linear scale (Hzmin) or on a logarithmic scale (octavesmin) In the dwell operation

the frequency points (or intervals) should be specified In either case a desired signal level can be chosen

using the gain-control knob An oscillator that is operated exclusively in the sweep mode is called a sweep

oscillator

The early generation of oscillators employed variable inductor-capacitor types of electronic circuits to

generate signals oscillating at a desired frequency The oscillator is tuned to the required frequency by

varying the capacitance or inductance parameters A DC voltage is applied to energize the capacitor

and to obtain the desired oscillating voltage signal which subsequently is amplified and conditioned

Modern oscillators use operational amplifier circuits along with resistor capacitor and semiconductor

(SC) elements Also common are crystal (quartz) parallel-resonance oscillators used to generate voltage

signals accurately at a fixed frequency The circuit is activated using a DC-voltage source Other

frequencies of interest are obtained by passing this high-frequency signal through a frequency converter

The signal is then conditioned (amplified and filtered) Required shaping (for example rectangular

pulse) is obtained using a shape circuit Finally the required signal level is obtained by passing the

resulting signal through a variable-gain amplifier A block diagram of an oscillator illustrating various

stages in the generation of a periodic signal is given in Figure 113

A typical oscillator offers a choice of several (typically six) linear and logarithmic frequency ranges and

a sizable level of control capability (for example 80 dB) Upper and lower frequency limits in a sweep can

be preset on the front panel to any of the available frequency ranges Sweep-rate settings are continuously

DC Voltage

Oscillator

FrequencySpecification

FrequencyConverter

FilterAmplifier

ShaperPeriodicSignal

FrequencyCounter

Fixed-FrequencySignal

Variable-GainOutput

Amplifier

SignalSpecification

LevelSpecification

FIGURE 113 Block diagram of an oscillator-type signal generator

Vibration Monitoring Testing and Instrumentation1-18

53191mdash522007mdash1202mdashSENTHILKUMARmdash246494mdash CRC ndash pp 1ndash112

copy 2007 by Taylor amp Francis Group LLC

  • 53191fm
    • Vibration Monitoring Testing and Instrumentation
      • Preface
      • Acknowledgments
      • Editor-in-Chief
      • Contributors
      • Contents
      • Related Titles
          • 53191ch1
            • Table of Contents
            • Chapter 1 Vibration Instrumentation
              • Summary
              • 11 Introduction
              • 12 Vibration Exciters
                • 121 Shaker Selection
                  • 1211 Force Rating
                  • 1212 Power Rating
                  • 1213 Stroke Rating
                  • 1214 Hydraulic Shakers
                  • 1215 Inertial Shakers
                  • 1216 Electromagnetic Shakers
                    • 122 Dynamics of Electromagnetic Shakers
                      • 1221 Transient Exciters
                          • 13 Control System
                            • 131 Components of a Shaker Controller
                              • 1311 Compressor
                              • 1312 Equalizer (Spectrum Shaper)
                              • 1313 Tracking Filter
                              • 1314 Excitation Controller (Amplitude Servo-Monitor)
                                • 132 Signal-Generating Equipment
                                  • 1321 Oscillators
                                  • 1322 Random Signal Generators
                                  • 1323 Tape Players
                                  • 1324 Data Processing
                                      • 14 Performance Specification
                                        • 141 Parameters for Performance Specification
                                          • 1411 Time-Domain Specifications
                                          • 1412 Frequency-Domain Specifications
                                            • 142 Linearity
                                            • 143 Instrument Ratings
                                              • 1431 Rating Parameters
                                                • 144 Accuracy and Precision
                                                  • 15 Motion Sensors and Transducers
                                                    • 151 Potentiometer
                                                      • 1511 Potentiometer Resolution
                                                      • 1512 Optical Potentiometer
                                                        • 152 Variable-Inductance Transducers
                                                          • 1521 Mutual-Induction Transducers
                                                          • 1522 Linear-Variable Differential Transformer
                                                          • 1523 Signal Conditioning
                                                            • 153 Mutual-Induction Proximity Sensor
                                                            • 154 Selfinduction Transducers
                                                            • 155 Permanent-Magnet Transducers
                                                            • 156 Alternating Current Permanent-Magnet Tachometer
                                                            • 157 Alternating Current Induction Tachometer
                                                            • 158 Eddy Current Transducers
                                                            • 159 Variable-Capacitance Transducers
                                                              • 1591 Capacitive Displacement Sensors
                                                              • 1592 Capacitive Angular Velocity Sensor
                                                              • 1593 Capacitance Bridge Circuit
                                                                • 1510 Piezoelectric Transducers
                                                                  • 15101 Sensitivity
                                                                  • 15102 Piezoelectric Accelerometer
                                                                  • 15103 Charge Amplifier
                                                                      • 16 Torque Force and Other Sensors
                                                                        • 161 Strain Gage Sensors
                                                                          • 1611 Equations for Strain Gage Measurements
                                                                          • 1612 Bridge Sensitivity
                                                                          • 1613 The Bridge Constant
                                                                          • 1614 The Calibration Constant
                                                                          • 1615 Data Acquisition
                                                                          • 1616 Accuracy Considerations
                                                                          • 1617 Semiconductor Strain Gages
                                                                          • 1618 Force and Torque Sensors
                                                                          • 1619 Strain Gage Torque Sensors
                                                                          • 16110 Deflection Torque Sensors
                                                                          • 16111 Variable-Reluctance Torque Sensor
                                                                          • 16112 Reaction Torque Sensors
                                                                            • 162 Miscellaneous Sensors
                                                                              • 1621 Stroboscope
                                                                              • 1622 Fiber Optic Sensors and Lasers
                                                                              • 1623 Fiber-Optic Gyroscope
                                                                              • 1624 Laser Doppler Interferometer
                                                                              • 1625 Ultrasonic Sensors
                                                                              • 1626 Gyroscopic Sensors
                                                                                  • References
                                                                                  • Appendix 1A Virtual Instrumentation for Data Acquisition Analysis and Presentation
                                                                                    • Summary
                                                                                    • List of Abbreviations
                                                                                    • 1A1 Dynamic Signals
                                                                                      • 1A11 Acquiring and Simulating Dynamic Signals
                                                                                        • 1A111 Aliasing
                                                                                        • 1A112 Time Continuity
                                                                                            • 1A2 Measurement Configuration Considerations
                                                                                              • 1A21 Input Signal Considerations
                                                                                                • 1A211 Input Pseudodifferential and Differential Configuration
                                                                                                • 1A212 Gain
                                                                                                • 1A213 Input Coupling
                                                                                                • 1A214 Integrated Electronic Piezoelectric Excitation
                                                                                                • 1A215 Nyquist Frequency and Bandwidth
                                                                                                • 1A216 Analog-to-Digital Conversion
                                                                                                • 1A217 Antialias Filters
                                                                                                • 1A218 Input Filter Delay
                                                                                                • 1A219 Overload Detection
                                                                                                  • 1A22 Output Signal Considerations
                                                                                                    • 1A221 Output Pseudodifferential and Differential Configuration
                                                                                                    • 1A222 Attenuation
                                                                                                    • 1A223 Digital-to-Analog Conversion
                                                                                                    • 1A224 Anti-imaging and Interpolation Filters
                                                                                                    • 1A225 Output Filter Delay
                                                                                                        • 1A3 Scaling and Calibration
                                                                                                          • 1A31 Scaling to Engineering Units
                                                                                                          • 1A32 Performing System Calibration
                                                                                                            • 1A321 Propagation Delay Calibration
                                                                                                                • 1A4 Limit Testing Analysis
                                                                                                                  • 1A41 Limit Testing Overview
                                                                                                                  • 1A42 Using the SVT Limit Testing VI
                                                                                                                    • 1A5 Integration
                                                                                                                      • 1A51 Introduction to Integration
                                                                                                                      • 1A52 Implementing Integration
                                                                                                                        • 1A521 Challenges when Integrating Vibration Data
                                                                                                                          • 1A53 Time-Domain Integration
                                                                                                                            • 1A531 Single-Shot Acquisition and Integration
                                                                                                                            • 1A532 Continuous Acquisition and Integration
                                                                                                                              • 1A54 Frequency-Domain Integration
                                                                                                                                • 1A6 Vibration-Level Measurements
                                                                                                                                  • 1A61 Measuring the Root Mean Square Level
                                                                                                                                    • 1A611 Single-Shot Buffered Acquisition
                                                                                                                                    • 1A612 Continuous Signal Acquisition
                                                                                                                                      • 1A62 Performing a Running RMS Level Measurement
                                                                                                                                      • 1A63 Computing the Peak Level
                                                                                                                                      • 1A64 Computing the Crest Factor
                                                                                                                                        • 1A7 Frequency Analysis
                                                                                                                                          • 1A71 FFT Fundamentals
                                                                                                                                            • 1A711 Number of Samples
                                                                                                                                            • 1A712 Frequency Resolution
                                                                                                                                            • 1A713 Maximum Resolvable Frequency
                                                                                                                                            • 1A714 Minimum Resolvable Frequency
                                                                                                                                            • 1A715 Number of Spectral Lines
                                                                                                                                            • 1A716 Relationship between Time-Domain and Frequency-Domain Specifications and Parameters
                                                                                                                                              • 1A72 Increasing Frequency Resolution
                                                                                                                                                • 1A721 Zoom FFT Analysis
                                                                                                                                                • 1A722 Frequency Resolution of the Zoom FFT VIs
                                                                                                                                                • 1A723 Zoom Measurement
                                                                                                                                                • 1A724 Zoom Settings
                                                                                                                                                • 1A725 Subset Analysis
                                                                                                                                                    • 1A8 Transient Analysis
                                                                                                                                                      • 1A81 Transient Analysis with the Sound and Vibration Toolkit
                                                                                                                                                      • 1A82 Performing an STFT vs Time
                                                                                                                                                        • 1A821 Selecting the FFT Block Size
                                                                                                                                                        • 1A822 Overlapping
                                                                                                                                                        • 1A823 Using the SVT STFT vs Time VI
                                                                                                                                                          • 1A83 Performing an STFT vs Rotational Speed
                                                                                                                                                            • 1A831 Converting the Pulse Train to Rotational Speed
                                                                                                                                                            • 1A832 STFT vs RPM
                                                                                                                                                              • 1A84 Measuring a Shock Response Spectrum
                                                                                                                                                                • 1A9 Waterfall Display
                                                                                                                                                                  • 1A91 Using the Display VIs
                                                                                                                                                                    • 1A911 Initializing the Display
                                                                                                                                                                    • 1A912 Sending Data to the Display
                                                                                                                                                                    • 1A913 Waterfall Display for Frequency Analysis
                                                                                                                                                                    • 1A914 Waterfall Display for Transient Analysis
                                                                                                                                                                    • 1A915 Waterfall Display for Octave Spectra
                                                                                                                                                                        • 1A10 Swept-Sine Measurements
                                                                                                                                                                          • 1A101 Swept-Sine Overview
                                                                                                                                                                          • 1A102 Choosing Swept-Sine vs FFT Measurements
                                                                                                                                                                          • 1A103 Taking a Swept-Sine Measurement
                                                                                                                                                                          • 1A104 Swept-Sine Measurement Example
                                                                                                                                                                              • Bibliography
                                                                                                                                                                              • Related Titles
                                                                                                                                                                                  • 53191ch2
                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                    • Chapter 2 Signal Conditioning and Modification
                                                                                                                                                                                      • Summary
                                                                                                                                                                                      • 21 Introduction
                                                                                                                                                                                      • 22 Amplifiers
                                                                                                                                                                                        • 221 Operational Amplifier
                                                                                                                                                                                        • 222 Use of Feedback in Opamp
                                                                                                                                                                                        • 223 Voltage Current and Power Amplifiers
                                                                                                                                                                                          • 2231 Charge Amplifiers
                                                                                                                                                                                            • 224 Instrumentation Amplifiers
                                                                                                                                                                                              • 2241 Differential Amplifier
                                                                                                                                                                                              • 2242 Common Mode
                                                                                                                                                                                                • 225 Amplifier Performance Ratings
                                                                                                                                                                                                  • 2251 Common-Mode Rejection Ratio
                                                                                                                                                                                                    • 226 Component Interconnection
                                                                                                                                                                                                      • 2261 Impedance Characteristics
                                                                                                                                                                                                      • 2262 Cascade Connection of Devices
                                                                                                                                                                                                      • 2263 AC-Coupled Ampliers
                                                                                                                                                                                                          • 23 Analog Filters
                                                                                                                                                                                                            • 231 Passive Filters and Active Filters
                                                                                                                                                                                                              • 2311 Number of Poles
                                                                                                                                                                                                                • 232 Low-Pass Filters
                                                                                                                                                                                                                  • 2321 Low-Pass Butterworth Filter
                                                                                                                                                                                                                    • 233 High-Pass Filters
                                                                                                                                                                                                                    • 234 Band-Pass Filters
                                                                                                                                                                                                                      • 2341 Resonance-Type Band-Pass Filters
                                                                                                                                                                                                                        • 235 Band-Reject Filters
                                                                                                                                                                                                                          • 24 Modulators and Demodulators
                                                                                                                                                                                                                            • 241 Amplitude Modulation
                                                                                                                                                                                                                              • 2411 Modulation Theorem
                                                                                                                                                                                                                              • 2412 Side Frequencies and Side Bands
                                                                                                                                                                                                                                • 242 Application of Amplitude Modulation
                                                                                                                                                                                                                                  • 2421 Fault Detection and Diagnosis
                                                                                                                                                                                                                                    • 243 Demodulation
                                                                                                                                                                                                                                      • 25 Analog ndashDigital Conversion
                                                                                                                                                                                                                                        • 251 Digital-to-Analog Conversion
                                                                                                                                                                                                                                          • 2511 DAC Error Sources
                                                                                                                                                                                                                                            • 252 Analog-to-Digital Conversion
                                                                                                                                                                                                                                            • 253 Analog-to-Digital Converter Performance Characteristics
                                                                                                                                                                                                                                              • 2531 Resolution and Quantization Error
                                                                                                                                                                                                                                              • 2532 Monotonicity Nonlinearity and Offset Error
                                                                                                                                                                                                                                              • 2533 Analog-to-Digital Converter Conversion Rate
                                                                                                                                                                                                                                                • 254 Sample-and-Hold Circuitry
                                                                                                                                                                                                                                                • 255 Digital Filters
                                                                                                                                                                                                                                                  • 2551 Software Implementation and Hardware Implementation
                                                                                                                                                                                                                                                      • 26 Bridge Circuits
                                                                                                                                                                                                                                                        • 261 Wheatstone Bridge
                                                                                                                                                                                                                                                        • 262 Constant-Current Bridge
                                                                                                                                                                                                                                                        • 263 Bridge Amplifiers
                                                                                                                                                                                                                                                          • 2631 Half-Bridge Circuits
                                                                                                                                                                                                                                                            • 264 Impedance Bridges
                                                                                                                                                                                                                                                              • 2641 Owen Bridge
                                                                                                                                                                                                                                                              • 2642 Wien-Bridge Oscillator
                                                                                                                                                                                                                                                                  • 27 Linearizing Devices
                                                                                                                                                                                                                                                                    • 271 Linearization by Software
                                                                                                                                                                                                                                                                    • 272 Linearization by Hardware Logic
                                                                                                                                                                                                                                                                    • 273 Analog Linearizing Circuitry
                                                                                                                                                                                                                                                                    • 274 Offsetting Circuitry
                                                                                                                                                                                                                                                                    • 275 Proportional-Output Circuitry
                                                                                                                                                                                                                                                                      • 2751 Curve-Shaping Circuitry
                                                                                                                                                                                                                                                                          • 28 Miscellaneous Signal Modification Circuitry
                                                                                                                                                                                                                                                                            • 281 Phase Shifters
                                                                                                                                                                                                                                                                            • 282 Voltage-to-Frequency Converter
                                                                                                                                                                                                                                                                            • 283 Frequency-to-Voltage Converter
                                                                                                                                                                                                                                                                            • 284 Voltage-to-Current Converters
                                                                                                                                                                                                                                                                            • 285 Peak-Hold Circuits
                                                                                                                                                                                                                                                                              • 29 Signal Analyzers and Display Devices
                                                                                                                                                                                                                                                                                • 291 Signal Analyzers
                                                                                                                                                                                                                                                                                • 292 Oscilloscopes
                                                                                                                                                                                                                                                                                  • 2921 Triggering
                                                                                                                                                                                                                                                                                  • 2922 Lissajous Patterns
                                                                                                                                                                                                                                                                                  • 2923 Digital Oscilloscopes
                                                                                                                                                                                                                                                                                      • Bibliography
                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                          • 53191ch3
                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                            • Chapter 3 Vibration Testing
                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                              • 31 Introduction
                                                                                                                                                                                                                                                                                              • 32 Representation of a Vibration Environment
                                                                                                                                                                                                                                                                                                • 321 Test Signals
                                                                                                                                                                                                                                                                                                  • 3211 Stochastic vs Deterministic Signals
                                                                                                                                                                                                                                                                                                    • 322 Deterministic Signal Representation
                                                                                                                                                                                                                                                                                                      • 3221 Single-Frequency Signals
                                                                                                                                                                                                                                                                                                      • 3222 Sine Sweep
                                                                                                                                                                                                                                                                                                      • 3223 Sine Dwell
                                                                                                                                                                                                                                                                                                      • 3224 Decaying Sine
                                                                                                                                                                                                                                                                                                      • 3225 Sine Beat
                                                                                                                                                                                                                                                                                                      • 3226 Sine Beat with Pauses
                                                                                                                                                                                                                                                                                                      • 3227 Multifrequency Signals
                                                                                                                                                                                                                                                                                                      • 3228 Actual Excitation Records
                                                                                                                                                                                                                                                                                                      • 3229 Simulated Excitation Signals
                                                                                                                                                                                                                                                                                                        • 323 Stochastic Signal Representation
                                                                                                                                                                                                                                                                                                          • 3231 Ergodic Random Signals
                                                                                                                                                                                                                                                                                                          • 3232 Stationary Random Signals
                                                                                                                                                                                                                                                                                                          • 3233 Independent and Uncorrelated Signals
                                                                                                                                                                                                                                                                                                          • 3234 Transmission of Random Excitations
                                                                                                                                                                                                                                                                                                            • 324 Frequency-Domain Representations
                                                                                                                                                                                                                                                                                                              • 3241 Fourier Spectrum Method
                                                                                                                                                                                                                                                                                                              • 3242 Power Spectral Density Method
                                                                                                                                                                                                                                                                                                                • 325 Response Spectrum
                                                                                                                                                                                                                                                                                                                  • 3251 Displacement Velocity and Acceleration Spectra
                                                                                                                                                                                                                                                                                                                  • 3252 Response-Spectra Plotting Paper
                                                                                                                                                                                                                                                                                                                  • 3253 Zero-Period Acceleration
                                                                                                                                                                                                                                                                                                                  • 3254 Uses of Response Spectra
                                                                                                                                                                                                                                                                                                                    • 326 Comparison of Various Representations
                                                                                                                                                                                                                                                                                                                      • 33 Pretest Procedures
                                                                                                                                                                                                                                                                                                                        • 331 Purpose of Testing
                                                                                                                                                                                                                                                                                                                        • 332 Service Functions
                                                                                                                                                                                                                                                                                                                          • 3321 Active Equipment
                                                                                                                                                                                                                                                                                                                          • 3322 Passive Equipment
                                                                                                                                                                                                                                                                                                                          • 3323 Functional Testing
                                                                                                                                                                                                                                                                                                                            • 333 Information Acquisition
                                                                                                                                                                                                                                                                                                                              • 3331 Interface Details
                                                                                                                                                                                                                                                                                                                              • 3332 Effect of Neglecting Interface Dynamics
                                                                                                                                                                                                                                                                                                                              • 3333 Effects of Damping
                                                                                                                                                                                                                                                                                                                              • 3334 Effects of Inertia
                                                                                                                                                                                                                                                                                                                              • 3335 Effect of Natural Frequency
                                                                                                                                                                                                                                                                                                                              • 3336 Effect of Excitation Frequency
                                                                                                                                                                                                                                                                                                                              • 3337 Other Effects of Interface
                                                                                                                                                                                                                                                                                                                                • 334 Test-Program Planning
                                                                                                                                                                                                                                                                                                                                  • 3341 Testing of Cabinet-Mounted Equipment
                                                                                                                                                                                                                                                                                                                                    • 335 Pretest Inspection
                                                                                                                                                                                                                                                                                                                                      • 34 Testing Procedures
                                                                                                                                                                                                                                                                                                                                        • 341 Resonance Search
                                                                                                                                                                                                                                                                                                                                        • 342 Methods of Determining Frequency-Response Functions
                                                                                                                                                                                                                                                                                                                                          • 3421 Fourier Transform Method
                                                                                                                                                                                                                                                                                                                                          • 3422 Spectral Density Method
                                                                                                                                                                                                                                                                                                                                          • 3423 Harmonic Excitation Method
                                                                                                                                                                                                                                                                                                                                            • 343 Resonance-Search Test Methods
                                                                                                                                                                                                                                                                                                                                              • 3431 Hammer (Bump) Test and Drop Test
                                                                                                                                                                                                                                                                                                                                              • 3432 Pluck Test
                                                                                                                                                                                                                                                                                                                                              • 3433 Shaker Tests
                                                                                                                                                                                                                                                                                                                                                • 344 Mechanical Aging
                                                                                                                                                                                                                                                                                                                                                  • 3441 Equivalence for Mechanical Aging
                                                                                                                                                                                                                                                                                                                                                  • 3442 Excitation-Intensity Equivalence
                                                                                                                                                                                                                                                                                                                                                  • 3443 Dynamic-Excitation Equivalence
                                                                                                                                                                                                                                                                                                                                                  • 3444 Cumulative Damage Theory
                                                                                                                                                                                                                                                                                                                                                    • 345 Test-Response Spectrum Generation
                                                                                                                                                                                                                                                                                                                                                    • 346 Instrument Calibration
                                                                                                                                                                                                                                                                                                                                                    • 347 Test-Object Mounting
                                                                                                                                                                                                                                                                                                                                                    • 348 Test-Input Considerations
                                                                                                                                                                                                                                                                                                                                                      • 3481 Test Nomenclature
                                                                                                                                                                                                                                                                                                                                                      • 3482 Testing with Uncorrelated Excitations
                                                                                                                                                                                                                                                                                                                                                      • 3483 Symmetrical Rectilinear Testing
                                                                                                                                                                                                                                                                                                                                                      • 3484 Geometry vs Dynamics
                                                                                                                                                                                                                                                                                                                                                      • 3485 Some Limitations
                                                                                                                                                                                                                                                                                                                                                      • 3486 Testing Black Boxes
                                                                                                                                                                                                                                                                                                                                                      • 3487 Phasing of Excitations
                                                                                                                                                                                                                                                                                                                                                      • 3488 Testing a Gray or White Box
                                                                                                                                                                                                                                                                                                                                                      • 3489 Overtesting in Multitest Sequences
                                                                                                                                                                                                                                                                                                                                                          • 35 Some Practical Information
                                                                                                                                                                                                                                                                                                                                                            • 351 Random Vibration Test Example
                                                                                                                                                                                                                                                                                                                                                            • 352 Vibration Shakers and Control Systems
                                                                                                                                                                                                                                                                                                                                                              • Bibliography
                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                  • 53191ch4
                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                    • Chapter 4 Experimental Modal Analysis
                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                      • 41 Introduction
                                                                                                                                                                                                                                                                                                                                                                      • 42 Frequency-Domain Formulation
                                                                                                                                                                                                                                                                                                                                                                        • 421 Transfer-Function Matrix
                                                                                                                                                                                                                                                                                                                                                                        • 422 Principle of Reciprocity
                                                                                                                                                                                                                                                                                                                                                                          • 43 Experimental Model Development
                                                                                                                                                                                                                                                                                                                                                                            • 431 Extraction of the Time-Domain Model
                                                                                                                                                                                                                                                                                                                                                                              • 44 Curve Fitting of Transfer Functions
                                                                                                                                                                                                                                                                                                                                                                                • 441 Problem Identification
                                                                                                                                                                                                                                                                                                                                                                                • 442 Single- and Multi-Degree-of-Freedom Techniques
                                                                                                                                                                                                                                                                                                                                                                                • 443 Single-Degree-of-Freedom Parameter Extraction in the Frequency Domain
                                                                                                                                                                                                                                                                                                                                                                                  • 4431 Circle-Fit Method
                                                                                                                                                                                                                                                                                                                                                                                    • Case of Viscous Damping
                                                                                                                                                                                                                                                                                                                                                                                    • Case of Hysteretic Damping
                                                                                                                                                                                                                                                                                                                                                                                      • 4432 Peak-Picking Method
                                                                                                                                                                                                                                                                                                                                                                                        • 444 Multi-Degree of Freedom Curve Fitting
                                                                                                                                                                                                                                                                                                                                                                                          • 4441 Formulation of the Method
                                                                                                                                                                                                                                                                                                                                                                                            • 445 A Comment on Static Modes and Rigid-Body Modes
                                                                                                                                                                                                                                                                                                                                                                                            • 446 Residue Extraction
                                                                                                                                                                                                                                                                                                                                                                                              • 45 Laboratory Experiments
                                                                                                                                                                                                                                                                                                                                                                                                • 451 Lumped-Parameter System
                                                                                                                                                                                                                                                                                                                                                                                                  • 4511 Frequency-Domain Test
                                                                                                                                                                                                                                                                                                                                                                                                  • 4512 Time-Domain Tests
                                                                                                                                                                                                                                                                                                                                                                                                    • 452 Distributed-Parameter System
                                                                                                                                                                                                                                                                                                                                                                                                      • 46 Commercial EMA Systems
                                                                                                                                                                                                                                                                                                                                                                                                        • 461 System Configuration
                                                                                                                                                                                                                                                                                                                                                                                                          • 4611 FFT Analysis Options
                                                                                                                                                                                                                                                                                                                                                                                                          • 4612 Modal Analysis Components
                                                                                                                                                                                                                                                                                                                                                                                                              • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                              • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                  • 53191ch5
                                                                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                    • Chapter 5 Mechanical Shock
                                                                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                      • 51 Definitions
                                                                                                                                                                                                                                                                                                                                                                                                                        • 511 Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 512 Simple (or Perfect) Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 513 Half-Sine Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 514 Versed-Sine (or Haversine) Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 515 Terminal Peak Sawtooth Shock or Final Peak Sawtooth Shock
                                                                                                                                                                                                                                                                                                                                                                                                                        • 516 Rectangular Shock
                                                                                                                                                                                                                                                                                                                                                                                                                          • 5161 Trapezoidal Shock
                                                                                                                                                                                                                                                                                                                                                                                                                              • 52 Description in the Time Domain
                                                                                                                                                                                                                                                                                                                                                                                                                              • 53 Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                • 531 Need
                                                                                                                                                                                                                                                                                                                                                                                                                                • 532 Shock Response Spectrum Definition
                                                                                                                                                                                                                                                                                                                                                                                                                                • 533 Response of a Linear One-Degree-of-Freedom System
                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5331 Shock Defined by a Force
                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5332 Shock Defined by an Acceleration
                                                                                                                                                                                                                                                                                                                                                                                                                                    • 534 Definitions
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5341 Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5342 Absolute Acceleration Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5343 Relative Displacement Shock Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5344 Primary Positive Shock Response Spectrum or Initial Positive Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5345 Primary (or Initial) Negative Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5346 Secondary (or Residual) Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5347 Positive (or Maximum Positive) Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5348 Negative (or Maximum Negative) Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5349 Maximax Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53410 Choice of Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                        • 535 Standardized Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5351 Definition
                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5352 Standardized Shock Response Spectra of Simple Shocks
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53521 Half-Sine Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53522 Versed Sine Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53523 Terminal Peak Sawtooth Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53524 Rectangular Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                            • 53525 Trapezoidal Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 536 Choice of Damping
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 537 Shock Response Spectra Domains
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 538 Algorithms for Calculation of the Shock Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 539 Choice of the Digitization Frequency of the Signal
                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5310 Use of Shock Response Spectra for the Study of Systems with Several Degrees of Freedom
                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 54 Pyroshocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 55 Use of Shock Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 551 Severity Comparison of Several Shocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 552 Test Specification Development from Real Environment Data
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5521 Synthesis of Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5522 Nature of the Specification
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5523 Choice of Shape
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5524 Amplitude
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5525 Duration
                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5526 Difficulties
                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 56 Standards
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 561 Types of Standards
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 562 Installation Conditions of Test Item
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 563 Uncertainty Factor
                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 564 Bump Test
                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 57 Damage Boundary Curve
                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 571 Definition
                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 572 Analysis of Test Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 58 Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 581 Main Types
                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 582 Impact Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5821 Universal Shock-Test Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 58211 Impact Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 58212 Impulse Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 583 Shock Simulators (Programmers)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5831 Half-Sine Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58311 Shock Duration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58312 Impact Velocity
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58313 Maximum Deformation of the Shock Simulator (Programmer)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58314 Shock Amplitude
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 58315 Characteristics of the Target
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5832 Terminal Peak Sawtooth Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5833 Rectangular Pulse ndash Trapezoidal Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5834 Universal Shock Simulator (Programmer)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 58341 Generating a Half-Sine Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 58342 Generating a Terminal Peak Sawtooth Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 58343 Trapezoidal Shock Pulse
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 584 Limitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5841 Limitations of the Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5842 Limitations of Shock Simulators
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 585 Pneumatic Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 586 High Impact Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5861 Lightweight High Impact Shock Machine
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5862 Medium Weight High Impact Shock Machine
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 587 Specific Test Facilities
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 59 Generation of Shock Using Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 591 Principle Behind the Generation of a Simple Shape Signal versus Time
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 592 Main Advantages
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 593 Pre- and Postshocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5931 Requirements
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 5932 Solutions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 59321 Optimized Pre- and Postpulses
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 5933 Incidence on the Shock Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 594 Limitations of Electrodynamic Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 5941 Mechanical Limitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 59411 Abacuses
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 5942 Electronic Limitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 595 The Use of Electrohydraulic Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 510 Control by a Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 5101 Principle
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 5102 Principal Shapes of Elementary Signals
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 51021 Decaying Sinusoid
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 51022 ZERD Function
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 51023 WAVSIN Waveform
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 5103 Comparison of WAVSIN SHOC Waveforms and Decaying Sinusoid
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 5104 Criticism of Control by a Shock Response Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 511 Pyrotechnic Shock Simulation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5111 Simulation Using Pyrotechnic Facilities
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5112 Simulation Using Metal-to-Metal Impact
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5113 Simulation Using Electrodynamic Shakers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 5114 Simulation Using Conventional Shock Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53191ch6
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Chapter 6 Machine Condition Monitoring and Fault Diagnostics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 61 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 62 Machinery Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 621 Causes of Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 622 Types of Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 623 Frequency of Failure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 63 Basic Maintenance Strategies
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 631 Run-to-Failure (Breakdown) Maintenance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 632 Scheduled (Preventative) Maintenance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 633 Condition-Based (Predictive Proactive Reliability Centered On-Condition) Maintenance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 64 Factors Which Influence Maintenance Strategy
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 65 Machine Condition Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 651 Periodic Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 652 Continuous Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 66 Transducer Selection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 661 Noncontact Displacement Transducers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 662 Velocity Transducers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 663 Acceleration Transducers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 67 Transducer Location
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 68 Recording and Analysis Instrumentation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 681 Vibration Meters
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 682 Data Collectors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 683 Frequency-Domain Analyzers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 684 Time-Domain Instruments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 685 Tracking Analyzers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 69 Display Formats and Analysis Tools
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 691 Time Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6911 Time-Waveform Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6912 Time-Waveform Indices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6913 Time-Synchronous Averaging
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6914 Negative Averaging
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6915 Orbits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6916 Probability Density Functions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 6917 Probability Density Moments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 692 Frequency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6921 Band-Pass Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6922 Shock Pulse (Spike Energy)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6923 Enveloped Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6924 Signature Spectrum
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6925 Cascades (Waterfall Plots)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6926 Masks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 6927 Frequency-Domain Indices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 693 Modal Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 694 Quefrency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 610 Fault Detection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 6101 Standards
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61011 Standards Based on Machinery Type
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61012 Standards Based on Vibration Severity
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 6102 Acceptance Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 61021 Statistical Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 6103 Frequency-Domain Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61031 Limited Band Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61032 Constant Bandwidth Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61033 Constant Percentage Bandwidth Limits
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 611 Fault Diagnostics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 6111 Forcing Functions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61111 Unbalance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61112 Misalignment
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61113 Mechanical Looseness
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61114 Soft Foot
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61115 Rubs
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61116 Resonances
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61117 Oil Whirl
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61118 Oil Whip
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 61119 Structural Vibrations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 611110 Foundation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 6112 Specific Machine Components
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 61121 Damaged or Worn Rolling-Element Bearings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 61122 Damaged or Worn Gears
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 6113 Specific Machine Types
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61131 Pumps
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61132 Fans
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61133 Electric Motors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61134 Steam and Gas Turbines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61135 Compressors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 61136 Reciprocating Machines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 6114 Advanced Fault Diagnostic Techniques
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 53191ch7
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • Chapter 7 Vibration-Based Tool Condition Monitoring Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 71 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 72 Mechanics of Turning
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 721 General Terms
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 722 Chatter Vibrations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 723 Tool Wear
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7231 Tool Failure Mechanisms
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7232 Tool Failure Modes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7233 Tool Wear Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7234 Tool Wear Stages
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 73 Vibration Signal Recording
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 731 Direct and Indirect Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 732 Sensor Requirements for Tool Wear Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 733 Force Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7331 Direct Measurement Dynamometers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7332 Indirect Force Sensors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7333 Piezoelectric Strain Sensors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7334 Resistance Strain Gauges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7335 Customized Force Sensors
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 734 Acceleration Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 735 Acoustic Emission Measurement
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 736 Sensor Comparisons
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 74 Signal Processing for Sensor-Based Tool Condition Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 741 Feature Extraction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7411 Time Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7412 Frequency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7413 Statistical Processing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 7414 TimendashFrequency Domain
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 742 Feature Selection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 75 Wear ModelDecision-Making for Sensor-Based Tool Condition Monitoring
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 751 Trending Threshold
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 752 Neural Networks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7521 Unsupervised Networks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 7522 Supervised Networks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 753 Fuzzy Logic
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 754 Other Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 76 Conclusion
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53191ch8
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Chapter 8 Fault Diagnosis of Helicopter Gearboxes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 81 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 82 Abnormality Scaling
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 83 The Structure-Based Connectionist Network
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 84 Sensor Location Selection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 841 Coverage Index
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 842 Overlap Index
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 843 Monitoring Effectiveness
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 85 A Case Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 851 Structural and Featural Influences
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 852 Evaluation of Influences
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 853 Fault Detection Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 854 Fault Diagnostic Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 8541 Faulty Subsystem Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 8542 Faulty Component Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 855 Sensor Location Evaluation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 856 Sensor Location Validation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 86 Conclusion
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 53191ch9
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Chapter 9 Vibration Suppression and Monitoring in Precision Motion Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 91 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 92 Mechanical Design to Minimize Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 921 Stability and Static Determinacy of Machine Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 922 Two-Dimensional Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 923 Three-Dimensional Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 93 Adaptive Notch Filter
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 931 Fast Fourier Transform
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 932 Simulation and Experiments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 94 Real-Time Vibration Analyzer
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 941 Learning Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 942 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 943 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 944 Experiments
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 9441 Input Variables mdash the Evaluation Criteria
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 94411 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 94412 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 9442 Evaluation Rules
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 94421 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 94422 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 9443 Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 94431 Monitoring Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 94432 Diagnostic Mode
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 95 Practical Insights and Case Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 96 Conclusions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 53191ch10
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Chapter 10 Vibration and Shock Problems of Civil Engineering Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 101 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 102 Earthquake-Induced Vibration of Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1021 Seismicity and Ground Motions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1022 Influence of Local Site Conditions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1023 Response of Structures to Ground Motions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1024 Dynamic Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10241 Equations of Motion for Linear Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10242 Equations of Motion for Linear Multiple-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1025 Earthquake Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10251 Elastic Response Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10252 Smoothed Design Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10253 Ductility-Modified Response Spectrum Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1026 Design Philosophy and the Code Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10261 Performance-Based Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1027 Analysis Options for Earthquake Effects
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10271 Dynamic Time History Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10272 Response Spectrum Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 102721 Response Spectrum Analysis of Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 102722 Response Spectrum Analysis of Multi-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10273 Equivalent Static Analysis (Force-Based Approach)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10274 Displacement-Based Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1028 SoilndashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1029 Active and Passive Control Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 10210 Worked Examples
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 103 Dynamic Effects of Wind Loading on Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1031 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1032 Wind Speed
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1033 Design Structures for Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10331 Types of Wind Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10332 Design Criteria
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10333 Static Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1034 Along and Across-Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10341 Along-Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10342 Across-Wind Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1035 Wind Tunnel Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1036 Comfort Criteria Human Response to Building Motion
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1037 Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1038 Comparison with Earthquake Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 104 Vibrations Due to Fluid ndashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1041 Added Mass and Inertial Coupling
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1042 Wave-Induced Vibration of Structure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 105 Blast Loading and Blast Effects on Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1051 Explosions and Blast Phenomenon
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1052 Explosive Air-Blast Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10521 Blast Wave Scaling Laws
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10522 Prediction of Blast Pressure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1053 Gas Explosion Loading and Effect of Internal Explosions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1054 Structural Response to Blast Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10541 Elastic Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10542 Elasto-Plastic Single-Degree-of-Freedom Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1055 Material Behaviors at High Strain Rate
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10551 Dynamic Properties of Concrete under High Strain Rates
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10552 Dynamic Properties of Reinforcing Steel under High Strain Rates
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1056 Failure Modes of Blast-Loaded Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10561 Global Structural Behavior
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10562 Localized Structural Behavior
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10563 PressurendashImpulse ( PndashI ) Diagrams
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1057 Blast WavendashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1058 Effect of Ground Shocks
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10581 Loads from Air-Induced Ground Shock
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10582 Loads from Direct Ground Shock
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1059 Technical Design Manuals for Blast-Resistant Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 10510 Computer Programs for Blast and Shock Effects
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 106 Impact Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1061 Structural Impact between Two Bodies mdash Hard Impact and Soft Impact
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1062 Example mdash Aircraft Impact
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 107 Floor Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1071 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1072 Types of Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10721 Walking
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10722 Rhythmic Activities
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10723 Mechanical Equipment
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 10724 Analysis Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1073 Natural Frequency of Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10731 Computing the Natural Frequency
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10732 Computing Deflection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10733 Damping
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 10734 Resonance
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1074 Vibration Caused by Walking
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 10741 Minimum Natural Frequency
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1075 Design for Rhythmic Excitation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10751 Harmonics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 10752 Minimum Natural Frequency
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1076 Example mdash Vibration Analysis of a Reinforced Concrete Floor
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 53191ch11
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • Chapter 11 Seismic Base Isolation and Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 111 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1111 From Ductility Design to Base Isolation and Control Design
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1112 The Importance of Reducing Seismic Input and Response
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 112 Seismic Base Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1121 Historical Development of Base Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1122 Basic Principle
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1123 Issues in Seismic Base Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11231 Performance Criteria
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11232 Type of Structure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11233 Site Characteristics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11234 Retrofit Issues
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11235 Design of Building Services
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11236 Expected Life of Isolator
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1124 Seismic Isolation Devices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11241 Laminated Rubber Bearings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11242 Lead Rubber Bearing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11243 Friction-Based Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11244 Other Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1125 Design of Isolation Devices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11251 High-Damping Rubber Bearing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112511 Stability against Buckling
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112512 Stability against Roll Out
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11252 Lead Rubber Bearings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112521 Design of Lead Plug
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112522 Design of Laminated Rubber Bearing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11253 Design of Friction Pendulum System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1126 Verification of Properties of Isolation Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11261 Tests for Isolation Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 112611 System Characterization Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 112612 Prototype Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 112613 Quality Control Tests
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11262 Uniform Building Code Recommendations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112621 Units Dependent on Loading Rates
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112622 Units Dependent on Bilateral Load
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112623 System Adequacy
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1127 Analysis of Base-Isolated Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11271 Modeling of a Superstructure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11272 Modeling of Isolation System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11273 Static Analysis Procedure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11274 Dynamic Analysis Procedure
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 112741 Response Spectrum Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 112742 Time-History Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11275 Software for Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1128 Experimental Methods for Isolated Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1129 Implementation of Seismic Isolation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11291 New Construction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112911 Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 112912 Bridges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11292 Seismic Retrofit
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112921 Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 112922 Bridges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11293 Other Implementations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 11210 Performance during Past Earthquakes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 112101 Performance of Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 112102 Performance of Bridges
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 113 Seismic Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1131 Historical Development of Seismic Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1132 Basic Principles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11321 Passive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11322 Active Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11323 Semiactive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11324 Hybrid Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11325 Categorization of Basic Principles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1133 Important Issues in Vibration Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11331 SoilndashStructure Interaction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11332 DevicendashStructure Interaction and Time Delay
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11333 Design Guidelines
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1134 Vibration-Control Devices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11341 Passive Control Systems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113411 Metallic Yielding Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113412 Friction Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113413 Viscoelastic Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113414 Viscous Fluid Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113415 Tuned Mass Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11342 Active Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113421 Electromagnetic Actuator
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113422 Hydraulic Actuators
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11343 Semiactive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113431 Variable-Orifice Hydraulic Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113432 Controllable Fluid Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113433 Controllable Friction Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 11344 Hybrid Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1135 Control Algorithm
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11351 Active Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11352 Semiactive Control System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113521 Common Control Schemes for Controllable Dampers
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113522 Special Control Schemes for Controllable Damper
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1136 Experimental Performance Verification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11361 Shaking Table Tests of a Flexible Structural Model with TMD AMD and ATMD
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 11362 Substructure Hybrid Test
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113621 Hybrid Tests Using Hydraulic Actuator
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113622 Hybrid Tests Using Shaking Table
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 113623 Hybrid Tests Using Inertia-Force-Driven Loading System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1137 Implementations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 11371 Semiactive Control of Full-Scale Structures Using Variable Joint Damper System
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113711 Background of Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113712 Test System Set Up
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113713 Control Algorithm
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 113714 Test Results
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 11372 Application of Structural Control Technologies to Seismic Retrofit of a Cable-Stayed Bridge
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113721 Background of Study
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113722 Basic Concept of Seismic Retrofit
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113723 Modal Shape Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113724 Time-History Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113725 Soil ndash Structure Interaction Effect
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 113726 Semiactive Control
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Bibliography
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Related Titles
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 53191ch12
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • Chapter 12 Seismic Random Vibration of Long-Span Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 121 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1211 Basic Concepts of Random Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12111 Stationary Random Process
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12112 Nonstationary Random Process
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1212 Three Methods for Structural Seismic Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12121 Response Spectrum Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12122 Time-History Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12123 Random Vibration Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 121231 Davenport Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 121232 Vanmarcke Approach
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 12124 Comparisons of the Three Seismic-Analysis Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 122 Seismic Random-Excitation Fields
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1221 Power Spectral Density of Spatially Varying Ground Acceleration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1222 Several Coherence Models
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12221 FengndashHu Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12222 Harichandran ndashVanmarcke Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12223 LohndashYeh Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12224 OliveirandashHaondashPenzien Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12225 LucondashWong Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12226 QundashWangndashWang Model
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1223 Generation of Ground Acceleration Power Spectral Density Curves from Acceleration Response Spectrum Curves
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12231 Kaul Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12232 Iteration Scheme
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1224 Seismic Equations of Motion of Long-Span Structures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 1225 Seismic Waves and Their Geometrical Expressions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 123 Pseudoexcitation Method for Structural Random Vibration Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1231 Structures Subjected to Stationary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12311 Single Stationary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12312 Multiple Stationary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1232 Structures Subjected to Nonstationary Random Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 12321 Structures Subjected to Uniformly Modulated Evolutionary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 123211 Single Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 123212 Multiple Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12322 Structures Subjected to Nonuniformly Modulated Evolutionary Random Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 123221 Single Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 123222 Multiple Excitation Problems
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1233 Precise Integration Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12331 Precise Integration of Exponential Matrices
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 12332 Particular Solutions and Precise Integration Formulas for Various Forms of Loading
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 123321 Linear Loading Form (HPD-L Form)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 123322 Sinusoidal Loading Form (HPD-S Form)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 123323 Exponentially Decaying Sinusoidal Loading Form (HPD-E Form)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 124 Long-Span Structures Subjected to Stationary Random Ground Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1241 The Solution of Equations of Motion Using the Pseudoexcitation Method
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1242 Numerical Comparisons with Other Methods
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • 12421 Song-Hua-Jiang Suspension Bridge
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 124211 All Supports Move Uniformly
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 124212 Wave Passage Effect Is Taken into Account
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • 124213 Wave-Passage Effect and Incoherence Effect Are Jointly Taken into Account
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 12422 San Joaquin Concrete Bridge
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 125 Long-Span Structures Subjected to Nonstationary Random Ground Excitations
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1251 Modulation Functions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1252 The Formulas for Nonstationary Multiexcitation Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1253 Expected Extreme Values of Nonstationary Random Processes
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1254 Numerical Comparisons with the Corresponding Stationary Analysis
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 126 Conclusions
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • References
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Related Titles
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                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Table of Contents
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Chapter 13 Seismic Qualification of Equipment
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 131 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 132 Distribution Qualification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1321 Drive-Signal Generation
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1322 Distribution Spectra
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1323 Test Procedures
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 133 Seismic Qualification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1331 Stages of Seismic Qualification
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1332 Test Preliminaries
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1333 Single-Frequency Testing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1334 Multifrequency Testing
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1335 Generation of RRS Specifications
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • Bibliography
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                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    • Chapter 14 Human Response to Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • Summary
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 141 Introduction
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      • 142 Vibration Excitations on Humans
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        • 1421 Excitation Characteristics
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          • 143 Human Response to Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1431 Vibration Perception
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1432 Frequency Weighting Curve
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1433 Iso-Perception Curves
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            • 1434 Detection Threshold Curve
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              • 144 Regulation of Human Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1441 Acceptable Vibration Levels in Buildings
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1442 Whole-Body Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                • 1443 HandndashArm Vibration
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  • Bibliography
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